TECHNICAL FIELD

[0001] The present disclosure relates to graphene aerogel adsorbents, and particularly relates to graphene aerogel adsorbents for metal pollutants removal. More particularly, the present disclosure relates to a method for fabricating a graphene aerogel adsorbent by three dimensional printing of a graphene aerogel adsorbent.

BACKGROUND

[0002] Adsorption is considered a simple and effective method for separating metal ions from water and wastewater. Activated carbon is one of the most commonly used adsorbents that may be utilized for adsorbing metal ions from water and wastewater. However, activated carbon may have disadvantages including high contamination during production, low mechanical strength, not capable of being regenerated and reused, and a relatively low adsorption rate. One approach to address the disadvantages of activated carbon is to utilize 3D graphene adsorbents or graphene aerogels instead of activated carbon. Graphene aerogels may exhibit high porosity, low density, and higher adsorption rates due to their strong 3D structure, in which pore dimensions may be adjustable.

[0003] One common approach for synthesizing graphene aerogels is to reduce a graphene oxide solution to form graphene hydrogel. Then, the graphene hydrogel is subjected to a freeze-drying process, where the solvent is replaced by air within the pores and a network of bonded graphene sheets surrounding air pockets may be obtained. 3D printing methods may be utilized for controlling the morphology of graphene aerogels. In a common 3D printing method, graphene oxide ink may be extruded into isooctane and may be subsequently freeze dried to remove the solvent and form a 3D lattice of graphene aerogel. Graphene oxide ink that may be utilized in 3D printing methods may be obtained by gelling graphene oxide in a viscous solution with addition of silica to reduce viscosity and thereby allow for the graphene oxide ink to be extrudable from a nozzle or in other words to be printable.

[0004] There is a need for improved systems and methods for three dimensional printing of graphene oxide inks to fabricate graphene aerogels adsorbents. There is further a need for developing a system and method for three dimensional printing of graphene oxide inks that may allow for a better control over the porosity of the resulting graphene aerogels adsorbents. SUMMARY

[0005] This summary is intended to provide an overview of the subject matter of the present disclosure and is not intended to identify essential elements or key elements of the subject matter, nor is it intended to be used to determine the scope of the claimed implementations. The proper scope of the present disclosure may be ascertained from the claims set forth below in view of the detailed description and the drawings.

[0006] According to one or more exemplary embodiments, the present disclosure is directed to a three-dimensional printing system for fabricating an aerographene adsorbent. An exemplary system may include an inkjet printhead that may be configured to print a graphene ink composition with a predetermined pattern onto a substrate. An exemplary inkjet printhead may include a plurality of nozzles that may be configured to spurt out the graphene ink composition in jets onto the substrate.

[0007] An exemplary system for fabricating an aerographene adsorbent may further include a cooling mechanism that may be configured to freeze the graphene ink composition on the substrate. An exemplary frozen graphene ink may then be transferred to a freeze dryer to be freeze dried and form an exemplary aerographene adsorbent. An exemplary graphene ink composition may include an aqueous solution of graphene with a concentration in a range of 1 to 5 g/L and a viscosity in a range of 1 to 5 mPa.s. In an exemplary embodiment, an exemplary graphene ink may further include a 0.05 to 0.5 wt.% of Triton XIOOrange as an additive.

[0008] In an exemplary embodiment, an exemplary cooling mechanism of an exemplary system for fabricating an aerographene adsorbent may be configured to freeze the graphene ink composition down to a temperature in a range of -30 °C to -35 °C.

[0009] An exemplary system for fabricating an aerographene adsorbent may further include a mounting mechanism comprising three mutually perpendicular linear translational degrees of freedom, the inkjet printhead and the substrate mat be mounted on the mounting mechanism, and the mounting mechanism may be configured to move the inkjet printhead and the substrate relative to each other utilizing the three mutually perpendicular linear translational degrees of freedom.

[0010] An exemplary system for fabricating an aerographene adsorbent may further include an ink supply mechanism that may include a graphene ink reservoir. An exemplary graphene ink reservoir may be connected in fluid communication with the inkjet printhead. An exemplary ink supply mechanism may be configured to supply the graphene ink to the inkjet printhead.

