MEMBRANE ASSEMBLIES

BACKGROUND

[0001] Membrane assemblies can be useful to separate undesirable solid particles or matter from liquids. However, depending on the type of particles or matter that is in the solution, the membrane assembly may be particularly susceptible to fouling, which can damage the membrane assembly and even render it inoperable. There is therefore a need to develop membrane assemblies that are less susceptible to fouling, while still being effective at filtering a solution.

SUMMARY OF THE DISCLOSURE

[0002] According to various embodiments, a membrane can include a porous substrate.

The membrane can further include a carbon nanolayer disposed on the porous substrate. The carbon nanolayer can include graphite platelets at least partially embedded in nanocrystalline carbon. The membrane can further include an electrical contact area disposed on the carbon nanolayer.

[0003] According to various embodiments, a membrane can include a porous substrate.

The porous substrate can include a ceramic material, a polymeric material, a metal, a fabric, or a combination thereof. The membrane can further include a carbon nanolayer disposed on the porous substrate. The carbon nanolayer can include graphite platelets at least partially embedded in nanocrystalline carbon. A major dimension of the graphite platelets, individually, can be greater than an average pore size of an individual pore of the porous substrate. In some embodiments, the porous substrate and the carbon nanolayer directly contact one another. The membrane can further include an electronic contact area adapted to receive electrical voltage from a source coupled to the electrical contact area. The source of electrical voltage can be adapted to create an AC voltage, a DC voltage, or both.

[0004] According to various embodiments, a method of making a membrane is disclosed. The membrane can include a porous substrate. The membrane can further include a carbon nanolayer disposed on the porous substrate. The carbon nanolayer can include graphite platelets at least partially embedded in nanocrystalline carbon. The membrane can further include an electrical contact area disposed on the carbon nanolayer. The method includes at least partially coating a surface of the porous substrate with a composition of carbon particles. The method further includes buffing the carbon particles on the substrate at a force normal to the surface of the porous substrate.

[0005] According to further embodiments, a method of using a membrane is disclosed.

The membrane can include a porous substrate. The membrane can further include a carbon nanolayer disposed on the porous substrate. The carbon nanolayer can include graphite platelets at least partially embedded in nanocrystalline carbon. The membrane can further include an electrical contact area disposed on the carbon nanolayer. The method includes contacting a solution with the membrane such that at least a portion of the solution passes through the membrane.

BRIEF DESCRIPTION OF THE FIGURES

[0006] The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

[0007] FIG. l is a sectional view of a membrane assembly.

[0008] FIG. 2 is a schematic diagram showing a buff-coating process.

[0009] FIG. 3 A shows an experimental arrangement for testing a membrane assembly.

[0010] FIG. 3B shows an experimental arrangement for testing a membrane assembly.

[0011] FIG. 3C shows an experimental arrangement for testing a membrane assembly.

[0012] FIG. 4 shows an experimental arrangement for a membrane in which a solution follows a cross-flow path.

[0013] FIG 5A shows scanning electron microscopy (SEM) images of uncoated and graphene like carbon (GLC) coated MicroPES 12F membrane as shown the top row is at x 1000 magnification and the bottom row x5000 magnification.

[0014] FIG. 5B schematically shows the pore structures of GLC coated MicroPES 12F.

[0015] FIG. 5C schematically shows the pore structures of HSAG300 coated

MicroPES 12F.

[0016] FIG. 5D schematically shows the pore structures of KS75 or KS150 coated

MicroPES 12F.

[0017] FIG. 6 shows a collection SEM images of uncoated and GLC coated MicroPES

2F membrane the top row is at xlOOO magnification and the bottom row x5000 magnification.

[0018] FIG. 7 is a graph showing NaCl rejection performance of XLE and

HSAG300/XLE in the Sterlitech crossflow system. [0019] FIG. 8 is a graph showing MgSCE rejection performance of XLE and

HSAG300/XLE in the Sterlitech crossflow system.

[0020] FIG. 9A is a schematic diagram showing a sectional view of a spiral wound membrane construction.

[0021] FIG. 9B is an exploded view of the spiral membrane construction of FIG. 9A.

[0022] FIG. 10A is an SEM image of a MicroPES 2F membrane.

[0023] FIG. 10B is an SEM image of a GLC coated MicroPES 2F membrane.

[0024] FIG. 11 is a graph showing the filtration of municipal city water using electrically conducting GLC membranes with - IV electrical potential applied to the membrane.

[0025] FIG. 12 is a graph showing the filtration of city water using an electrically non conducting PAN-350 membrane with -IV electrical potential applied to the membrane.

[0026] FIG. 13 A is an SEM image of a PES substrate.

[0027] FIG. 13B is an SEM image of a membrane having GLC coated on PES.

[0028] FIG. 13C is an SEM image of a woven nylon substrate.

[0029] FIG. 13D is an SEM image of GLC coated on woven nylon.

[0030] FIG. 14A is an SEM image of a GLC/PES 2F substrate after bending.

[0031] FIG. 14B is an SEM image of a GLC/E F004 substrate after bending.

[0032] FIG. 14C is an SEM image of a GLC/PES 2F substrate after folding.

[0033] FIG. 14D is an SEM image of the GLC/PES 2F substrate of FIG. 14C with a box outlining the area where the substrate was folded.

[0034] FIG. 15 is a graph showing flow rate as a function of time for three membranes that have been folded or crumpled.

[0035] FIG. 16 is a graph showing the degradation of tetracycline.

[0036] FIG. 17 is a graph showing the reaction rate constant during the degradation of tetracycline.

[0037] FIG. 18 is a graph showing the concentration of tetracycline as a function of time during filtration.

[0038] FIG. 19 shows the result of a GLC/PES membrane tested in the cross-flow configuration to degrade tetracycline. DETAILED DESCRIPTION

[0039] Reference will now be made in detail to certain embodiments of the disclosed subject matter, examples of which are illustrated in part in the accompanying drawings. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

[0040] Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of“about 0.1% to about 5%” or“about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement“about X to Y” has the same meaning as“about X to about Y,” unless indicated otherwise. Likewise, the statement“about X, Y, or about Z” has the same meaning as“about X, about Y, or about Z,” unless indicated otherwise.

[0041] In this document, the terms“a,”“an,” or“the” are used to include one or more than one unless the context clearly dictates otherwise. The term“or” is used to refer to a nonexclusive“or” unless otherwise indicated. The statement“at least one of A and B” has the same meaning as“A, B, or A and B” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

[0042] In the methods described herein, the acts can be carried out in any order without departing from the principles of the disclosure, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0043] The term“about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range. [0044] The term“substantially” as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%.

[0045] Various embodiments described herein relate to membrane assemblies, methods of making membrane assemblies, and methods of using membrane assemblies. FIG. 1 is a sectional view of membrane assembly 100. As shown, membrane assembly 100 includes porous substrate 104, carbon nanolayer 102, and electrical contact area 106. Porous substrate 104 is a substrate that is capable of filtering a variety of particles. Porous substrate 104 includes porous substrate first surface 108 and opposed porous substrate second surface 110. Porous substrate first surface 108 and porous substrate second surface 110 are separated by thickness ti. Thickness ti can be any suitable value depending on the application. For example, thickness ti can be in a range of from about 1 pm to about 10 mm, about 5 pm to about 1 mm, about 10 pm to about 200 pm, less than, equal to, or greater than about 1 pm, 5 pm, 10 pm, 15 pm, 20 pm, 25 pm, 30 pm, 35 pm, 40 pm, 45 pm, 50 pm, 55 pm, 60 pm, 65 pm, 70 pm, 75 pm, 80 pm, 80 pm, 90 pm, 95 pm, 100 pm, 150 pm, 200 pm, 250 pm, 300 pm, 350 pm, 400 pm, 450 pm, 500 pm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or about 10 mm.

[0046] Porous substrate 104 includes a plurality of pores. One of more of the plurality of pores can be through pores that fully extend between porous substrate first surface 108 and porous substrate second surface 110. Alternatively, one of more of the plurality of pores may only extend through a portion of thickness ti. For example, one of more of the plurality of pores may extend from porous substrate first surface 108 to a point or location short of porous substrate second surface 110. Alternatively, one of more of the plurality of pores may extend from porous substrate second surface 110 to a point or location short of porous substrate first surface 108. Alternatively, in further embodiments, one or more of the plurality of pores may extend between two points located away from porous substrate first surface 108 and porous substrate second substrate 110. The overall porous structure formed by the pores can generally conform to a foam-like porous structure or a finger-like porous structure.

[0047] The average pore size of the plurality of pores can be any suitable value. For example, an average pore size can be in a range of from about 0.1 nm to about 10,000 nm, about 1 nm to about 1,000 nm, about 2 nm to about 500 nm, about 3 nm to about 100 nm, less than, equal to, or greater than about 0.1 nm, 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40 ,45, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, or about 2,000 nm. The average pore size can be characterized as the diameter or width of the individual pores. Generally, the average pore size determines what size of particle may or may not pass through an individual pore. For example, if a particle has a major dimension that is larger than an individual pore size, the particle may not be able enter the pore or pass completely through the pore. The porosity of porous substrate 104 can be measured by the percent of the total volume (vol %) of porous substrate 104 that is occupied by the pores. According to various embodiments, the porosity of porous substrate 104 can be in a range of from about 0 vol% to about 90 vol%, about 20 vol% to about 70 vol%, less than, equal to, or greater than about 0 vol%, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or about 90 vol%.

