Technical Field

The present invention generally relates to a composition useful in oil recovery operations.

Background Art

Crude oil is a vital source of energy for the world and makes a major contribution to the world economy.

Conventional oil production strategies have followed primary depletion, secondary recovery and tertiary recovery processes. During the primary depletion stage, reservoir drive uses a number of natural mechanisms to displace oil from porous rocks. Recovery factor during the primary recovery stage may average 5-20%. At some point, there will be insufficient underground pressure to force oil to the surface. Secondary recovery methods are then applied wherein the oil is subjected to immiscible displacement with injected fluids such as water or gas. Typical recovery factor after primary and secondary oil recovery operations may be between 30-50%. Much of the remaining oil is trapped in porous media. Tertiary, or enhanced oil recovery (EOR) methods, increase the mobility of oil in order to increase extraction.

There are currently several different methods for EOR, including steam flood and water flood injection and hydraulic fracturing. One method is through a water altemating-gas (WAG) process. WAG injection consists of injection of intermittent slugs of water and gas to improve gas sweep efficiency in the reservoir.

Conventional WAG methods to improve oil recovery are often marred with gas mobility issues due to density and gravity difference between gas and water. Gas has the tendency to move to upper section in a reservoir while water tends to move to the bottom of reservoir, leaving behind regions of unswept oil.

To address this issue, foam can be used to control gas mobility, gas front and early gas breakthrough - ultimately to improve gas sweep efficiency. The use of foams to enhance the WAG process is termed as “Foam -Assisted WAG” or FAWAG, referring to the addition of foaming chemicals into the injection water in the WAG cycle. Foams have an apparent viscosity greater than the displacing medium (e.g. water alone), thus lowering gas mobility in high permeability parts of the formation to recover additional oil. While foam has been used in EOR processes before, the use of conventional foaming and foam stabilizing mixtures has been problematic. For example, foam compositions in general tend to destabilize when contacted by oil. Accordingly, when used in oil recovery applications, these foam compositions may prematurely destabilize resulting in an undesired loss of sweep efficiency.

Another problem with conventional foaming and foam stabilizing mixtures is their tendency to destabilize under more severe reservoir conditions such as high temperatures (> 95 °C). The use of seawater in FAWAG also creates conditions of high salinity (> 35, 000 ppm) which reduces the life span of foams.

This is disadvantageous in oil recovery applications because foams that dissipate quickly diminish the effectiveness of FAWAG techniques and therefore limiting the oil recovery.

In addition, most developed formulations for FAWAG have not been assessed for their environmental-friendliness for offshore applications as such formulations have mainly concentrated on foam performance.

This poses a problem as there are some countries which do not have any regulations governing the use and discharge of oil recovery chemicals in offshore environments. Overboard discharge of potentially toxic and non-readily biodegradable formulations can be costly to the environment and marine creatures. Further, fluid management of such formulations for disposal into the sea after use is challenging.

Additionally, conventional foam formulations for FAWAG may be costly due to the components and their respective concentrations which make up the formulation.

Hence, there is a need to provide foam compositions useful in FAWAG processes that overcome, or at least ameliorate, one or more of the disadvantages described above.

Summary

In one aspect of the present disclosure, there is provided a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (I):

Formula (I) wherein: represents a point of attachment to the silicon dioxide;

R ¹ and R ² are each independently C1-6 alkyl, C1-6 alkoxy, or wherein - represents a point of attachment to the silicon dioxide;

L ¹ is -O-L ² - or C1-8 alkylene, and L ² is C1-8 alkylene;

R ³ , R ⁴ , R ^5a , R ^5b , R ^6a , R ^6b , R ^6c , and R ⁷ are each independently H or C1-6 alkyl; and n represents an integer greater than 1.

Advantageously, the modified silicon dioxide material may be used as a foam stabilizer in a foaming composition. The foaming composition may be a foaming composition used in enhanced oil recovery operations. The modified silicon dioxide material may be useful in creating long propagation foam in high temperature oil reservoirs by using the modified silicon dioxide material as a physical barrier to strengthen foam lamella structure. The modified silicon dioxide material may be compatible with seawater which advantageously allows the use of seawater as a carrier fluid, which is a cost effective and abundant carrier fluid.

The modified silicon dioxide material also advantageously works in high temperature environments, for example, at temperatures above 80 °C, and at high salinity of more than about 35,000 ppm.

The modified silicon dioxide material may also advantageously be used in compositions for improved oil recovery via pore channel plugging/ log jamming and wettability alteration mechanisms. The modified silicon dioxide material may also advantageously be used in compositions for improved oil recovery by stabilizing and enhance the performance of surfactants present in the composition. The compositions may be effective in reducing interfacial tension.