[0011] In an exemplary embodiment, an exemplary cooling mechanism may include a thermoelectrical cooling element. An exemplary substrate may be in direct contact with the thermoelectrical cooling element.

[0012] An exemplary system for fabricating an aerographene adsorbent may further include a control unit. An exemplary control unit may be connected in signal communication with the inkjet printhead and the mounting mechanism. An exemplary control unit may include at least one processor, and at least one memory that may be coupled to the at least one processor. At least one exemplary memory may be configured to store executable instructions to urge the processor to receive the predetermined pattern from the at least one memory, and urge the inkjet printhead to print the graphene ink composition layer-by-leyer with the predetermined pattern onto the substrate by urging the mounting mechanism to move the inkjet printhead and the substrate relative to each other based on at least the received predetermined pattern, and further by urging the inkjet printhead to eject graphene ink drops from the plurality of nozzles.

[0013] An exemplary mounting mechanism may further include a first linear actuator that may be coupled to the inkjet printhead, where the first linear actuator may be configured to actuate a linear translational motion of the inkjet printhead relative to the substrate along a first axis. An exemplary mounting mechanism may further include a second linear actuator that may be coupled to the first linear actuator, where the second linear actuator may be configured to actuate a linear translational motion of the first linear actuator relative to the substrate along a second axis. An exemplary mounting mechanism may further include a third linear actuator that may be coupled to the substrate, where the third linear actuator may be configured to actuate a linear translational motion of the substrate relative to the inkjet printhead along a third axis. In an exemplary embodiment, the first axis, the second axis, and the third axis are mutually perpendicular.

[0014] In an exemplary embodiment, the substrate may include a flat surface, where the first axis and the second axis may be parallel with a plane of the substrate and the third axis may be perpendicular to the plane of the substrate. [0015] In an exemplary embodiment, the inkjet printhead may further include an ink reservoir that may be connected in fluid communication with the plurality of nozzles, and ejection elements that may be coupled to the ink reservoir. Exemplary ejection elements may be configured to force the graphene ink drops out of the plurality of nozzles.

[0016] In an exemplary embodiment, the inkjet printhead may include a drop-on-demand thermal bubble inkjet printhead, where the ejection elements may include heating resistor ejection elements disposed within the ink reservoir. Exemplary heating resistor ejection elements may be configured to create bubbles within the graphene ink by vaporizing the graphene ink.

[0017] In an exemplary embodiment, the inkjet printhead may include a drop-on-demand inkjet printhead, where the ejection elements may include piezoelectric actuators associated with corresponding nozzles of the plurality of nozzles. Exemplary piezoelectric actuators may be configured to generate pressure pulses within the ink reservoir to force ink drops out of the plurality of nozzles.

[0018] In an exemplary embodiment, exemplary nozzles may include a plurality of elongated micrometric channels that may be formed in a nozzle plate. Exemplary elongated micrometric channels may be in fluid communication with the ink reservoir. In an exemplary embodiment, exemplary elongated micrometric channels may be arranged in arrays.

[0019] In an exemplary embodiment, cooling mechanism may further include a heat sink that may be coupled to the thermoelectrical cooling element, where a first side of the thermoelectrical cooling element may be in direct contact with the substrate, and an opposing second side of the thermoelectrical cooling element may be in contact with the heat sink within 0 °C water.

[0020] According to one or more exemplary embodiments, the present disclosure is directed to a 3D printing method for fabricating an aerographene adsorbent. An exemplary method may include applying a graphene ink to a substrate by printing the graphene ink layer-by- layer with a predetermined pattern onto the substrate. Printing the graphene ink may be performed utilizing a printing system that may include an inkjet printhead. An exemplary inkjet printhead may include a plurality of nozzles spurting out the graphene ink in jets. An exemplary method may further include freezing the applied graphene ink on the substrate. In an exemplary embodiment, frozen ink may then be transferred to a freeze drier to freeze dry the frozen ink and thereby form an exemplary aerographene adsorbent. [0021] In an exemplary embodiment, applying the graphene ink to the substrate may include layer-by-layer printing of a graphene ink composition onto the substrate, where an exemplary graphene ink composition may include an aqueous solution of graphene with a concentration in a range of 1 to 5 g/L and a viscosity in a range of 1 to 5 mPa.s. In an exemplary embodiment, an exemplary graphene ink may further include a 0.05 to 0.5 wt.% of Triton XIOOrange as an additive.