[0048] Porous substrate 104 can include many suitable materials. For example, porous substrate 104 can include a ceramic material, a polymeric material, a metal, a fabric, or a combination thereof. Examples of suitable ceramic materials include alumina, silica, ceria, a silicon nitride, a glass, an alumina-phosphorous pentoxide, an alumina-boria-silica, a zirconia, a zirconia-alumina, a zirconia-silica, a fused aluminum oxide, a heat-treated aluminum oxide, a ceramic aluminum oxide, a sintered aluminum oxide, a silicon carbide material, titanium diboride, boron carbide, tungsten carbide, titanium carbide, diamond, cubic boron nitride, garnet, fused alumina-zirconia, cerium oxide, zirconium oxide, titanium oxide, or a combination thereof. Examples of suitable polymeric materials include a polyester, a polypropylene, a polyethylene, a polystyrene, a polycarbonate, a polyimide, a polymethyl methacrylate, a polyvinyl chloride, a polytetrafluoroethylene, a cellulose acetate, a silicone, a rubber, a polyether sulfide, a polyethersulfone, a polyamide, copolymers thereof, or a combination thereof.

[0049] In embodiments, where the porous substrate includes a fabric, the fabric can be a nonwoven fabric, a woven fabric, a knitted fabric, or a combination thereof. The fabric can include a collection of fibers. Examples of suitable fibers include a vulcanized fiber, a staple fiber, a continuous fiber, or a combination thereof. The fibers can be the same length or can be present as a distribution of fibers having different lengths. According to various further embodiments, the fibers can be incorporated into a yarn that includes a plurality of fibers.

[0050] The choice of material or materials of porous substrate 104 can help to increase the strength, flexibility, or both of membrane assembly 100. It can be desirable to choose a flexible material to include in porous substrate 104, this is because the material or materials of carbon nanolayer 102 are sufficiently flexible. The flexibility of these materials can be helpful to allow the membrane assembly to be bent, creased, rolled, or folded and located in any number of substituents such as a pipe. [0051] As shown in FIG. 1, porous substrate 104 is a monolithic and single-layer structure. However, in further embodiments, porous substrate 104 can include a plurality of layers. In these multi-layer embodiments, it is possible for each layer or subset of layers to have substantially the same material. However, in further embodiments, it may be possible for each layer or for at least any subset of layers to include a different material. Additionally, according to various embodiments, different layers of porous substrate 104 can have different average pore sizes or each layer can have substantially the same average pore size.

[0052] As shown in FIG. 1, carbon nanolayer 102 is joined to porous substrate 104.

Carbon nanolayer 102 is directly joined to porous substrate and there is no binder deposited between carbon nanolayer 102 and porous substrate 104. The direct joining between carbon nanolayer 102 and porous substrate 104 can be a result of the process by which the carbon nanolayer is coated on porous substrate 104, which is described further herein. In embodiments where a binder is included, however, the binder can be at least partially or fully deposited on porous substrate first surface 108, first surface of carbon nanolayer 112, or both. In some embodiments, a binder is disposed between porous substrate 104 and carbon nanolayer 102. In examples where the binder is only partially deposited on porous substrate first surface 108, first surface of carbon nanolayer 112, or both, care can be taken to apply the binder such that pores in either carbon nanolayer 102, porous substrate 104, or both are not blocked. Where present, the binder may be a polymer. Examples of suitable binders include polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, poly(3,4-ethylenedioxythiophene)- poly(styrenesulfonate), copolymers thereof, or mixtures thereof.

[0053] Carbon nanolayer 102 includes carbon nanolayer first surface 112 and opposed carbon nanolayer second surface 114. An interface is formed between porous substrate first surface 108 and carbon nanolayer first surface 112. Carbon nanolayer first surface 112 and carbon nanolayer second surface 114 are separated by thickness h. Thickness h can be any suitable value depending on the application. For example, thickness h can be in a range of from about 5 nm to about 500 nm, about 7 nm to about 100 nm, about 10 nm to about 50 nm, less than, equal to, or greater than about 5 nm, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 ,65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160,

165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255,

260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 330, 340, 345, 350, 355, 360,

365, 370, 375, 380, 390, 395, 400, 405, 410, 415, 420, 425, 430, 435, 440, 445, 450, 455, 460,

465, 470, 475, 480, 485, 490, 495, or about 500 nm. [0054] As shown in FIG. 1, thickness t2 is less than thickness ti. According to various embodiments, thickness ti can be in a range of from about 1.1 to about 50 times greater than thickness t2, about 1.5 times to about 10 times, less than, equal to, or greater than about 1.1 times greater, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5,

12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21, 21.5,

22, 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, 31, 31.5,

32, 32.5, 33, 33.5, 34, 34.5, 35, 35.5, 36, 36.5, 37, 37.5, 38, 38.5, 39, 40, 40.5, 41, 41.5, 42,

42.5, 43, 43.5, 44, 44.5, 45, 45.5, 46, 46.5, 47, 47.5, 48, 48.5, 49, 49.5, or about 50 times greater. Although, thickness t2, as shown, is less than thickness ti, in alternative embodiments, thickness t2 can be equal to or greater than thickness ti. As shown, carbon nanolayer 102 has a substantially uniform thickness. However, in further embodiments, it may be possible for carbon nanolayer 102 to have a substantially variable thickness (e.g., the surface of carbon nanolayer 102 may have respective maximum and minimum values measured in the z- direction).

[0055] Carbon nanolayer 102 includes one or more graphite platelets at least partially embedded in nanocrystalline carbon. As used herein,“graphite platelet” refers to a graphitic carbon material having a first order laser Raman spectrum that exhibits two absorption bands including a sharp, intense band (G peak) centered at about 1570-1580 cm, and a broader, weak band (D peak) centered at about 1320-1360 cm. As used herein,“nano-crystalline carbon” refers to a graphitic carbon material having a first order laser Raman spectrum that exhibits two absorption bands including a pair of weak bands (G peaks) centered at about 1591 cm and 1619 cm, respectively, and a sharp, intense band (D peak) centered at about 1320-1360 cm.

[0056] Graphite platelets of carbon nanolayer 102 can have an average major dimension in a range of from about 1 pm to about 100 pm, about 20 pm to about 70 pm, less than, equal to, or greater than about 1 pm, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,

18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,

42, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67,

68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92,

93, 94, 95, 96, 97, 98, 99, or about 100 mih. According to various embodiments, the size of each graphite platelet is sustainably the same. However, in further embodiments, the graphite platelets may have a distribution of sizes such that about 5 wt% to about 99 wt% of the graphite platelets have substantially the same major dimension, about 10 wt% to about 80 wt%, about 15 wt% to about 50 wt%, less than, equal to, or greater than about 5 wt%, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or about 99 wt%. According to various embodiments, the major dimension of at least one graphite platelet is greater than an average pore size of the porous substrate. According to various further embodiments, the major dimension of about 5 wt% to about 100 wt% of the graphite platelets have a major dimension that is greater than the average pore size of porous layer 104, about 10 wt% to about 95 wt%, about 15 wt% to about 50 wt%, less than, equal to, or greater than about 5 wt%, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or about 99 wt%.

[0057] According to various embodiments, carbon nanolayer 102 can have a plurality of pores extending at least partially therethrough. One or more of the plurality of pores can be through pores that fully extend between first carbon nanolayer first surface 112 and carbon nanolayer second surface 114. Alternatively, one or more of the plurality of pores may only extend through a portion of thickness t2. For example, one or more of the plurality of pores may extend from carbon nanolayer first surface 112 to a point or location short of carbon nanolayer second surface 114. Alternatively, one or more of the plurality of pores may extend from carbon nanolayer second surface 114 to a point or location short of carbon nanolayer first surface 112. Alternatively, in further embodiments, one or more of the plurality of pores may extend between two points located away from carbon nanolayer first surface 112 and carbon nanolayer second substrate 114. The overall porous structure formed by the pores can generally conform to a foam-like porous structure or a finger-like porous structure.

[0058] Where present, an average pore size of individual pores of carbon nanolayer

102 can be in a range of from about 1 nm to about 50 nm, about 10 nm to about 30 nm, less than, equal to, or greater than about 1 nm, 5, 10, 15, 20, 25, 30, 35, 40, 45, or about 50 nm. The pores in carbon nanolayer 102 can account for any suitable vol% of carbon nanolayer 102. For example, the porosity of carbon nanolayer 102 can be in a range of from about 10 vol% to about 60 vol%, about 20 vol% to about 40 vol%, less than, equal to, or greater than about 10 vol%, 15, 20, 25, 30, 35, 40, 45, 50, 55, or about 60 vol%. According to various embodiments, the average pore size of the pores in porous substrate 104 can be substantially equivalent to the average pore size of the pores in carbon nanolayer 102. Moreover, the porosity by vol% in carbon nanolayer 102 and porous substrate 104 can be substantially the same. Alternatively, any one of the average pore size, porosity, or both can be substantially different between carbon nanolayer 102 and porous substrate 104.

[0059] As shown, carbon nanolayer 102 is a monolithic and single-layer structure.

However, in further embodiments, carbon nanolayer 102 can include a plurality of layers. The plurality of layers may be held together for example by a Van der Waals force. In these multi layer embodiments, it is possible for each layer or subset of layers to have substantially the same material. However, in further embodiments, it may be possible for each layer or for at least any subset of layers to include a different material. Additionally, according to various embodiments, different layers of carbon nanolayer 102 can have different average pore sizes or each layer can have substantially the same average pore size.