In another aspect of the present disclosure, there is provided a method of forming a modified silicon dioxide material disclosed herein, wherein the method comprises adding (i) monomers comprising an amide group, to (ii) at least one silicon dioxide attached with at least one group represented by Formula (A), in the presence of a (iii) polymerization initiator,

Formula (A) wherein: represents a point of attachment to the silicon dioxide;

R ¹ and R ² are each independently optionally substituted Ci-6 alkyl, optionally substituted Ci-6 alkoxy, or wherein represents a point of attachment to the silicon dioxide; and

L ¹ is -O-L ² - or optionally substituted C1-8 alkylene, and L ² is optionally substituted C1-8 alkylene.

In a further aspect of the present disclosure, there is provided a method for recovering oil from a subterranean oil-containing formation comprising:

(a) introducing a composition comprising the modified silicon dioxide material disclosed herein into the subterranean oil-containing formation;

(b) introducing a gas into the subterranean oil-containing formation, wherein the presence of the composition lowers the gas mobility within said formation; and

(c) recovering oil from the formation. Definitions

Unless otherwise defined herein, scientific and technical terms used in this application shall have the meanings that are commonly understood by those of ordinary skill in the art. Generally, nomenclature used in connection with, and techniques of, chemistry described herein, are those well-known and commonly used in the art.

Unless the context requires otherwise or specifically stated to the contrary, integers, steps, or elements of the invention recited herein as singular integers, steps or elements clearly encompass both singular and plural forms of the recited integers, steps or elements.

As used herein, unless otherwise specified, the following terms have the following meanings, and unless otherwise specified, the definitions of each term (i.e. moiety or substituent) apply when that term is used individually or as a component of another term (e .g . , the definition of aryl is the same for aryl and for the aryl portion of arylalkyl, alkylaryl, arylalkynyl, and the like).

As used herein, the term "alkyl" includes within its meaning monovalent (“alkyl”) and divalent (“alkylene”) straight chain or branched chain saturated aliphatic groups having from 1 to 20 carbon atoms, eg, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,

17, 18, 19, or 20 carbon atoms. For example, the term alkyl includes, but is not limited to, methyl, ethyl, 1 -propyl, isopropyl, 1 -butyl, 2-butyl, isobutyl, tert-butyl, amyl, 1,2- dimethylpropyl, 1,1 -dimethylpropyl, pentyl, isopentyl, hexyl, 4-methylpentyl, 1- methylpentyl, 2-methylpentyl, 3 -methylpentyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 1,2-dimethylbutyl, 1,3 -dimethylbutyl, 1,2,2-trimethylpropyl, 1,1,2-trimethylpropyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicodecyl and the like. Alkyl groups may be optionally substituted.

As used herein, the term "alkenyl" refers to divalent straight chain or branched chain unsaturated aliphatic groups containing at least one carbon-carbon double bond and having from 2 to 20 carbon atoms, eg, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,

18, 19, or 20 carbon atoms. For example, the term alkenyl includes, but is not limited to, ethenyl, propenyl, butenyl, 1-butenyl, 2-butenyl, 2-methylpropenyl, 1 -pentenyl, 2- pentenyl, 2-methylbut-l-enyl, 3-methylbut-l-enyl, 2-methylbut-2-enyl, 1 -hexenyl, 2- hexenyl, 3-hexenyl, 2,2-dimethyl-2-butenyl, 2-methyl-2-hexenyl, 3 -methyl- 1 -pentenyl, 1,5-hexadienyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, nonadecenyl, eicodecenyl and the like. Alkenyl groups may be optionally substituted. As used herein, the term “olefin” refers to alkenyl with one carbon-carbon double bond. An “alpha-olefin” refers to an olefin having a double bond at the primary or alpha position. As used herein, the term "alkynyl" refers to divalent straight chain or branched chain unsaturated aliphatic groups containing at least one carbon-carbon triple bond and having from 2 to 20 carbon atoms, eg, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms. For example, the term alkynyl includes, but is not limited to, ethynyl, propynyl, butynyl, 1-butynyl, 2-butynyl, 2-methylpropynyl, 1 -pentynyl, 2- pentynyl, 2-methylbut-l-ynyl, 3-methylbut-l-ynyl, 2-methylbut-2-ynyl, 1 -hexynyl, 2- hexynyl, 3-hexynyl, 2,2-dimethyl-2-butynyl, 2-methyl-2-hexynyl, 3-methyl-l -pentynyl, 1,5-hexadiynyl, heptynyl, octynyl, nonynyl, decynyl, undecynyl, dodecynyl, tridecynyl, tetradecynyl, pentadecynyl, hexadecynyl, heptadecynyl, octadecynyl, nonadecynyl, eicodecynyl and the like. Alkynyl groups may be optionally substituted.