[0022] In an exemplary embodiment, applying the graphene ink to the substrate may include layer-by-layer printing of the graphene ink with the predetermined pattern onto the substrate utilizing the printing system, where an exemplary printing system may further include a mounting mechanism to allow the inkjet printhead and the substrate to be mounted on the mounting mechanism, the mounting mechanism including three mutually perpendicular linear translational degrees of freedom, the mounting mechanism further configured to move the inkjet printhead and the substrate relative to each other utilizing the three mutually perpendicular linear translational degrees of freedom.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The novel features which are believed to be characteristic of the present disclosure, as to its structure, organization, use and method of operation, together with further objectives and advantages thereof, will be better understood from the following drawings in which a presently exemplary embodiment of the present disclosure will now be illustrated by way of example. It is expressly understood, however, that the drawings are for illustration and description only and are not intended as a definition of the limits of the present disclosure. Embodiments of the present disclosure will now be described by way of example in association with the accompanying drawings in which:

[0024] FIG. 1 illustrates a printing system for fabricating an aerographene adsorbent, consistent with one or more exemplary embodiments of the present disclosure;

[0025] FIG. 2A illustrates a perspective view of a printing apparatus for fabricating an aerographene adsorbent, consistent with one or more exemplary embodiments of the present disclosure;

[0026] FIG. 2B illustrates a side view of a printing apparatus for fabricating an aerographene adsorbent, consistent with one or more exemplary embodiments of the present disclosure; [0027] FIG. 3 illustrates a scanning electron microscope (SEM) image of an exemplary fabricated aerographene adsorbent, consistent with one or more exemplary embodiments of the present disclosure; and

[0028] FIG. 4 illustrates an adsorption versus time diagram, consistent with one or more exemplary embodiments of the present disclosure.

DETAILED DESCRIPTION

[0029] The novel features which are believed to be characteristic of the present disclosure, as its structure, organization, use and method of operation, together with further objectives and advantages thereof, will be better understood from the following discussion.

[0030] The present disclosure is directed to exemplary embodiments of a three dimensional (3D) printing device for fabricating graphene aerogel adsorbents. An exemplary 3D printing device may include a printing cartridge that may be mounted on a cartridge moving assembly. An exemplary cartridge moving assembly may be configured to move an exemplary printing cartridge along two perpendicular axes. An exemplary printing cartridge may include an inkjet printhead that may be connected in fluid communication with a graphene ink reservoir. An exemplary inkjet printhead may include a plurality of nozzles that may be configured to drop an exemplary graphene ink composition onto a substrate. An exemplary 3D printing device may further include a cooling mechanism that may be coupled to an exemplary substrate. An exemplary cooling mechanism may be configured to freeze an exemplary printed pattern of an exemplary graphene ink composition on an exemplary substrate. In an exemplary embodiment, to form three-dimensional printed patterns of graphene aerogel, the frozen ink may be transferred to a freeze drier to be freeze dried.

[0031] An exemplary inkjet printhead may allow for 3D printing graphene aerogel on an exemplary substrate with controlled porosity and a relatively high precision due to utilizing exemplary micrometric nozzles for discharging an exemplary graphene ink onto an exemplary substrate. Such utilization of an inkjet printhead comprising a plurality of exemplary nozzles may allow for a better control over the pore structure of an exemplary fabricated graphene aerogel. An exemplary inkjet printhead may allow for fabricating mesoporous graphene aerogels with adjusted pore dimensions and distribution that enhances the adsorption capacity of an exemplary fabricated graphene aerogel by utilizing an exemplary 3D printing system. [0032] An exemplary 3D printing system for fabricating graphene aerogels may allow for fabricating an efficient adsorbent for adsorbing metal impurities, where an exemplary 3D printing system may allow for controlling the porosity of an exemplary fabricated adsorbent, ensuring the repeatability of the fabrication process of an exemplary fabricated adsorbent, and achieving a high precision (up to 1200x1200 dpi) for printing an exemplary fabricated adsorbent.