[0060] Carbon nanolayer 102 can be electrically conductive. The conductivity of carbon nanolayer 102 can be tuned to be any suitable value depending on a particular application. For example, a conductivity of the carbon nanolayer can be in a range of from about 5 W/square (e.g., W/mm ² , W/cm ² , W/m ² , or W/ίh ² ) ΐo about 10,000 W/square, about 500 W/square to about 2,000 W/square, about 1,000 W/square to about 1,500 W/square, less than, equal to, or greater than about 5 W/square, 500, 1,000, 1,500, 2,000, 2,500, 3,000, 3,500, 4,000, 4,500, 5,000, 5,500, 6,000, 6,500, 7,000, 7,500, 8,000, 8,500, 9,000, 9,500, or about W/square.

[0061] According to various embodiments, the conductivity of carbon nanolayer 102 can be controlled by altering the structure of carbon nanolayer 102 or by including additives therein. One example of an additive that can be included in carbon nanolayer 102 can include a dopant. Where present the dopant can be in a range from about 0.01 wt% to about 15 wt% of the carbon nanolayer, about 1 wt% to about 5 wt%, less than, equal to, or greater than about 0.01 wt%, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11,

11.5, 12, 12.5, 13, 13.5, 14, 14.5, or about 15 wt%. Examples of dopants can include boron, manganese, nitrogen, oxides thereof, or mixtures thereof. Where present a dopant can be used for modifying properties of carbon nanolayer 102 such as the electrical conductivity or thermal conductivity of the nanolayer. Even though an additive such as a dopant can be added to carbon nanolayer, it is also within the scope of this disclosure for carbon nanolayer 102 to be substantially free of any additives.

[0062] Carbon nanolayer 102 is adapted to receive electricity from a voltage source.

To transfer electricity to carbon nanolayer 102, electrical contact area 106 is disposed on carbon nanolayer 102. Electrical contact area 106 can include one or more electrical contact points. As shown in FIG. 1, electrical contact area 106 includes two electrical contact points located on opposite ends of carbon nanolayer second surface 114. In alternative configurations, any one or more components of electrical contact area 106 can be located on carbon nanolayer first surface 112. Electrical contact area 106 can include a conductive point, conductive plate, conductive strip, or the like. Electrical contact area 106 can include any suitable electrically conductive material, such as metal, including, for example, nickel (Ni), palladium (Pd), gold (Au), silver (Ag), copper (Cu), alloys thereof, or combinations thereof or a conducting polymer. [0063] Where present, the voltage source can be electrically coupled to electrical contact area 106. The voltage source can be adapted to create an AC voltage, a DC voltage, or both (e.g., can selectively create an AC voltage or a DC voltage). According to various embodiments, the source of electrical voltage can be adapted to create a potential in a range of from about 0.2V to about 30V, about 0.5V to about 5V, about 1 V to about 3V, less than, equal to, or greater than about 0.2V, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9,

9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19,

19.5, 20, 20.5, 21, 21.5, 22, 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29,

29.5, or about 30V. The voltage source can be powered by electrical connection to an outlet. In other embodiments, the voltage source can be connected to a battery, solar panel, fuel cell, or the like to increase the portability of membrane assembly 100.

[0064] Membrane assembly 100 can include any further components or features in addition to those described herein. For example, some embodiments of membrane assembly 100 can include an absorbent layer in contact with porous substrate 104, carbon nanolayer 102, or both. An absorbent layer can function to either absorb preselected materials before they pass at least partially or fully through membrane assembly 100. Alternatively, an absorbent layer can be positioned to absorb preselected materials that have passed at least partially or fully through membrane assembly 100. An absorbent layer can include many suitable materials. For example, an absorbent layer can include an activated carbon.

[0065] As shown in FIG. 1, membrane assembly 100 includes one carbon nanolayer

102 and one porous substrate 104. However, in further embodiments, it may be possible for membrane assembly to have multiple carbon nanolayers 102 or porous substrates 104. For example membrane assembly 100 could include two carbon nanolayers. In such an embodiment, the second carbon nanolayer 102 can be attached to porous substrate second surface 110.

[0066] Membrane assembly 100 can be configured to be one of many types of membranes. For example, membrane assembly 100, can be configured as a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, a reverse osmosis membrane, or a combination thereof. Designations such as microfiltration, ultrafiltration, and nanofiltration can designate the average pore size in membrane assembly 100 as being, for example, in the micro- or nano-scale. A reverse osmosis membrane can operate, for example, in situations where membrane assembly 100 is between two liquids one with a greater concentration of solids than the other. Typically, the liquid having a lower concentration of solids would flow across membrane assembly 100 to the liquid having a greater concentration of solids. However, a reverse osmosis membrane system is capable of applying pressure to drive liquid from the side of membrane assembly 100 having a greater concentration of solids to the side of membrane assembly 100 having a lower concentration of solids or no solids.

[0067] To filter a solution using membrane assembly 100, a solution can be contacted with membrane assembly 100. Specifically, the solution can be contacted with carbon nanolayer 102. The solution can include a distribution of solid particles or matter to be filtered or separated. The solid particles or matter that are filtered (e.g., not able to pass through membrane assembly 100) can be selected for by adjusting the average pore size in carbon nanolayer 102, porous substrate 104, or both. As an example, a major dimension of the particles filtered by membrane assembly can be in a range of from about 0.001 pm to about 10 pm, about 0.001 pm to about 0.1 pm, about 0.001 pm to about 0.01 pm, less than, equal to, or greater than about 0.001 pm, 0.005, 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070, 0.075, 0.080, 0.085, 0.090, 0.095, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.0, 1.1, 1.2,

1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4,

3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6,

5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8,

7.9, 8, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, or about 10 pm.

[0068] The particles or matter that are filtered can include organic particles, inorganic particles, biological particles or mixtures thereof. The particles or matter can be homogenously or heterogeneously dispersed in an aqueous medium (e.g., a medium or solvent including about 50 wt% to about 100 wt% water) or an organic medium (e.g., a medium or solvent including greater than 50 wt% to about 100 wt% organic material). Specific examples of particles or matter that can be filtered can include a pharmaceutical (e.g., an antibiotic), an aqueous salt, a sugar, a metallic ion, a pyrogen, a silica, a pigment, a natural organic matter, a protein, a virus, a bacteria, a cell, a synthetic polymer material, a polymer microparticle, or a combination thereof.

[0069] Examples of pharmaceuticals and antibiotics that can be filtered can include tetracycline. Tetracycline is a widely used antibiotic in which about 50 wt% to 80% of the dosage can be expelled into the environment after ingestion. Traces of tetracycline can be found in the environment for example through sewage (e.g., hospital sewage) this can lead to environmental contamination. Examples of other pharmaceuticals or antibiotics include bezafibrate, carbamazeprin, primidon, diazepam, ibuprofen, lopamidol, metformin, metoprolol, sotalol, and sulfamethoxazole. Examples of organic waste that may be filtered can include N, N-di ethyl-3 -methylbenzamide, atrazine, n-nitrosodimethylamine, tri(2-chloroethyl) phosphate, n-octylphenol, nonylphenol, metolachlor, triclosan, bisphenol-a, carbamaziapine, dehydroepiandrosterone, 17-P-estradiol, estrone, dihydrotestosterone, trans-testosterone, 17- ethynylestradiol, estriol, and progesterone.

[0070] Examples of bacteria that can be filtered include a gram-positive bacteria, a gram-negative bacteria, or a mixture thereof. In some embodiments, the bacteria can include Clostridium botulinum, Listeria monocytogenes, Acetic acid bacteria , Acidaminococcus, Acinetobacter baumannii, Agrobacterium tumefaciens, Akkermansia muciniphila, Anaerobiospirillum, Anaerolinea thermolimosa, Anaerolinea thermophila, Arcobacter, Arcobacter skirrowii, Armatimonas rosea, Azotobacter salinestris, Bacteroides, Bacteroides fragilis, Bacteroides ureolyticus, Bacteroidetes, Bartonella japonica, Bartonella koehlerae, Bartonella taylorii, Bdellovibrio, Brachyspira, Bradyrhizobium japonicum, Caldilinea aerophile, Cardiobacterium hominis, Chaperone-Usher fimbriae, Christensenella, Chthonomonas calidirosea, Coxiella burnetiid, Cyanobacteria, Cytophaga, Dehalogenimonas lykanthroporepellens, Desulfurobacterium atlanticum, Devosia pacifica, Devosia psychrophila, Devosia soli, Devosia subaequoris, Devosia submarina, Devosia yakushimensis, Dialister, Dictyoglomus thermophilum, Enterobacter, Enterobacter cloacae, Enterobacter cowanii, Enter obacteriaceae, Enterobacteriales, Escherichia, Escherichia coli, Escherichia fergusonii, Escherichia hermannii, Fimbriimonas ginsengisoli, Flavobacterium, Flavobacterium akiainvivens, Francisella novicida, Fusobacterium necrophorum, Fusobacterium nucleatum, Fusobacterium polymorphum, Haemophilus felis, Haemophilus haemolyticus, Haemophilus influenzae, Haemophilus pittmaniae, Helicobacter, Kingella kingae, Klebsiella pneumoniae, Kluyvera ascorbate, Kluyvera cryocrescens, Legionella, Legionella clemsonensis, Legionella pneumophila, Leptonema illini, Leptotrichia buccalis, Levilinea saccharolytica, Luteimonas aquatic, Luteimonas composti, Luteimonas lutimaris, Luteimonas marina, Luteimonas mephitis, Luteimonas vadose, Megamonas, Megasphaera, Meiothermus, Meiothermus timidus, Methylobacterium fujisawaense, Morax-Axenfeld diplobacilli, Moraxella, Moraxella bovis, Moraxella osloensis, Morganella morganii, Mycoplasma spumans, Neisseria cinereal, Neisseria gonorrhoeae, Neisseria meningitidis, Neisseria polysaccharea, Neisseria sicca, Nitrosomonas eutropha, Nitrosomonas halophila, Nonpathogenic organisms, OMPdb, Pectinatus, Pedobacter heparinus, Pelosinus, Propionispora, Proteobacteria, Proteus mirabilis, Proteus penneri, Pseudomonas, Pseudomonas aeruginosa, Pseudomonas luteola, Pseudoxanthomonas broegbernensis, Pseudoxanthomonas japonensis, Rickettsia, Salinibacter ruber, Salmonella, Salmonella bongori, Salmonella enterica, Samsonia, Selenomonadales, Serratia marcescens, Shigella, Shimwellia, Solobacterium moorei, Sorangium cellulosum, Sphaerotilus natans, Sphingomonas gei, Spirochaeta, Spirochaetaceae, Sporomusa, Stenotrophomonas, Stenotrophomonas nitritireducens, Thermotoga neapolitana, Thorselliaceae, Trimeric autotransporter adhesion, Vampirococcus, Verminephrobacter, Vibrio adaptatus, Vibrio azasii, Vibrio campbellii, Vibrio cholerae, Victivallis vadensis, Vitreoscilla, Wolbachia, Yersiniaceae, Zymophilus , strains thereof, or combinations thereof.