The term “carbocycle”, or variants such as “carbocyclic ring” as used herein, includes within its meaning any stable 3, 4, 5, 6, or 7-membered monocyclic or bicyclic or 7, 8, 9, 10, 1 1, 12, or 13-membered bicyclic or tricyclic, any of which may be saturated, partially unsaturated, or aromatic. The term “carbocycle” includes within its meaning cycloalkyl, cycloalkenyl and aryl groups. Examples of such carbocycles include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, cyclooctyl, [3.3.0]bicyclooctane, [4 ,3.0]bicyclononane, [4.4.0]bicyclodecane (decalin), [2.2.2]bicyclooctane, fluorenyl, phenyl, naphthyl, indanyl, adamantyl, or tetrahydronaphthyl (tetralin). Preferred carbocycles, unless otherwise specified, are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, and indanyl. Carbocycles may be optionally substituted.

The term "cycloalkyl" as used herein refers to a non-aromatic mono- or multicyclic ring system comprising about 3 to about 10 carbon atoms. The cycloalkyl can be optionally substituted with one or more "ring system substituents" which may be the same or different, and are as defined herein. Non-limiting examples of suitable monocyclic cycloalkyls include cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl and the like. Nonlimiting examples of suitable multicyclic cycloalkyls include 1 -decalinyl, norbomyl, adamantyl and the like. Further non-limiting examples of cycloalkyl include the following:

The term "cycloalkenyl" as used herein refers to a non-aromatic mono or multicyclic ring system comprising about 3 to about 10 carbon atoms which contains at least one carbon-carbon double bond. Non-limiting examples of suitable monocyclic cycloalkenyls include cyclopentenyl, cyclohexenyl, cyclohepta- 1,3-dienyl, and the like. Non-limiting example of a suitable multicyclic cycloalkenyl is norbomylenyl, as well as unsaturated moieties of the examples shown above for cycloalkyl. Cycloalkenyl groups may be optionally substituted.

The term “aryl”, or variants such as “aromatic group” or “arylene” as used herein refers to monovalent (“aryl”) and divalent (“arylene”) single, polynuclear, conjugated or fused residues of aromatic hydrocarbons having from 6 to 10 carbon atoms. Such groups include, for example, phenyl, biphenyl, naphthyl, phenanthrenyl, and the like. Aryl groups may be optionally substituted.

The term “halogen”, or variants such as “halide” or “halo” as used herein, includes within its meaning fluorine, chlorine, bromine and iodine.

The term "heteroaryl" as used herein refers to an aromatic monocyclic or multicyclic ring system comprising about 5 to about 14 ring atoms, preferably about 5 to about 10 ring atoms, in which one or more of the ring atoms is an element other than carbon, for example nitrogen, oxygen or sulfur, alone or in combination. "Heteroaryl" may also include a heteroaryl as defined above fused to an aryl as defined above. Non- limiting examples of suitable heteroaryls include pyridyl, pyrazinyl, furanyl., thienyl, pyrimidinyl, pyridone (including N-substituted pyridones), isoxazolyl, isothiazolyl, oxazolyl, thiazolyl, pyrazolyl, furazanyl, pyrrolyl, pyrazolyl, triazolyl, 1 ,2,4-thiadiazolyl, pyrazinyl, pyridazmyl, quinoxalinyl, phthalazinyl, oxindolyl, imidazo[l ,2-a]pyridmyl, imidazo[2,l -b]thiazolyl, benzofurazanyl, indolyl, azaindolyl, benzimidazolyl, benzothienyl, quinolinyl, imidazolyl, thienopyridyl, quinazolinyl, thienopyrimidyl, pyrrolopyridyl, imidazopyridyl, isoquinolinyl, benzoazaindolyl, 1 ,2,4-triazinyI, benzothiazolyl and the like. The term "heteroaryl" also refers to partially saturated heteroaryl moieties such as, for example, tetrahydroisoquinolyl, tetrahydroquinolyl and the like. Heteroaryl groups may be optionally substituted.

The term "heterocycle" as used herein refers to a group comprising a covalently closed ring herein at least one atom forming the ring is a carbon atom and at least one atom forming the ring is a heteroatom. Heterocyclic rings may be formed by three, four, five, six, seven, eight, nine, or more than nine atoms, any of which may be saturated, partially unsaturated, or aromatic. Any number of those atoms may be heteroatoms (i.e., a heterocyclic ring may comprise one, two, three, four, five, six, seven, eight, nine, or more than nine heteroatoms). Herein, whenever the number of carbon atoms in a heterocycle is indicated (e.g., C1-C6 heterocycle), at least one other atom (the heteroatom) must be present in the ring. Designations such as "C1-C6 heterocycle" refer only to the number of carbon atoms in the ring and do not refer to the total number of atoms in the ring. It is understood that the heterocylic ring will have additional heteroatoms in the ring. In heterocycles comprising two or more heteroatoms, those two or more heteroatoms may be the same or different from one another. Heterocycles may be optionally substituted. Binding to a heterocycle can be at a heteroatom or via a carbon atom. Examples of heterocycles include heterocycloalkyls (where the ring contains fully saturated bonds) and heterocycloalkenyls (where the ring contains one or more unsaturated bonds) such as, but are not limited to the following:

wherein D, E, F, and G independently represent a heteroatom. Each of D, E, F, and G may be the same or different from one another.