[0033] FIG. 1 illustrates a printing system 100 for fabricating an aerographene adsorbent, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, printing system 100 may include an integrated inkjet printhead cartridge 102, a mounting mechanism 104, a cooling mechanism 106, a control unit 108, and a power supply that may be coupled to printing system 100 to provide power to various electrical components of printing system 100. For simplicity, the power supply is not illustrated.

[0034] In an exemplary embodiment, inkjet printhead cartridge 102 may include an ink reservoir 110 that may be connected in fluid communication with an inkjet printhead 112. In an exemplary embodiment, inkjet printhead 112 may include a fluid ejection device that may include a plurality of nozzles 114. In an exemplary embodiment, inkjet printhead 112 may be configured to receive an ink composition from ink reservoir 110 and eject drops of an exemplary ink composition through plurality of nozzles 114 on a substrate 116 so as to print an exemplary ink composition onto substrate 116.

[0035] In an exemplary embodiment, cooling mechanism 106 may be coupled to substrate 116 and may be configured to reduce the temperature of substrate 116. In an exemplary embodiment, an exemplary ink composition deposited onto substrate 116 by utilizing inkjet printhead 112 may be frozen on substrate 116 by freezing an exemplary deposited ink composition. To this end, in an exemplary embodiment, cooling mechanism 106 may be configured to reduce the temperature of substrate 116 down to a temperature below the freezing point of an exemplary ink composition. For example, ink reservoir 110 may store a graphene ink composition and inkjet printhead 112 may be configured to receive an exemplary graphene ink composition from ink reservoir 110 and print an exemplary graphene composition with a predetermined pattern onto substrate 116. Then, cooling mechanism 106 may be configured to reduce the temperature of substrate 116 down to a temperature in a range of -30 °C to -35 °C below the freezing point of an exemplary graphene ink composition. This way, an exemplary printed graphene ink on substrate 116 may be frozen and consequently a frozen graphene ink pattern may be formed layer by layer on substrate 116.

[0036] In an exemplary embodiment, mounting mechanism 104 may include three mutually perpendicular linear translational degrees of freedom. In an exemplary embodiment, inkjet printhead cartridge 102 and substrate 116 may be mounted on mounting mechanism 104. In an exemplary embodiment, mounting mechanism 104 may be configured to move inkjet printhead cartridge 102 and substrate 116 relative to each other utilizing the three mutually perpendicular linear translational degrees of freedom. In an exemplary embodiment, such relative movement of inkjet printhead cartridge 102 and substrate 116 may allow for inkjet printhead 112 to print an exemplary graphene composition with a predetermined pattern onto substrate 116. In an exemplary embodiments, the three mutually perpendicular linear translational degrees of freedom of mounting mechanism 104 may include two translational degrees of freedom that may allow for inkjet printhead cartridge 102 to be moveable on a plane parallel with a plane of substrate 116 and a vertical translational degree of freedom that may allow for substrate 116 to be moveable along a normal axis of substrate 116. As used herein, a normal axis of an object may refer to an axis perpendicular to a plane of that object.

[0037] In an exemplary embodiment, printing system 100 may be configured as a scanning type printing system that may include one printhead, such as inkjet printhead cartridge 102 that must be moved relative to a print zone, such as surface of substrate 116 to scan the entire print zone. To this end, in an exemplary embodiment, mounting mechanism 104 may further include a carriage that may be configured to allow inkjet printhead cartridge 102 to be mounted on mounting mechanism 104. Then, mounting mechanism 104 may be configured to move inkjet printhead cartridge 102 relative to substrate 116 by moving the carriage utilizing the three mutually perpendicular linear translational degrees of freedom of mounting mechanism 104.

[0038] In an exemplary embodiment, inkjet printhead 112 may include either a drop-on- demand thermal bubble inkjet printhead or a piezoelectric inkjet printhead that may be configured to force an exemplary graphene ink composition out of plurality of nozzles 114 of inkjet printhead 112. In an exemplary embodiment, an exemplary drop-on-demand thermal bubble inkjet printhead may include heating resistor ejection elements that may be disposed within ink reservoir 110. Exemplary heating resistor elements may be configured to force an exemplary graphene ink drops out of plurality of nozzles 114 by creating bubbles within an exemplary ink composition. In an exemplary embodiment, heating resistor elements may be configured to heat up and vaporize a portion of an ink composition in response to receiving an electrical signal. In an exemplary embodiment, created bubbles may create the required force to spurt out graphene ink drops out of plurality of nozzles 114. In an exemplary embodiment, an exemplary piezoelectric inkjet printhead may include a piezoelectric actuator made of a piezoelectric material. In an exemplary embodiment, piezoelectric actuator may be configured to generate pressure pulses that may force graphene ink drops out of plurality of nozzles 114.