[0071] According to various embodiments, membrane assembly 100 can be helpful to prevent fouling or to make it easier to remove fouling using backwashing. For example, membrane assembly 100 can be helpful in preventing colloidal fouling, organic fouling, biofouling, scaling, or a combination thereof. One way that fouling is prevented is by applying voltage to carbon nanolayer 102. The voltage can be applied selectively or continuously using the voltage source. In some embodiments that voltage source may put an electric current through carbon nanolayer 102, but in other embodiments, a potential may be created across carbon nanolayer 102, but no current is applied through carbon nanolayer 102.

[0072] Applying the voltage to carbon nanolayer 102 can help to substantially prevent fouling in a variety of ways. For example, if a voltage is applied to carbon nanolayer 102, it can be possible to chemically transform any one of more of the particles or matter that comes into contact with carbon nanolayer 102. For example, any one or more of the particles or matter in the solution may be oxidizable or reducible. A specific example may include reducing tetracycline to a benign compound prior to filtration. Upon contact with carbon nanolayer 102, having a voltage applied thereto, the one or more particles or matter may be oxidized or reduced. This can result in the particle or matter potentially being cleaved or otherwise transformed into a particle or molecule that is not harmful and may be allowed to at least partially pass through membrane assembly 100. According to some embodiments, it may be possible to reduce the size of the particles or molecules to such a degree that they are less likely to clog the pores in carbon nanolayer 102, porous substrate 104, or both.

[0073] Another feature that can help to substantially reduce the degree of fouling in membrane assembly 100 is that a major dimension of a portion of the total number of graphite platelets is greater than the average pore size of the pores of porous substrate 104. This can be helpful to substantially reduce the risk that a graphite platelet that has broken loose from carbon nanolayer 102 would be able to penetrate and become lodged in a pore of porous substrate 104. This can also be helpful during a buffing process in which the graphite platelets are buffed to porous substrate 104. This is because the platelets will be too large to enter and clog the pores in porous substrate 104.

[0074] The ability of membrane assembly 100 to effectively filter a solution, while substantially preventing fouling, allows for membrane assembly 100 to be deployed and used effectively in a variety of environments and to be exposed to a variety of solutions. For example, membrane assembly 100 can be deployed in a water purification system. For example, membrane assembly 100 can be deployed in a municipal filtration or water purification system. Membrane assembly 100 can also be deployed in smaller scale filtration or water purification systems such as a residential or commercial filtration or water purification system. Examples of commercial applications in which membrane assembly 100 may be used include use in filtering agricultural waste (e.g., pesticide or animal manure waste), industrial plant sludges, food processing wastewater, hospital or clinical wastewater, municipal solid waste treatment plant organic fractions, industrial waste, municipal water, or a mixture thereof.

[0075] FIG. 2 shows a collection of views depicting a buff-coating process for forming carbon nanolayer 102 on porous substrate 104. In step 1.1 of this process, porous substrate 104 is provided. In step 1.2, a dry composition 200 is applied to porous substrate first surface 108. Dry composition 200 can include carbon particles and additional components such as polymeric microspheres and/or other microspheres. The carbon can be any form or type of carbon. Suitable carbons include conductive carbons such as graphite, carbon black, lamp black, or other conductive carbon materials. Typically, exfoliatable carbon particles, i.e., those that break up into flakes, scales, sheets, or layers upon application of shear force, are used. An example of useful exfoliatable carbon particles is HSAG300 graphite particles, available from Timcal Graphite and Carbon, Bodio, Switzerland. Other useful materials include but are not limited to SUPER P and ENSACO (also available from Timcal). The carbon particles can also be or comprise carbon nanotubes, including multi-walled carbon nanotubes. The carbon particles of composition 200 may have a Mohs hardness between 0.4 and 3.0 In connection with composition 200,“dry” means free or substantially free of liquid. Thus, composition 200 is provided in a solid particulate form, rather than in a liquid or paste form. The use of dry particles, rather than particles provided in a liquid or paste, may be beneficial in obtaining an optimal carbon nanolayer.

[0076] In step 1.3, mechanical buffing device 202 is used to lightly buff dry composition 200 against porous substrate first surface 108. An applicator pad of device 202 moves in a rapid orbital motion about a rotational axis 204 and presses lightly against surface porous substrate first surface 108, e.g., with a pressure normal to porous substrate first surface 108 greater than zero and less than about 30 g/cm. The orbiting applicator pad can also be moved in the plane of porous substrate 104 parallel to porous substrate first surface 108. Such in-plane motion of the applicator pad may be used to ensure complete buffing of the entire porous substrate first surface 108. In cases where porous substrate 104 is a web of material moving past buffing device 202, the orbiting applicator pad can thus be made to move in both cross-web and down-web directions.

[0077] The buffing motion can be a simple orbital motion or a random orbital motion.

A typical orbital motion is in the range of 50 to 10,000 revolutions per minute. Commercially available electric orbital sanders, such as the model B04900V Finishing Sander, marketed by Makita, Inc., Angio Japan, may be used as the buffing device 202. An applicator pad for such a device may be made of any appropriate material for applying particles to a surface. The applicator pad may, for example, be made of woven or non-woven fabric or cellulosic material. The applicator pad may alternatively be made of a closed cell or open cell foam material. In other cases, the applicator pad may be made of brushes or an array of nylon or polyurethane bristles. Whether the applicator pad comprises bristles, fabric, foam, and/or other structures, it typically has a topography in which particles of the dry composition can become lodged in and carried by the applicator pad. In this regard, dry composition 200 can be applied to porous substrate first surface 108 of porous substrate 104 in a number of ways.

[0078] In one approach, composition 200 can first be applied directly to porous substrate first surface 108, and then the applicator pad of buffing device 202 may contact composition 200 and porous substrate first surface 108. In another approach, composition 200 can first be applied to the applicator pad of buffing device 202, and the particle-loaded applicator pad may then contact the porous substrate first surface 108. In still another approach, a portion of composition 200 can be applied directly to porous substrate first surface 108, and another portion of the composition 200 can be applied to the applicator pad of buffing device 202, after which the particle-loaded applicator pad may contact porous substrate first surface 108 and remainder of composition 200.

[0079] The buffing operation of step 1.3 can be used to produce carbon nanolayer 102 directly on porous substrate first surface 108 of porous substrate 104, as shown in step 1.4. The thickness of carbon nanolayer 102 can be controlled by controlling the buffing time. Generally, the thickness of the coating increases linearly with buffing time after a certain rapid initial increase. Thus, the longer the buffing operation, the thicker the coating. The coating thickness of carbon nanolayer 102 can also be controlled by controlling the amount of dry powder composition 200 used during the buffing operation. Examples

[0080] Various embodiments of the present disclosure can be better understood by reference to the following Examples which are offered by way of illustration. The present disclosure is not limited to the Examples given herein. Unless otherwise noted or readily apparent from the context, all parts, percentages, ratios, etc. in the Examples and the rest of the specification are by weight.

Materials Used in the Examples

Test Methods

Surface resistivity measurement

[0081] The membrane sheet resistivity was measured using a RC2175 R-Check surface resistivity meter obtained from EDTM Inc, Toledo. OH.

Preparation of GLC coated membranes using Buff-coating process

[0082] An A4 sized filtration membrane was manually coated with GLC using a

SHUR-LINE™ Paint pad (obtained from Home Depot, Canada) that was attached to a Makita sander (model: B04900V finishing sander) obtained from Makita, Inc. Canada. First graphite powder was dispensed onto the membrane surface to be coated as evenly as possible, Then the sander with the pad was moved side-to-side with a frequency of ~ls per sweep to buff the surface with graphite powder. After the buffing step, which created the nanolayer of GLC on the membrane, , compressed air was applied to remove loose graphite particles off the coated membrane surface after buffing.