The term “optionally substituted” as used herein means the group to which this term refers may be unsubstituted, or may be substituted with one, two, three or more groups other than hydrogen provided that the indicated atom’s normal valency is not exceeded, and that the substitution results in a stable compound. Such groups may be, for example, halogen, hydroxy, oxo, cyano, nitro, alkyl, alkoxy, haloalkyl, haloalkoxy, aryl alkoxy, alkylthio, hydroxyalkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkoxy, alkanoyl, alkoxycarbonyl, alkylsulfonyl, alkylsulfonyloxy, alkylsulfonylalkyl, arylsulfonyl, arylsulfonyloxy, arylsulfonylalkyl, alkylsulfonamido, alkylamido, alkylsulfonamidoalkyl, alkylamidoalkyl, arylsulfonamido, arylcarboxamido, aiylsulfonamidoalkyl, arylcarboxamidoalkyl, aroyl, aroyl4alkyl, arylalkanoyl, acyl, aryl, arylalkyl, alkylaminoalkyl, a group R ^x R ^y N-, R ^x 0C0(CHi)m, R ^x CON(R ^y )(CH2)m, R ^X R ^V NCO( CH 2 )m, R ^x R ^y NSO2(CH ₂ )m or R ^x SO ₂ NR ^y (CH2)m (where each of R ^x and R ^y is independently selected from hydrogen or alkyl , or where appropriate R ^x R ^y forms part of carbocy lie or heterocyclic ring and m is 0, 1 , 2, 3 or 4), a group R ^x R ^y N(CH2)p- or R ^x R ^y N(CHz)pO- (wherein p is 1 , 2, 3 or 4); wherein when the substituent is R ^x R ^y N(CH2.)p- or R ^x R ^y N(CH2)pO, R ^x with at least one CH2 of the (CH2)p portion of the group may also form a carbocyclyl or heterocyclyl group and R ^y may be hydrogen, alkyl.

The word “substantially” does not exclude “completely” e.g. a composition which is “substantially free” from Y may be completely free from Y. Where necessary, the word “substantially” may be omitted from the definition of the invention.

Unless specified otherwise, the terms "comprising" and "comprise", and grammatical variants thereof, are intended to represent "open" or "inclusive" language such that they include recited elements but also permit inclusion of additional, unrecited elements. As used herein, the term "about", in the context of concentrations of components of the formulations, typically means +/- 5% of the stated value, more typically +/- 4% of the stated value, more typically +/- 3% of the stated value, more typically, +/- 2% of the stated value, even more typically +/- 1% of the stated value, and even more typically +/- 0.5% of the stated value.

Throughout this disclosure, certain embodiments may be disclosed in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the disclosed ranges. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

Certain embodiments may also be described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the disclosure. This includes the generic description of the embodiments with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.

Brief Description of Drawings

The accompanying drawings illustrate a disclosed embodiment and serves to explain the principles of the disclosed embodiment. It is to be understood, however, that the drawings are designed for purposes of illustration only, and not as a definition of the limits of the invention.

[Fig.l]

Fig. 1 shows the reaction mechanism of the synthesis of a modified silicon dioxide material of the present invention (PAM grafted SiO2-KH570 particles).

[Fig. 2]

Fig. 2 shows the Nuclear Magnetic Resonance (NMR) pattern of PAM grafted SiCh- KH570 particles. [Fig. 3A]

Fig. 3A shows the Fourier Transform Infrared Spectroscopy (FTIR) spectra of SiO2- KH570 particles (peaks at a: 3378.86 cm ^-1 , b: 1630.64 cm ^-1 ; c: 1079.34 cm ^-1 ; d: 962.10 cm ^-1 ; e: 800.77 cm ^-1 ).

[Fig. 3B]

Fig. 3B shows the FTIR spectra of PAM (peaks at a: 3311.85 cm ^-1 ; b: 3190.23 cm ^-1 ; c: 2935.56 cm ^-1 ; d: 2327.31 cm ^-1 ; e: 2074.74 cm ^-1 ; f: 1736.17 cm ^-1 ; g: 1645.13 cm ^-1 ; h: 1602.33 cm ^-1 ; i: 1446.61 cm ^-1 ; j: 1410.70 cm ^-1 ; k: 1350.09 cm ^-1 ; 1: 1014.33 cm ^-1 ; m: 763.25 cm ^-1 ).