[0039] In an exemplary embodiment, plurality of nozzles 114 may include a plurality of elongated micrometric channels formed in a nozzle plate, where the plurality of elongated micrometric channels may be in fluid communication with ink reservoir 110. In an exemplary embodiment, plurality of nozzles 114 may be arranged as arrays of elongated micrometric channels.

[0040] In an exemplary embodiment, control unit 108 may include at least one processor, such as processor 118 that may be coupled to at least one memory, such as memory 120. In an exemplary embodiment, memory 120 may be configured to store executable instructions to urge processor 118 to receive an exemplary predetermined pattern from memory 120 and urge inkjet printhead 112 to print an exemplary graphene ink composition with the received predetermined pattern onto substrate 116. To this end, memory 120 may be configured to store executable instructions to urge processor 118 to command mounting mechanism 104 to move inkjet printhead 112 and substrate 116 relative to each other based on at least the received predetermined pattern, and further by urging inkjet printhead 112 to eject graphene ink drops from plurality of nozzles 114.

[0041] In an exemplary embodiment, cooling mechanism 106 may include a thermoelectrical cooling element 122 that may be placed in direct contact with substrate 116. In an exemplary embodiment, thermoelectrical cooling element 122 may include a solid-state heat pump that may transfer heat from a first side 124 of thermoelectrical cooling element 122 to an opposing second side 126 of thermoelectric al cooling element 122 depending on the direction of electrical current passing through of thermoelectrical cooling element 122. In an exemplary embodiment, responsive to applying an electrical current to of thermoelectric al cooling element 122, the temperature of first side 124 of thermoelectric al cooling element 122, which is in direct contact with substrate 116 may drop down to a temperature in a range of -30°C to -35°C. Since substrate 116 is in direct contact with first side 124 of thermoelectrical cooling element 122, the temperature of substrate 116 may drop down to a temperature in a range of -30°C to -35°C, as well.

[0042] In an exemplary embodiment, cooling mechanism 106 may further include a heatsink 128 that may be coupled to second side 126 of thermoelectrical cooling element 122. In an exemplary embodiment, heatsink 128 may be placed within an ice-and-water bath at 0 °C. In an exemplary embodiment, inkjet printhead 112 may be configured to receive an exemplary graphene ink composition from ink reservoir 110 and print an exemplary graphene composition with a predetermined pattern directly on first side 124 of thermoelectric al cooling element 122. Here, first side 124 of thermoelectrical cooling element 122 may function as substrate 116.

[0043] FIG. 2A illustrates a perspective view of a printing apparatus 200 for fabricating an aerographene adsorbent, consistent with one or more exemplary embodiments of the present disclosure. FIG. 2B illustrates a side view of printing apparatus 200 for fabricating an aerographene adsorbent, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, printing apparatus 200 may be structurally similar to printing system 100.

[0044] In an exemplary embodiment, printing apparatus 200 may include an integrated inkjet printhead cartridge 202 structurally similar to integrated inkjet printhead cartridge 102, a mounting mechanism 204 similar to mounting mechanism 104, a cooling mechanism 206 similar to cooling mechanism 106, a control unit similar to control unit 108, and a power supply that may be coupled to printing apparatus 200 to provide power to various electrical components of printing apparatus 200. For simplicity, the power supply unit and the control unit are not illustrated.

[0045] In an exemplary embodiment, mounting mechanism 204 may include three mutually perpendicular linear translational degrees of freedom similar to mounting mechanism 104. In an exemplary embodiment, inkjet printhead cartridge 202 and a substrate 216 similar to substrate 116 may both be mounted on mounting mechanism 204. In an exemplary embodiment, mounting mechanism 204 may be configured to move inkjet printhead cartridge 202 and substrate 216 relative to each other utilizing the three mutually perpendicular linear translational degrees of freedom. In an exemplary embodiment, such relative movement of inkjet printhead cartridge 202 and substrate 216 may allow for inkjet printhead cartridge 202 to print an exemplary graphene composition with a predetermined pattern onto substrate 216.