Permeability measurement of microfiltration membranes

[0083] The membrane permeability was tested using a 47 mm in-line filter holder from

Sterlitech, Kent, WA. Membranes were die-cut using a 47 mm circular die and then soaked in water for 5 minutes before it was placed in the filter holder. The inlet of the filter holder was connected to a 10 gallon pressured water tank that contained RO water. The membrane was conditioned under the testing pressure for 3 minutes and then permeate was collected each minute consecutively for 5 minutes for permeability calculation. The testing pressure for HSAG300 coated MicroPES 2F membrane was 30 psi and the other samples were tested at 10 psi.

Scanning electron microscope imaging

[0084] Membranes were examined using Hitachi’s FlexSEM 1000 available from

Hitachi, Tokyo Japan. The uncoated membranes were examined using a vapor pressure (VP) mode with a back scattered electron (BSE) detector, while the GLC coated membranes were examined under a high vacuum mode using a secondary electron (SE) detector.

Reverse osmosis (RO) membrane characterization using stirred cell

[0085] Sterlitech HP4750 stirred cells, obtained from Sterlitech, Kent, WA, were used to evaluate RO membrane performance. Membranes were first immersed in 50/50 w/w isopropyl alcohol/water solution for 3 minutes and then rinsed with water before being mounted into the stirred cell. The measurement was carried out under 80 psi. 250 mL 2000 ppm NaCl solution was used as the challenge solution. The stirring speed was 748 rpm. All membranes were conditioned at 80 psi for 5 minutes before measurements were taken. The first 10 mL solution was discarded and the next 20 mL solution was collected for electrical conductivity and permeability measurement. The ion reject rate is calculated using this equation: Ion rejection rate = 100% x (Cf - C _P ) / Cf, where Cf is the electrical conductivity of the challenge solution and C _P is the electrical conductivity of permeates.

RO membrane characterization using a cross-flow filtration system

[0086] A Sterlitech SEPA cell crossflow system, obtained from Sterlitech, Kent, WA, was utilized to characterize RO membranes. RO membranes were first immersed in 50/50 w/w isopropyl alcohol/water solution for 3 min and then rinsed with water before being mounted into the SEPA cells. Filtration was carried out at 22 °C with a concentrate flow rate of 1 L/min, a concentrate pressure of 5 bar, a Reynold number of 351 and a recovery rate between 0.5%- 1.0%. The feed solution was 2000 ppm NaCl or 2000 ppm MgSCri.

Ultra-Filtration (UF) membrane fouling test

[0087] To test the electrofiltration properties of GLC based membranes, an electrical filtration cell (Ecell) 300 was made that was modified from a Sterlitech crossflow SEPA cell, as shown in FIGs. 3 A-3C. As compared to a SEPA cell, the 4 posts and 2 O-rings were removed from the SEPA bottom plate 302 that was then laminated with a 3M Bumpon film, SJ5932, 304 available from 3M Company, St. Paul, MN, with a cut-out in the center to make a water channel 306. The Bumpon film acted as both an insulating film to electrically separate the two plates and a sealing film to prevent water leakage during filtration experiments. The conductive membrane 308 was edge-taped onto the top plate 310 using conductive tapes 312 (with a conductive adhesive). During electrofiltration, the two plates 302 and 310 were placed face-to- face and pressurized to -350 psi using a hydraulic press. A DC power source was then connected to these two plates separately to apply electrical potentials. The distance between the membrane and the other electrode surface was -2 mm.

[0088] Two pieces of same membrane were assembled in the control cell 314 (SEPA cell without modification) and the Ecell, respectively. Both membranes were conditioned at 80 psi for 5 hours using DI water in a dead-end mode before being exposed to city water (London Ontario, Canada) as the feed. The feed pressure was -22 psi. -1 volt electrical charge from a DC power was applied to the Ecell membrane, while no charge was applied to the control cell. The permeability of both cells were measured over 4-5 days. The metal ion concentration in water was tested using ion coupled plasma mass spectroscopy (ICPMS) according to EPA 200 8

Electro-oxidation test

[0089] An electrochemical cell, FIG. 4, utilizing two electrodes composed of stainless steel and a GLC filtration membrane were used. , FIG. 4 shows the electrode construction. Water containing TC flows through the cell in a cross-flow configuration, where redox reactions occur between the electrodes in a 3 mm gap. The performance of the filter was evaluated by measuring the concentration of TC not degraded by the cell that flows through the GLC/PES membrane as the permeate. The performance of GLC membranes in this setup was compared to similar electrochemical cells using carbon nanotubes as the active layer and quantified by calculating the electro-oxidation flux per gram (mol h ¹ m ² g ¹ ) of TC degraded by the membranes over time at a given voltage. GLC was shown to be effective at degrading TC and outperforms carbon nanotubes (CNTs) in terms of electro-oxidation efficiency. GLC membranes were shown to remove an equivalent concentration of TC compared to CNTs under the same flow rate conditions but can do so using a much thinner carbon film and a lower applied voltage. Electoroxidation Flux was calculated according to formula I:

(I)·

UV-Vis concentration measurements

[0090] The tetracycline concentration was measured using a Shimadzu UV-1800

UV/Visible Scanning Spectrophotometer, available from Shimadzu, Kyoto, Japan. The intensity of absorption peaks in the 250-400 nm range was used to represent the concentration of un-reacted tetracycline. Zero concentration was considered to be reached when the intensity of the peaks in this region is flat relative to the background.

Preparatory Examples

Oxidation of graphite by treating the graphite powder with KMn04

[0091] lOOg 3.16wt.% KMnCri solution was mixed with 2.1g of TIMCAL TIMREX®

HSAG300 graphite powder at room temperature, followed by adding 7.5 mL IN H2SO4. The resulting mixture was magnetically stirred for 4 hours. The resulting suspension was then vacuum filtrated and sufficiently washed with water. The collected powder was then dried in a 60 °C oven over night.

Examples

Ex.l Microfiltration Membranes

Characterization of GLC coated Microfiltration membranes based on MicroPES 12F

[0092] MicroPES 12F membranes were buff-coated on the airside (e.g., the side of the membrane roll that faces air and not the core) for 30 seconds using different graphites, see Table 1. The properties of GLC coated MicroPES 12F membranes are summarized in Table 1. The permeability of the coated membranes increases with increasing particle size. KS150 coated sample has the highest permeability, which is close to the uncoated membrane.

Table 1 : Properties of GLC coated MicroPES 12F membranes (air side)

[0093] The morphology of GLC coated MicroPES 12F membranes were studied using

SEM. FIG. 5 A (the top row shows magnification at 1000X and the bottom row shows magnification at 5000X)is an SEM micrograph of the airside of MicroPES 12 with and without GLC coating. The uncoated MicroPES 12F had a relatively smooth surface with a non-uniform surface pore distribution. The smooth surface provided a good template for GLC formation. The average surface pore size was around 3-10 microns, which accounted for high permeability of this membrane. KS6 coated MicroPES 12F showed a uniform GLC surface with majority of the surface pores covered. This is likely because the surface pores were first filled by KS6 particles and then covered with exfoliated graphite platelets as depicted in FIG. 5B, which led to a significant permeability reduction. HSAG300 coated MicroPES 12F showed some smaller surface pores that were clogged similar to KS6 coated membrane, while other large pores were only filled with graphite particles without graphite nanoplatelets covering on the surface, as illustrated in FIG. 5C. Both KS75 and KS150 coated MicroPES 12F membranes showed a similar surface morphology. The membrane surfaces were conformally coated with graphite nanoplatelets uniformly. Most surface pores were visible in SEM and little pore-filling by graphite particles was observed. This was because most KS75 and KS150 graphite particles are larger than the surface pores. Instead, some exfoliated platelets entered the pores due to their smaller sizes, as illustrated in FIG. 5D. The packing of these platelets in the pore structure was fairly loose and some pores were only partially covered by platelets on their surfaces. This open structure of both membranes likely accounted for the high membrane permeability.

Preparation and characterization of GLC coated Microfiltration membranes based on MicroPES 2F

[0094] MicroPES 2F was a microfiltration membrane that had pore sizes much smaller than that of MicroPES 12F and most of its surface pores were less than 1 micron. MicroPES 2F was coated on the airside with HSAG300, KS75 and KS150 for 30 seconds, respectively. Table 2 lists the electrical sheet resistivity and permeability of the uncoated MicroPES 2F and graphite coated ones. The resistivity followed this order: KS150 > HSAG300 > KS75. All coated membranes showed lower permeability than that of the uncoated MicroPES 2F. HSAG300 coated membrane showed the lowest permeability, >100x less than MicroPES 2F. The SEM image in FIG. 6 shows the coating with HSAG300 resulted in blocking most pores on surface with exfoliated platelets/GLC. Coating with KS75 and KS150 led to much thinner GLC coatings, which made the membrane surface pore structures visible under SEM after coating, as shown in FIG. 6 (the top row shows magnification at 1000X and the bottom row shows magnification at 5000X). Due to small surface pores of MicroPES 2F, some pores were partially or fully covered by exfoliated platelets, while other pores were completely open, indicated by the bright spots in SEM that were a result of discharging due to the lack of GLC coverage under the SE mode. The uncovered surface pore structure of KS75 and KS 150 renders a high membrane permeability. Table 2: Properties of GLC coated MicroPES 2F membranes (airside)

Ex. 2 Reverse Osmosis Membranes

Preparation and characterization of GLC coated reverse osmosis membranes

[0095] XLE membranes were buff-coated with HSAG300, KS6, KS75 and KS150 for

30 seconds respectively. The membrane permeability and ion rejection data in Table 3 and Table 4 were measured using a Sterlitech HP4750 stirred cell. 2000 ppm NaCl solution was used as the challenge.