[Fig. 3C]

Fig. 3C shows the FTIR spectra of PAM grafted SiO2-KH570 particles (peaks at a: 3340 cm ^-1 ; b:(3180-2940 cm ^-1 ); c: 1740 cm ^-1 ; d: (1650-1600 cm ^-1 ); e: (1445 - 1370 cm ^-1 ; f : 1220 cm ^-1 ; g: 1090 cm ^-1 ; h: 910 cm ^-1 ; i: 780 cm ^-1 ).

[Fig. 4]

Fig. 4 shows the Thermalgravimetric analysis (TGA) pattern of PAM grafted SiO2- KH570 particles.

[Fig. 5]

Fig. 5 shows the Field Emission Scanning Electron Microscopy (FESEM) of PAM grafted SiO2-KH570 particles.

[Fig. 6]

Fig. 6 shows the Transmission Electron Microscopy (TEM) of PAM grafted SiCh- KH570 particles.

[Fig. 7]

Fig. 7 shows the Energy Dispersive X-Ray Analysis (EDX) spectra of PAM grafted SiO2-KH570 particles.

Detailed Disclosure of Embodiments

The present invention relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (I):

represents a point of attachment to the silicon dioxide;

R ¹ and R ² are each independently optionally substituted Ci-6 alkyl, optionally substituted Ci-6 alkoxy, or -O - , wherein - represents a point of attachment to the silicon dioxide;

L ¹ is -O-L ² - or optionally substituted C1-8 alkylene, and L ² is optionally substituted C1-8 alkylene;

R ³ , R ⁴ , R ^5a , R ^5b , R ^6a , R ^6b , R ^6C , and R ⁷ are each independently H or optionally substituted Ci-6 alkyl; and n represents an integer greater than 1.

The modified silicon dioxide material may be useful in compositions for enhanced oil recovery operations. Such compositions may have high enhanced oil recovery performance and may be environmentally-friendly, to reduce the burden of fluid management.

When present in foaming compositions, the modified silicon dioxide material may be useful in stabilizing foams in subterranean environments of high temperatures (for example, above 80 °C), and tolerant to crude oil (which is known to be deleterious to foams).

The modified silicon dioxide material may also provide compositions it is present in with high temperature tolerance (for example, above 80 °C) and may reduce adsorption to reservoir walls. The modified silicon dioxide material may also provide negative charges to the composition, thus providing electrical repulsion between two opposite faces of foam lamella to prevent foam thinning and making it less sensitive to adsorption on clayey reservoirs.

R ¹ may be selected from optionally substituted alkyl, or optionally substituted alkoxy. R ¹ may be optionally substituted Ci-6 alkyl or optionally substituted Ci-6 alkoxy. R ¹ may be optionally substituted Ci, C2, C3, C4, C5, or C6 alkyl or optionally substituted Ci, C2, C3, C4, C5, or C6 alkoxy. R ¹ may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ¹ may be methoxy, ethoxy, propoxy, butoxy, pentoxy, or hexoxy. R ¹ may be substituted or unsubstituted. The optional substituents on R ¹ may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C 1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

In another embodiment, R ¹ may represent -O - , wherein - represents a point of attachment to the silicon dioxide.

R ² may be selected from optionally substituted alkyl, or optionally substituted alkoxy. R ² may be optionally substituted C1-6 alkyl or optionally substituted C1-6 alkoxy. R ² may be optionally substituted Ci, C2, C3, C4, C5, or C6 alkyl or optionally substituted Ci, C2, C3, C4, C5, or Ce alkoxy. R ² may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ² may be methoxy, ethoxy, propoxy, butoxy, pentoxy, or hexoxy. R ² may be substituted or unsubstituted. The optional substituents on R ² may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C 1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

In another embodiment, R ² may represent -O - , wherein - represents a point of attachment to the silicon dioxide.

L ¹ may be -O-L ² -, wherein L ² is optionally substituted alkylene. The -O- in L ¹ may be attached to the -C(O)- group in Formula (I), or may be attached the -Si- group. R ² may be optionally substituted C1-8 alkylene. R ² may be optionally substituted methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene. R ² may be substituted or unsubstituted. The optional substituents on R ² may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen. L ¹ may be -O- (CH2)3-, wherein the -O- is attached to the -C(O)- group in L ¹ .