[0046] In an exemplary embodiment, the three mutually perpendicular linear translational degrees of freedom of mounting mechanism 204 may include two translational degrees of freedom that may allow for inkjet printhead cartridge 202 to be moveable on a plane parallel with a plane of substrate 216 and a vertical translational degree of freedom that may allow for substrate 216 and cooling mechanism 206 to be moveable along a normal axis of substrate 216 relative to inkjet printhead cartridge 202. An exemplary coordinate system may be defined, such as coordinate system 218 that include three mutually perpendicular axes of x, y, and z- In an exemplary embodiment, the two translational degrees of freedom that may allow for inkjet printhead cartridge 202 to be moveable on a plane parallel with a plane of substrate 216 may be along x and y axes. In an exemplary embodiment, the vertical translational degree of freedom that may allow for substrate 216 and cooling mechanism 206 to be moveable along a normal axis of substrate 216 relative to inkjet printhead cartridge 202 may be along z axis.

[0047] In an exemplary embodiment, mounting mechanism 204 may include a first linear actuator 220 that may be coupled to inkjet printhead cartridge 202 to actuate a linear translational motion of inkjet printhead cartridge 202 relative to substrate 216 along a first axis, such as x axis. In an exemplary embodiment, first linear actuator 220 may include an elongated mount 226, a first elongated guide shaft 228, a first linear bearing 230, and a linear actuation mechanism 232 coupled to first linear bearing 230. In an exemplary embodiment, linear actuation mechanism 232 may include a first rotary actuator such as an electric motor (not illustrated for simplicity) that may be coupled to a belt-and-pulley mechanism 234. In an exemplary embodiment, belt-and-pulley mechanism may convert a rotational motion of the rotary actuator to a linear motion of first linear bearing 230. In an exemplary embodiment, first linear bearing 230 may be moveably mounted on first guide shaft 228 and may be moveable along the first axis (x axis) on first guide shaft 228. In an exemplary embodiment, first guide shaft 228 may be attached to elongated mount 226 and inkjet printhead cartridge 202 may be mounted onto first guide shaft 228 utilizing first linear bearing 230. In an exemplary embodiment, back and forth linear movement of first linear bearing 230 on first guide shaft 228, which is actuated by linear actuation mechanism 232, may lead to back and forth linear movement of inkjet printhead cartridge 202 on first guide shaft 228 along the first axis (x axis).

[0048] In an exemplary embodiment, mounting mechanism 204 may further include a second linear actuator 222 that may be coupled to first linear actuator 220 to actuate a linear translational motion of first linear actuator 220 relative to substrate 216 along a second axis, such as y axis. In an exemplary embodiment, second linear actuator 222 may include two parallel guide shafts (236a and 2366) that may be mounted on a chassis 238. In an exemplary embodiment, parallel guide shafts (236a and 236/?) may be extended parallel to each other along the second axis ( axis) on both sides of elongated mount 226 such that elongated mount 226 may be moveably mounted on parallel guide shafts (236a and 2366) by utilizing linear bearings, such as a short linear bearing 240a and a long linear bearing 240/;. In other words, elongated mount 226 may be moveable along y axis on parallel guide shafts (236a and 2366). In an exemplary embodiment, second linear actuator 222 may further include at least one rotary actuator, such as electric motors (252a and/or 2526) with electromagnetic clutches that may be coupled to long linear 240Z> by a belt-and-pulley mechanism (not illustrated for simplicity), where the least one rotary actuator may be configured to actuate a linear motion of elongated mount 226 along y axis. Consequently, second linear actuator 222 may be configured to move inkjet printhead cartridge 202 along y axis relative to substrate 216 due to inkjet printhead cartridge 202 being mounted on elongated mount 226.