Table 3 : Electrical and Filtration Data of GLC Coated XLE

Membranes with 30 second Coating Time

[0096] In order to improve the performance of graphite coated XLE membranes,

HSAG300 coating with less coating time was carried out. 5 second and 10 second coating time gave improved results in NaCl rejection that are closer to that of uncoated XLE membrane, shown in Table 4. XLE membrane was also manually coated by moving the graphite saturated pad gently on membrane surface for 10 seconds. This was to reduce vertical pressure on membrane surface exerted by the sander weight to reduce surface change during buffing. The results were very close to that of the uncoated XLE.

Table 4: Coating Time Effect on Membrane Performance

[0097] The performance of 10 second coated HSAG300/XLE membrane for NaCl rejection was further evaluated in a Sterlitech SEP A cell crossflow system. As shown in FIG. 7, the HSAG300/XLE membrane started with a higher permeability and lower NaCl rejection than that of the XLE membrane. Its permeability continued to decrease accompanied by the increasing NaCl rejection. After ~20 hours, the permeability and rejection rate became stable. This dynamic change was attributed to membrane conditioning. The XLE membrane (comparative sample) also showed a sign of conditioning but the process was much faster than the HSAG300/XLE membrane. After the conditioning time, the NaCl rejection rate of HSAG300/XLE membrane reached -90% with a permeability of 4.6 LMH/bar.

[0098] To test the membrane’ s ability to rej ect divalent ions, 2000 ppm MgSCri solution was used as the feed, following the NaCl rejection experiment. As shown in FIG. 8, both XLE (comparative example) and HSAG300/XLE membranes showed a stable performance. The HSAG300/XLE membrane showed a high rejection rate of 98.6% with a permeability of 5.6 LMH/bar.

Ex. 3. Spirally wound electrically conductive membranes

Design of spiral wound element for electrically conductive membranes

[0099] Various examples of an RO filtration membrane units can be constructed by spirally winding a membrane with two spacer meshes as described in standard texts. For example, see Nanofiltration: Principals and Applications (by Anthony Gordon Fane I, A Schaefer, T David Waite and Anthony G Fane, , 2005, Elsevier Science (ISBN- 13:9781856174053) page 74, Figure 3, the contents of which are hereby incorporated by reference. Electrically conducting membranes can be used in a similar spiral-wound configuration. One possible option of such an article is shown in FIGs. 9A and 9B. The design of electro-filtration element shown in FIGs. 9A and 9B has two conductive membranes 400 consisting a conductive GLC layer 402 and a supporting layer 404. The two conductive surfaces 402 facing each other and are separated by a feed spacer 406. The two supporting layers are separated by a permeate spacer 408. Two thin electrical conductor strips 410 were laminated along the edges of the conductive membranes and were connected to an electrical power source 412 that resided outside of the spiral wound element. This ensured that the electrical potential was evenly distributed along the length of the conductive membranes. The two membranes could be charged periodically or continuously depending on applications and operation requirements and always had opposite polarities. It was preferable to apply alternating potential to the conductive membranes, which was shown to have favorable antifouling effect, especially for biofouling reduction.

Ex. 4. Fouling resistance of GLC coated ultrafiltration membranes

[00100] The conductive GLC membranes were made by buff-coating Timrex HSAG300 onto the airside of MicroPES 2F membrane for 30 seconds. FIGs. 10A and 10B show the SEM images of the MicroPES 2F and GLC coated membrane surfaces.

[00101] The GLC coated membranes were soaked in water for about 3 minutes and then installed in both the control cell and the Ecell. As shown in FIG. 11, the Ecell and control cell membranes showed different permeability profiles. Permeability reduction of the control cell membrane showed a similar trend as that in FIG. 12 (comparative example) with a fast reduction in the first 20 hours of filtration and then the permeability reduction rate decreased significantly, which suggested a close-to-saturation state. The Ecell membrane showed almost no permeability reduction in the first 20 hours and then the permeability started to decline very slowly afterwards. The difference in the permeability change of the Ecell and control membranes suggested that much less fouling occurred to the electrically charged Ecell membrane, which could be explained by electrostatic repulsion between the negatively charged membrane surface and foulants (NOMs and nanoparticles) with the same charge.

[00102] To understand the impact of electrofiltration on the permeate water quality, metal ion analysis on the permeates from both Ecell and control cell was carried out. The ion concentrations of 5 metals (Fe, Cr, Ni, Mo and Mn) common in stainless steel were measured and were summarized in Table 5. There was no significant ion concentration difference between the Ecell and control cell permeates, which suggested that there was no significant adverse leaching of metal ions into water and therefore the water quality is not impacted by applying -IV electrical potential to the Ecell membrane.

Table 5: Metal ion concentrations in the permeates of both control cell and Ecell

Comparative Examples

CE.1 Fouling resistance of ultrafiltration PAN-350 membranes

[00103] Two PAN-350 membranes were assembled in the control cell and the Ecell, respectively. A -1 volt electrical charge from a DC power was applied to the Ecell, while no charge was applied to the control cell. The permeability of both cells was measured over 4-5 days. The Ecell membrane showed a slightly lower starting flux. This is a result of less active membrane surface area in the Ecell because of the presence of a stainless steel mesh. Significant permeability reduction happened in the first 30 hours of city water filtration with a similar rate for both membranes. The permeability reduction continued with a much reduced rate after 30 hours. The permeability reduction was attributed to membrane fouling. It is known that natural organic matters (NOMs) exist in city water. NOMs are a mixture of soluble polymers with a wide range of molecular weights and functionalities. Because of small pore sizes of UF membranes, absorption of NOMs within UF membrane pores significantly reduced the channel size for water passage, resulting in a reduce permeability over time. The similar fouling rates of the control and Ecell membranes suggested that electrically charged Ecell alone without conductive membranes does not have a positive effect on fouling mitigation.

Ex. 5. Mechanical Robust Conductive Membranes

[00104] Scanning electron microscopy (LEO Zeiss 1540XB, SEM) was used to investigate the surface morphology before and after bending/folding of GLC coated membranes. The GLC membrane was relatively brittle compared to the porous substrate and showed surface cracks after manipulation that were not present in pristine as-prepared samples. Even though surface cracks can be introduced by physical manipulation of the membranes, they do not affect the flow rate or electrical characteristics of the membranes. Electrically conductive GLC membranes prepared with buff coating method on porous polyether sulfone (PES 2F) and woven nylon (EF004) substrates were resistant to physical manipulation from bending, folding, or crumpling.

[00105] FIGS. 13A-13D show SEM images of GLC membranes composed of HSAG300 with a 90s coating time deposited on PES (pore size ~0.5-1.0 pm) and woven nylon (pore size -400 nm) substrates immediately after preparation with no additional treatment. FIGS 13A and 13C are the uncoated PES and woven nylon substrates, respectively, and FIGS 13B and ID are the coated PES and woven nylon substrates, respectively. The as prepared membranes showed some loose particles on the surface as well as small cracks that are microns in length. Bending and folding of these membranes was performed in two ways: 1) bending the membrane around a wooden dowel with a 2 cm diameter more than ten times, 2) folding and crumpling the membrane with 180° bends such that the entire surface experiences some folding. FIGs. 14A-14D shows SEM images after physical manipulation of GLC. In all cases cracks were evident on the surface that are much larger/longer than seen is as prepared membranes. However, although cracks were evident after manipulation, the films remained continuous and did not show an increase in resistivity. Before manipulation the typical resistivity is 500-2000 W/square was measured, and it remained unchanged after manipulation. Resistivity was measured using the Surface Resistivity Measurement test..

[00106] FIG. 15 shows the flow rate of folded/crumpled GLC membranes prepared from HSAG300 with a 90s coating time, comparing the PES and nylon substrates, as well as GLC prepared using HSAG300 that has undergone an oxidizing pre-treatment. Flow rate experiments were carried out on 14.6 cm ² membranes in a 316-stainless steel stirred cell (Steriltech HP4750). From FIG. 15, it was observed that the flow rate decreased over a time scale of several hours, to ultimately settle at a constant value of approximately 7 LMH/bar for all three membranes. This behavior was typical of all types of GLC membranes on porous substrate regardless of how they are manipulated, including as-prepared membranes.

[00107] The final flow rate of as-prepared membranes compared to crumpled membranes after water conditioning is shown in Table 6. The flow rates of as-prepared and crumpled membranes were in good agreement for all samples tested. From these results, it was concluded that GLC membranes were very resistant to physical folding and crumpling, and maintain their electrical and flow rate characteristics after physical manipulation. Table 6: Flow rates (LMH/bar) of as-prepared and

after folding GLC coated membranes after conditioning

Ex. 6. Electro-oxidation of tetracycline

[00108] Using the architecture shown in FIG. 4, two sets of electro-oxidation experiments were conducted; (1) in a beaker using stirring at 390 rpm with no applied pressure to the membrane, (2) in a cross-flow cell with water pressure of 22 PSI applied to the membrane using a commercial Sterlitech Cross-Flow system. In both cases a solution containing 0.2 mM of tetracycline (TC) and 10 mM of Na2SC>4 was used as the challenge solution. Na2SC>4 acts as an electrolyte during the electro-oxidation process to improve the water conductivity. The test was carried out according the“Electro-oxidation test” previously described.