In another embodiment, L ¹ may be optionally substituted alkylene. L ¹ may be optionally substituted C1-8 alkylene. L ¹ may be optionally substituted methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene. L ¹ may be substituted or unsubstituted. The optional substituents on L ¹ may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

R ³ may be selected from H or optionally substituted alkyl. R ³ may be H or optionally substituted C1-6 alkyl. R ³ may be H or optionally substituted Ci, C2, C3, C4, C5, or Ce alkyl. R ³ may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ³ may be substituted or unsubstituted. The optional substituents on R ³ may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C 1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

R ⁴ may be selected from H or optionally substituted alkyl. R ⁴ may be H or optionally substituted C1-6 alkyl. R ⁴ may be H or optionally substituted Ci, C2, C3, C4, C5, or C6 alkyl. R ⁴ may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ⁴ may be substituted or unsubstituted. The optional substituents on R ⁴ may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C 1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

R ^5a may be selected from H or optionally substituted alkyl. R ^5a may be H or optionally substituted C1-6 alkyl. R ^5a may be H or optionally substituted Ci, C2, C3, C4, C5, or C6 alkyl. R ^5a may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ^5a may be substituted or unsubstituted. The optional substituents on R ^5a may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

R ^5b may be selected from H or optionally substituted alkyl. R ^5b may be H or optionally substituted C1-6 alkyl. R ^5b may be H or optionally substituted Ci, C2, C3, C4, C5, or C6 alkyl. R ^5b may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ^5b may be substituted or unsubstituted. The optional substituents on R ^5b may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

R ^6a may be selected from H or optionally substituted alkyl. R ^6a may be H or optionally substituted C1-6 alkyl. R ^6a may be H or optionally substituted Ci, C2, C3, C4, C5, or C6 alkyl. R ^6a may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ⁴ may be substituted or unsubstituted. The optional substituents on R ^6a may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

R ^6b may be selected from H or optionally substituted alkyl. R ^6b may be H or optionally substituted C1-6 alkyl. R ^6b may be H or optionally substituted Ci, C2, C3, C4, C5, or C6 alkyl. R ^6b may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ^6b may be substituted or unsubstituted. The optional substituents on R ^6b may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

R ^6c may be selected from H or optionally substituted alkyl. R ^6c may be H or optionally substituted C1-6 alkyl. R ^6c may be H or optionally substituted Ci, C2, C3, C4, C5, or C6 alkyl. R ^6c may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ^6c may be substituted or unsubstituted. The optional substituents on R ^6c may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

R ⁷ may be selected from H or optionally substituted alkyl. R ⁷ may be H or optionally substituted C1-6 alkyl. R ⁷ may be H or optionally substituted Ci, C2, C3, C4, C5, or C6 alkyl. R ⁷ may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ⁷ may be substituted or unsubstituted. The optional substituents on R ⁷ may be C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C 1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen. n represents an integer greater than 1. In an embodiment, n is in the range of 1 to 1000, 25 to 1000, 50 to 1000, 75 to 1000, 100 to 1000, 125 to 1000, 150 to 1000, 175 to 1000, 200 to 1000, 225 to 1000, 250 to 1000, 275 to 1000, 300 to 1000, 325 to 1000, 350 to 1000, 375 to 1000, 400 to 1000, 400 to 1000, 425 to 1000, 450 to 1000, 475 to 1000, 500 to 1000, 525 to 1000, 550 to 1000, 575 to 1000, 600 to 1000, 625 to 1000, 650 to 1000, 675 to 1000, 700 to 1000, 725 to 1000, 750 to 1000, 775 to 1000, 800 to 1000, 825 to 1000, 850 to 1000, 875 to 1000, 900 to 1000, 925 to 1000, 950 to 1000, 975 to 1000, 1 to 975, 1 to 950, 1 to 925, 1 to 900, 1 to 875, 1 to 850, 1 to 825, 1 to 800, 1 to 775, 1 to 750, 1 to 725, 1 to 700, 1 to 675, 1 to 650, 1 to 625, 1 to 600, 1 to 575, 1 to 550, 1 to 525, 1 to 500, 1 to 475, 1 to 450, 1 to 425, 1 to 400, 1 to 375, 1 to 350, 1 to 325, 1 to 300, 1 to 275, 1 to 250, 1 to 225, 1 to 200, 1 to 175, 1 to 150, 1 to 125, 1 to 100, 1 to 75, 1 to 50, 1 to 25, or 1, 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950, 975, 1000, or any value or range therebetween.

In Formula (I), one of R ¹ or R ² may be -O - . In Formula (I), both of R ¹ or R ² may be -O - .

The present invention also relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (IB):

Formula (IB) wherein - , R ¹ , R ² , R ³ , R ⁴ , R ^5a , R ^5b , R ^6c , R ⁷ , n, and L ¹ are as defined above.

The present invention also relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (IC):

Formula (IC) wherein - , R ¹ , R ² , R ³ , R ⁴ , R ⁷ , n, and L ¹ are as defined above. The present invention also relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (ID):

Formula (ID) wherein - , R ¹ , R ² , R ⁷ , n, and L ¹ are as defined above.