[0049] In an exemplary embodiment, mounting mechanism 204 may further include a third linear actuator 224 that may be coupled to substrate 216 to actuate a linear translational motion of substrate 216 relative to inkjet printhead cartridge 202 along a third axis, such as z axis. As mentioned before, the first axis, the second axis, and the third axis may be mutually perpendicular and may form a coordinate system similar to coordinate system 218. In an exemplary embodiment, third linear actuator 224 may include a moving platform 242 that may be configured to allow for cooling mechanism 206 to be mounted on moving platform 242. In an exemplary embodiment, third linear actuator 224 may further include a lead screw 244 that may be coupled to moving platform 242 and may be configured to drive a linear translational motion of moving platform 242 along z axis relative to inkjet printhead cartridge 202. To this end, third linear actuator 224 may further include parallel guide shafts (248a and 2486) that may be coupled to both sides of moving platform 242 utilizing linear bearings (250a and 250Z>). In an exemplary embodiment, cooling mechanism 206 and substrate may be moveable with moving platform 242 along z axis. In an exemplary embodiment, lead screw 244 may be coupled to a rotary actuator 246 and may be configured to translate the rotational motion of rotary actuator 246 into linear motion of moving platform 242 along z axis. In an exemplary embodiment, rotary actuator 246 may include a stepper motor.

[0050] In an exemplary embodiment, an exemplary method for fabricating an aerographene adsorbent may include applying a graphene ink to a substrate by printing the graphene ink with a predetermined pattern onto the substrate and then freezing the applied graphene ink. In an exemplary embodiment, to form an exemplary aerographene adsorbent with an exemplary predetermined pattern, the frozen ink may be transferred to a freeze dryer to be freeze dried. To this end, an exemplary printing system such as printing system 100 or a printing apparatus similar to printing apparatus 200 may be utilized.

EXAMPLE

[0051] In this example, a printing system similar to printing system 100 and printing apparatus 200 was utilized to fabricate an exemplary aerographene adsorbent and then the fabricated aerographene adsorbent was utilized for copper adsorption.

[0052] FIG. 3 illustrates a scanning electron microscope (SEM) image of the fabricated aerographene adsorbent, consistent with one or more exemplary embodiments of the present disclosure. As evident in FIG. 3, the fabricated aerographene adsorbent has a porous structure.

[0053] In this example, copper sulfate pentahydrate (CuSCU SfLO) salt is used for making an aqueous solution. To this end, the salt is dissolved in distilled water such that copper ions may have a concentration of 300 mgL ¹ within the solution. Then, a number of samples may be prepared by transferring the prepared solution into a number of vials, where 20 mL of the prepared solution is transferred into each vial. The sample vials are placed within an incubator and 1 g of the fabricated aerographene adsorbent may be added per liter of the prepared solution to each sample vial. The sample vials are mixed at 150 rpm but for different durations for each sample vial. In this example, sample vials were mixed for various durations of 1, 2, 3, 4, 6, 8, and 16 hours for the adsorption process occur in each vial. Here, the vials are kept at 25 °C during adsorption. After the adsorption process for the predetermined periods indicated above for each vial, adsorbents may be separated from solutions by a Buchner funnel. For comparison, the concentration of copper ions within each solution is analyzed by ICP analysis. [0054] FIG. 4 illustrates an adsorption versus time diagram, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIG. 4, the maximum amount of adsorption after 4 hours is 165 mg of copper per gram of aerographene adsorbent, which amounts to 95 percent of the copper within the samples. To achieve this amount of adsorption with activated carbon as adsorbent, 24 hours is required.

[0055] The remaining adsorbent on the Buchner funnel are added to 20 mL of a 0.1 M hydrochloric acid solution and by stirring the mixture at 250 °C at 150 rpm for 24 hours in an incubator, the adsorbed copper ion is released into the solution. Then, utilizing a Buchner funnel, the adsorbent is separated from the solution and the concentration of the copper ion is measured within the solution. The yield of this process is approximately 99 percent, which shows that the fabricated aerographene adsorbent may be utilized several times.

[0056] The embodiments have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0100] The foregoing description of the specific embodiments will so fully reveal the general nature of the disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance.

[0101] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments but should be defined only in accordance with the following claims and their equivalents.

[0102] Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not to the exclusion of any other integer or step or group of integers or steps. Moreover, the word "substantially" when used with an adjective or adverb is intended to enhance the scope of the particular characteristic, e.g., substantially planar is intended to mean planar, nearly planar and/or exhibiting characteristics associated with a planar element. Further use of relative terms such as “vertical”, “horizontal”, “up”, “down”, and “side-to- side” are used in a relative sense to the normal orientation of the apparatus.