[00109] FIG. 16 shows the concentration of TC over time in case (1) with GLC/steel cell placed in a beaker with TC solution and stirred, using +1.0 V applied to the GLC membrane prepared from HSAG300 on MicroPES 2F with a 60s coating time. After approximately 30 mins, the concentration of undegraded TC in the solution approaches zero. Degradation of TC was seen visually through a change in color of the solution from the pale yellow of pure TC to a deep brown color of the reaction products. FIG. 17 shows the reaction rate constant determined from the concentration decrease, indicating a first order reaction rate constant. This meant that the reaction depended on the concentration of only one reactant as expected, but also indicated that no side reactions were occurring.

[00110] Further experiments were conducted in a cross-flow configuration with the membrane under pressure at 22 PSI. This result captured the effect of absorption on the filter, which was not seen in the stirring experiment of FIG. 17 because the membranes were too tight to allow for significant permeate without applied pressure. As a control experiment to observe the effect of absorption and applied voltage, an insulating polyacrylonitrile (PAN) ultrafiltration membrane with similar pore size (200 nm) to GLC/PES was tested in the cross flow configuration. FIG. 18 shows the concentration of TC in solution as a function of time using the PAN membrane, with and without and applied voltage. From FIG. 18, the PAN membranes do not filter a significant amount of TC (5-10%), with or without a voltage applied to the membrane. This indicated that side reactions in the filtration cell were not responsible for removal of TC, and that a conductive membrane is required as the counter electrode to steel for electro-oxidation to take place.

[00111] FIG. 19 shows the result of a GLC/PES membrane tested in the cross-flow configuration to degrade TC. The graph showed both concentration of TC expressed as a percentage (open squares), and the flow rate through the membrane (open diamonds), which remained relatively constant at 1.4 mL/min. Before the voltage was applied to membrane at ~45 minutes, a reduction in TC concentration in the permeate of approximately 40%, due to absorption to the GLC surface, was observed. This was confirmed by the flow rate which showed a linear decrease during this time period. When the voltage was applied, there was a brief period where the TC concentration in the permeate was unchanged it is believed that this was caused by degradation of TC already absorbed to the filter. After 15 minutes of applied voltage, the TC concentration began to decrease rapidly and approached a minimum of 5% after 80 mins of applied voltage. After the initial stage when voltage is applied, the cell was operated for extended periods of time without a change in in TC degradation performance or a decrease in flow rate due to fouling.

[00112] With respect to electro-oxidation, the performance of a GLC was compared to CNTs in Table 7. The GLC was prepared according to the protocol described previously in the section titled“Preparation of GLC coated membranes using Buff-coating process.” The unit describing the energy cost to degrade TC was electro-oxidation flux per gram. GLC showed electro-oxidation flux per gram 3 times greater than that of CNTs with 95% of TC degraded, while also operating at a lower voltage of 1.0 V compared to 2.5 V for the CNT based device. It was not necessary to operate at higher voltage for electro-oxidation to occur with GLC, but the reaction rate will be faster is higher voltage are used. This result showed that GLC based ultrafiltration membranes can be used in an electrochemical cell to efficiently degrade aqueous small molecule contaminants such as tetracycline using low operating voltages compared to state-of-the-art devices in the literature.

Table 7: Electro-oxidation performance of GLC compared to CNTs to degrade tetracycline.

Ex. 7. Electrooxidation of other pharmaceutical compounds

[00113] The following pharmaceutical compounds were tested as in Example 6 in place of tetracycline, and was found to be decomposed with electro-oxidation:

DicloFenac - CAS 15307-79-6;

Progesterone - CAS 57-83-0; and

Acetominophen - CAS 103-90-2.

[00114] The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the embodiments of the present disclosure. Thus, it should be understood that although the present disclosure has been specifically disclosed by specific embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those of ordinary skill in the art, and that such modifications and variations are considered to be within the scope of embodiments of the present disclosure.

Additional Embodiments.

[00115] The following exemplary embodiments are provided, the numbering of which is not to be construed as designating levels of importance:

[00116] Embodiment 1 provides a membrane comprising:

a porous substrate;

a carbon nanolayer disposed on the porous substrate, the carbon nanolayer comprising graphite platelets at least partially embedded in nanocrystalline carbon; and an electrical contact area disposed on the carbon nanolayer.

[00117] Embodiment 2 provides the membrane of Embodiment 1, wherein the porous substrate comprises a plurality of pores having an average pore size in a range of from about 0.1 nm to about 10,000 nm.

[00118] Embodiment 3 provides the membrane of any one of Embodiments 1 or 2, wherein the porous substrate comprises a plurality of pores having an average pore size in a range of from about 3 nm to about 100 nm.

[00119] Embodiment 4 provides the membrane of any one of Embodiments 1-3, wherein the membrane further comprises a voltage source electronically coupled to the electrical contact area.

[00120] Embodiment 5 provides the membrane of any one of Embodiments 1-4, wherein the electrical contact area comprises a plurality of electrical contact points.

[00121] Embodiment 6 provides the membrane of any one of Embodiments 1-5, wherein the porous substrate comprises a ceramic material, a polymeric material, a metal, a fabric, or a combination thereof.

[00122] Embodiment 7 provides the membrane of Embodiment 6, wherein the ceramic material comprises alumina, silica, ceria, a silicon nitride, a glass, an alumina-phosphorous pentoxide, an alumina-boria-silica, a zirconia, a zirconia-alumina, a zirconia-silica, a fused aluminum oxide, a heat-treated aluminum oxide, a ceramic aluminum oxide, a sintered aluminum oxide, a silicon carbide material, titanium diboride, boron carbide, tungsten carbide, titanium carbide, diamond, cubic boron nitride, garnet, fused alumina-zirconia, cerium oxide, zirconium oxide, titanium oxide, or a combination thereof.

[00123] Embodiment 8 provides the membrane of any one of Embodiments 6 or 7, wherein the polymeric material comprises a polyester, a polypropylene, a polyethylene, a polystyrene, a polycarbonate, a polyimide, a polymethyl methacrylate, a polyvinyl chloride, a polytetrafluoroethylene, a cellulose acetate, a silicone, a rubber, a polyether sulfide, a polyethersulfone, a polyamide, copolymers thereof, or a combination thereof.

[00124] Embodiment 9 provides the membrane of any one of Embodiments 6-8, wherein the fabric is a nonwoven fabric, a woven fabric, a knitted fabric, or a combination thereof.

[00125] Embodiment 10 provides the membrane of any one of Embodiments 6-9, wherein the fabric comprises a vulcanized fiber, a staple fiber, a continuous fiber, or a combination thereof.

[00126] Embodiment 11 provides the membrane of any one of Embodiments 1-10, wherein a thickness of the porous substrate is in a range of from about 1 pm to about 10 mm. [00127] Embodiment 12 provides the membrane of any one of Embodiments 1-11, wherein a thickness of the porous substrate is in a range of from about 10 pm to about 200 pm.

[00128] Embodiment 13 provides the membrane of any one of Embodiments 1-12, wherein a thickness of the porous substrate is greater than a thickness of the carbon nanolayer.

[00129] Embodiment 14 provides the membrane of any one of Embodiments 1-13, wherein the porous substrate comprises a plurality of layers.

[00130] Embodiment 15 provides the membrane of any one of Embodiments 1-14, wherein the porous substrate comprises a single layer.

[00131] Embodiment 16 provides the membrane of any one of Embodiments 1-15, wherein the pore size of the individual pores or the porous substrate are substantially the same.

[00132] Embodiment 17 provides the membrane of any one of Embodiments 1-16, wherein a porosity of the porous substrate is in a range of from about 0 vol% to about 90 vol% of the porous substrate.

[00133] Embodiment 18 provides the membrane of any one of Embodiments 1-17, wherein a porosity of the porous substrate is in a range of from about 20 vol% to about 70 vol% of the porous substrate.

[00134] Embodiment 19 provides the membrane of any one of Embodiments 1-18, wherein the carbon nanolayer has a thickness in a range of from about 5 nm to about 500 nm.

[00135] Embodiment 20 provides the membrane of any one of Embodiments 1-19, wherein the carbon nanolayer has a thickness in a range of from about 10 nm to about 50 nm.

[00136] Embodiment 21 provides the membrane of any one of Embodiments 1-20, wherein the carbon nanolayer comprises a dopant.

[00137] Embodiment 22 provides the membrane of Embodiment 21, wherein the dopant ranges from about 0.01 wt% to about 15 wt% of the carbon nanolayer.

[00138] Embodiment 23 provides the membrane of any one of Embodiments 21 or 22, wherein the dopant ranges from about 1 wt% to about 5 wt% of the carbon nanolayer.

[00139] Embodiment 24 provides the membrane of any one of Embodiments 21-23, wherein the dopant comprises boron, manganese, oxides thereof, or mixtures thereof.

[00140] Embodiment 25 provides the membrane of any one of Embodiments 1-24, wherein the carbon nanolayer comprises one or more layers.

[00141] Embodiment 26 provides the membrane of any one of Embodiments 1-25, wherein the carbon nanolayer has a substantially uniform thickness.

[00142] Embodiment 27 provides the membrane of any one of Embodiments 1-26, wherein a thickness of the carbon nanolayer is variable. [00143] Embodiment 28 provides the membrane of any one of Embodiments 1-27, wherein the carbon nanolayer comprises a plurality of pores individually having a having an average pore size in a range of from about 1 nm to about 50 nm.