The present invention also relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (IE):

Formula (IE) wherein - , R ¹ , R ² , R ³ , R ⁴ , R ^5a , R ^5b , R ^6a , R ^6b , R ^6c , R ⁷ , and n are as defined above.

The present invention also relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (IF):

Formula (IF) wherein - , R ¹ , R ² , R ³ , R ⁴ , R ^5a , R ^5b , R ^6c , R ⁷ , and n are as defined above.

The present invention also relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (IG): wherein - , R ¹ , R ² , R ³ , R ⁴ , R ⁷ , and n are as defined above. The present invention also relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (IH): wherein - , R ¹ , R ² , R ⁷ , and n are as defined above. The present invention also relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (IJ): wherein - , R ¹ , R ² , R ³ , R ⁴ , R ^5a , R ^5b , R ^6a , R ^6b , R ^6c , R ⁷ , n, and L ¹ are as defined above.

The present invention also relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (IK):

Formula (IK) wherein - , R ¹ , R ² , R ³ , R ⁴ , R ^5a , R ^5b , R ^6a , R ^6b , R ^6c , R ⁷ , n, and L ¹ are as defined above. The present invention also relates to a modified silicon dioxide material, wherein a silicon dioxide of the modified silicon dioxide material is attached with at least one group represented by Formula (IA): wherein:

- represents a point of attachment to the silicon dioxide; and n represents an integer greater than 1.

The modified silicon material may have at least one group represented by Formula (I), (IA), (IB), (IC), (ID), (IE), (IF), (IG), (IH), (IJ), or (IK) attached to the silicon dioxide. The modified silicon material may have at least two groups, at least three groups, at least four groups, at least five groups, at least six groups, at least seven groups, at least eight groups, at least 9 groups, or at least 10 groups represented by Formula (I), (IA), (IB), (IC), (ID), (IE), (IF), (IG), (IH), (IJ), and/or (IK) attached to the silicon dioxide.

The modified silicon material may be represented by one of the following Structures 1, 2, 3, 4, 5, 6 or 7:

[Structure 1]

[Structure 2]

[Structure 3]

[Structure 5]

wherein nl, n2, n3 are at least 1, and are each independently the same or different.

[Structure 7] wherein nl, n2, n3 are at least 1, and are each independently the same or different. nl, n2 and n3 may independently be in the range of 1 to 1000, 25 to 1000, 50 to

1000, 75 to 1000, 100 to 1000, 125 to 1000, 150 to 1000, 175 to 1000, 200 to 1000, 225 to 1000, 250 to 1000, 275 to 1000, 300 to 1000, 325 to 1000, 350 to 1000, 375 to 1000, 400 to 1000, 400 to 1000, 425 to 1000, 450 to 1000, 475 to 1000, 500 to 1000, 525 to 1000, 550 to 1000, 575 to 1000, 600 to 1000, 625 to 1000, 650 to 1000, 675 to 1000, 700 to 1000, 725 to 1000, 750 to 1000, 775 to 1000, 800 to 1000, 825 to 1000, 850 to 1000, 875 to 1000, 900 to 1000, 925 to 1000, 950 to 1000, 975 to 1000, 1 to 975, 1 to 950, 1 to 925, 1 to 900, 1 to 875, 1 to 850, 1 to 825, 1 to 800, 1 to 775, 1 to 750, 1 to 725, 1 to 700, 1 to 675, 1 to 650, 1 to 625, 1 to 600, 1 to 575, 1 to 550, 1 to 525, 1 to 500, 1 to 475, 1 to 450, 1 to 425, 1 to 400, 1 to 375, 1 to 350, 1 to 325, 1 to 300, 1 to 275, 1 to 250, 1 to 225, 1 to 200, 1 to 175, 1 to 150, 1 to 125, 1 to 100, 1 to 75, 1 to 50, 1 to 25, or 1, 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950, 975, 1000, or any value or range therebetween.

The modified silicon dioxide material may have a particle size of about 20 nm to about 200 nm, about 30 nm to about 200 nm, about 40 nm to about 200 nm, about 50 nm to about 200 nm, about 60 nm to about 200 nm, about 70 nm to about 200 nm, about 80 nm to about 200 nm, about 90 nm to about 200 nm, about 100 nm to about 200 nm, about 110 nm to about 200 nm, about 120 nm to about 200 nm, about 130 nm to about 200 nm, about 140 nm to about 200 nm, about 150 nm to about 200 nm, about 160 nm to about 200 nm, about 170 nm to about 200 nm, about 180 nm to about 200 nm, about 190 nm to about 200 nm, about 20 nm to about 190 nm, about 20 nm to about 180 nm, about 20 nm to about 170 nm, about 20 nm to about 160 nm, about 20 nm to about 150 nm, about 20 nm to about 140 nm, about 20 nm to about 130 nm, about 20 nm to about 120 nm, about 20 nm to about 110 nm, about 20 nm to about 100 nm, about 20 nm to about 90 nm, about 20 nm to about 80 nm, about 20 nm to about 70 nm, about 20 nm to about 60 nm, about 20 nm to about 50 nm, about 20 nm to about 40 nm, about 20 nm to about 30 nm, or about 20 nm, about 30 nm, about 40 nm, about 50 nm, about 60 nm, about 70 nm, about 80 nm, about 90 nm, about 100 nm, about 110 nm, about 120 nm, about 130 nm, about 140 nm, about 150 nm, about 160 nm, about 170 nm, about 180 nm, about 190 nm, about 200 nm, or any value or range therebetween.