[00144] Embodiment 29 provides the membrane of any one of Embodiments 1-28, wherein the carbon nanolayer comprises a plurality of pores having an average pore size major diameter in a range of from about 10 nm to about 30 nm.

[00145] Embodiment 30 provides the membrane of any one of Embodiments 1-29, wherein a porosity of the carbon nanolayer is in a range of from about 10 vol% to about 60 vol% of the carbon nanolayer.

[00146] Embodiment 31 provides the membrane of any one of Embodiments 1-30, wherein a porosity of the carbon nanolayer is in a range of from about 20 vol% to about 40 vol% of the carbon nanolayer.

[00147] Embodiment 32 provides the membrane of any one of Embodiments 1-31, wherein a major dimension of the graphite platelets, individually, is in a range of from about 1 pm to about 100 pm.

[00148] Embodiment 33 provides the membrane of any one of Embodiments 1-32, wherein a major dimension of individual graphite platelets is in a range of from about 20 pm to about 70 pm.

[00149] Embodiment 34 provides the membrane of any one of Embodiments 1-33, wherein a major dimension of the individual graphite platelets is greater than an average pore size of the porous substrate.

[00150] Embodiment 35 provides the membrane of any one of Embodiments 1-34, wherein the membrane is free of a binder between the porous substrate and the carbon nanolayer.

[00151] Embodiment 36 provides the membrane of any one of Embodiments 1-35, wherein the porous substrate and the carbon nanolayer are in direct contact.

[00152] Embodiment 37 provides the membrane of any one of Embodiments 1-36, further comprising a binder disposed between the porous substrate and the carbon nanolayer.

[00153] Embodiment 38 provides the membrane of Embodiment 37, wherein the binder comprises polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), copolymers thereof, or mixtures thereof.

[00154] Embodiment 39 provides the membrane of any one of Embodiments 1-38, wherein the carbon nanolayer is a first carbon nanolayer disposed on a first surface of the porous substrate and the membrane further comprises a second carbon nanolayer disposed on a second surface of the porous substrate.

[00155] Embodiment 40 provides the membrane of any one of Embodiments 4-39, wherein the voltage source is adapted to create an AC voltage, a DC voltage, or both.

[00156] Embodiment 41 provides the membrane of any one of Embodiments 1-40, wherein the source of electrical voltage is adapted to create a potential in a range of from about 0.2V to about 30V.

[00157] Embodiment 42 provides the membrane of any one of Embodiments 1-41, wherein the source of electrical voltage is adapted to create a potential in a range of from about 0.5V to about 5V.

[00158] Embodiment 43 provides the membrane of any one of Embodiments 1-42, wherein the source of electrical voltage is electrically connected to an outlet, a battery, a solar panel, or a combination thereof.

[00159] Embodiment 44 provides the membrane of any one of Embodiments 1-43, further comprising an absorbent layer in contact with the porous substrate, the carbon nanolayer, or both.

[00160] Embodiment 45 provides the membrane of Embodiment 44, wherein the absorbent layer comprises an activated carbon.

[00161] Embodiment 46 provides the membrane of any one of Embodiments 1-45, wherein a conductivity of the carbon nanolayer is in a range of from about 5 W/square to about 10,000 W/square.

[00162] Embodiment 47 provides the membrane of any one of Embodiments 1-46, wherein a conductivity of the carbon nanolayer is in a range of from about 500 W/square to about 2,000 W/square.

[00163] Embodiment 48 provides the membrane of any one of Embodiments 1-47, wherein the membrane is a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, a reverse osmosis membrane, or a combination thereof.

[00164] Embodiment 49 provides the membrane of any one of Embodiments 1-48, wherein the membrane is capable of filtering particles having a major dimension in a range of from about 0.001 pm to about 10 pm.

[00165] Embodiment 50 provides the membrane of any one of Embodiments 1-49, wherein the membrane is capable of filtering particles individually having a major dimension in a range of from about 0.001 pm to about 0.1 pm. [00166] Embodiment 51 provides the membrane of any one of Embodiments 1-50, wherein the membrane is capable of filtering particles individually having a major dimension in a range of from about 0.001 pm to about 0.01 pm.

[00167] Embodiment 52 provides the membrane of any one of Embodiments 1-51, wherein at least a portion of the pores are through pores.

[00168] Embodiment 53 provides a membrane comprising:

a porous substrate comprising a ceramic material, a polymeric material, a metal, a fabric, or a combination thereof;

a carbon nanolayer disposed on the porous substrate, the carbon nanolayer comprising graphite platelets at least partially embedded in nanocrystalline carbon, wherein a major dimension of the graphite platelets, individually, is greater than an average pore size of an individual pore of the porous substrate and the porous substrate and the carbon nanolayer directly contact one another; and

an electronic contact area adapted to receive electrical voltage from a source coupled to the electrical contact area, the source of electrical voltage adapted to create an AC voltage, a DC voltage, or both.

[00169] Embodiment 54 provides a method of making the membrane of any one of Embodiments 1-53, the method comprising:

at least partially coating a surface of the porous substrate with a composition of carbon particles; and

buffing the carbon particles on the substrate at a force normal to the surface of the porous substrate.

[00170] Embodiment 55 provides the method of Embodiment 54, wherein the buffing comprises moving an applicator pad in a plane substantially parallel to the surface of the porous substrate, with the force normal to the surface of the porous substrate.

[00171] Embodiment 56 provides the method of Embodiment 55, wherein the applicator pad is moved in a plurality of directions relative to a point on the surface of the porous substrate.

[00172] Embodiment 57 provides the method of any one of Embodiments 55 or 56, wherein the applicator pad moves in an orbital fashion substantially parallel to the surface of the porous substrate.

[00173] Embodiment 58 provides the method of any one of Embodiments 54-57, wherein at least a portion of the carbon particles are graphite.

[00174] Embodiment 59 provides the method of any one of Embodiments 54-58, wherein the carbon particles are platelets. [00175] Embodiment 60 provides the method of any one of Embodiments 54-59, further comprising contacting the porous substrate with buffing aid particles, exfoliating particles, or a mixture thereof.

[00176] Embodiment 61 provides the method of Embodiment 60, wherein the buffing aid particles have a low affinity for the substrate to be coated.

[00177] Embodiment 62 provides a method of filtering a solution, the method comprising:

contacting a solution with the membrane of any one of Embodiments 1-53 or formed according to the method of any one of Embodiments 54-61, such that at least a portion of the solution passes through the membrane.

[00178] Embodiment 63 provides the method of Embodiment 62, wherein the solution comprises a plurality of particles.

[00179] Embodiment 64 provides the method of Embodiment 63, wherein at least some of the particles are solid.

[00180] Embodiment 65 provides the method of any one of Embodiments, 63 or 64, wherein the particles comprise organic particles, inorganic particles, or a combination thereof.

[00181] Embodiment 66 provides the method of any one of Embodiments 63-65, wherein the solution comprises an antibiotic, an aqueous salt, a sugar, a metallic ion, a pyrogen, a silica, a pigment, a natural organic matter, a protein, a virus, a bacteria, a synthetic polymer material, a polymer microparticle, or a combination thereof.

[00182] Embodiment 67 provides the method of Embodiment 66, wherein the antibiotic is tetracycline.

[00183] Embodiment 68 provides the method of any one of Embodiments 63-67, wherein the particles comprise biological particles.

[00184] Embodiment 69 provides the method of Embodiment 68, wherein the biological particles comprise a bacteria, a virus, a protein, a cell, or a mixture thereof.

[00185] Embodiment 70 provides the method of any one of Embodiments 62-69, wherein the solution comprises an oxidizable or reducible molecule.

[00186] Embodiment 71 provides the method of any one of Embodiments 62 or 70, wherein a major dimension of at least some of the particles of the solution is larger than a major dimension of at least some of the pores of the porous layer.

[00187] Embodiment 72 provides the method of any one of Embodiments 62-71, further comprising applying pressure to the solution and the membrane. [00188] Embodiment 73 provides the method of any one of Embodiments 62-72, further comprising connecting the carbon nanolayer to a source of electrical voltage.

[00189] Embodiment 74 provides the method of any one of Embodiments 62-73, further comprising applying a voltage to the membrane.

[00190] Embodiment 75 provides the method of Embodiment 74, wherein the electrical voltage is continuously applied to the membrane.

[00191] Embodiment 76 provides the method of Embodiment 74, wherein the electrical voltage is selectively applied to the membrane.

[00192] Embodiment 77 provides the method of any one of Embodiments 74-76, wherein applying the electrical voltage to the membrane substantially reduces fouling of the membrane as compared to a corresponding membrane that is free of having an electrical voltage applied thereto, free of the carbon nanolayer structure, or both.

[00193] Embodiment 78 provides the method of Embodiment 77, wherein the fouling comprises, colloidal fouling, organic fouling, biofouling, scaling, or a combination thereof.

[00194] Embodiment 79 provides the method of any one of Embodiments 74-78, wherein applying the voltage to the membrane chemically transforms at least one component of the solution.

[00195] Embodiment 80 provides the method of any one of Embodiments 74-79, wherein applying the voltage to the membrane oxidizes or reduces at least one component of the solution.

[00196] Embodiment 81 provides the method of any one of Embodiments 62-80, wherein the solution is an aqueous solution, an organic solution, or a mixture thereof.

[00197] Embodiment 82 provides the method of Embodiment 81, wherein the solution comprises animal manure, wastewater treatment plant sludge, food processing wastewater, municipal solid waste treatment plant organic fractions, industrial waste, municipal water, or a mixture thereof.