The modified silicon dioxide may have an average molecular weight in the range of about 120,000 g/mol to about 150,000 g/mol, about 125,000 g/mol to about 150,000 g/mol, about 130,000 g/mol to about 150,000 g/mol, about 135,000 g/mol to about 150,000 g/mol, about 140,000 g/mol to about 150,000 g/mol, about 145,000 g/mol to about 150,000 g/mol, about 120,000 g/mol to about 145,000 g/mol, about 120,000 g/mol to about 140,000 g/mol, about 120,000 g/mol to about 135,000 g/mol, about 120,000 g/mol to about 130,000 g/mol, about 120,000 g/mol to about 125,000 g/mol, or about 120,000 g/mol, about 125,000 g/mol, about 130,000 g/mol, about 135,000 g/mol, about 140,000 g/mol, about 140,000 g/mol, about 150,000 g/mol, or any value or range therebetween.

The present invention also relates to method of forming a modified silicon dioxide material disclosed herein, wherein the method comprises adding (i) monomers comprising an amide group, to (ii) at least one silicon dioxide attached with at least one group represented by Formula (A), in the presence of a (iii) polymerization initiator,

Formula (A) wherein:

- represents a point of attachment to the silicon dioxide;

R ¹ and R ² are each independently optionally substituted Ci-6 alkyl, optionally substituted Ci-6 alkoxy, or -O - , wherein - represents a point of attachment to the silicon dioxide; and

L ¹ is -O-L ² - or optionally substituted C1-8 alkylene, and L ² is optionally substituted C1-8 alkylene.

The (i) monomers comprising an amide group may be selected from the group consisting of acrylamide and acrylic acid.

In an embodiment, the method comprises adding about 1 wt% to about 5 wt% (based on the total weight of the modified silicon dioxide material) of (i) monomers comprising an amide group to the (ii) at least one silicon dioxide attached with at least one group represented by Formula (A). In an embodiment, the method comprises adding about 1 wt% to about 5wt%, about 1.5 wt% to about 5 wt%, about 2 wt% to about 5 wt%, about 2.5 wt% to about 5 wt%, about 3 wt% to about 5 wt%, about 3.5 wt% to about 5 wt%, about 4 wt% to about 5 wt%, about 4.5 wt% to about 5 wt%, about 1 wt% to about 4.5 wt%, about 1 wt% to about 4 wt%, about 1 wt% to about 3.5 wt%, about 1 wt% to about 3 wt%, about 1 wt% to about 2.5 wt%, about 1 wt% to about 2 wt%, about 1 wt% to about 1.5 wt%, about 3 wt to about 4 wt%, or about 1 wt%, about 1.5 wt%, about 2 wt%, about 2.5 wt%, about 3 wt%, about 3.5 wt%, about 4 wt%, about 4.5 wt%, about 5 wt%, or any value or range therebetween, (based on the total weight of the modified silicon dioxide material) of (i) monomers comprising an amide group.

In an embodiment, the method may be performed at a temperature of about 30 °C to about 60 °C, about 35 °C to about 60 °C, about 40 °C to about 60 °C, about 45 °C to about 60 °C, about 50 °C to about 60 °C, about 55 °C to about 60 °C, about 30 °C to about 55 °C, about 30 °C to about 50 °C, about 30 °C to about 45 °C, about 30 °C to about 40 °C, about 30 °C to about 35 °C, about 30 °C, about 35 °C, about 40 °C, about 45 °C, about 50 °C, about 55 °C, about 60 °C, or any value or range therebetween.

In an embodiment, the (ii) at least one silicon dioxide attached with at least one group represented by Formula (A) is silicon dioxide attached with at least one group derived from 3 -methacryloxypropyltrimethoxy silane.

The (iii) polymerization initiator may be ammonium persulfate or potassium persulfate.

In an embodiment, the method further comprises drying the productto form a powder. The product may be dried at room temperature or higher. The product may be dried at a temperature of about 25 °C to about 70 °C, about 30 °C to about 70 °C, about 35 °C to about 70 °C, about 40 °C to about 70 °C, about 45 °C to about 70 °C, about 50 °C to about 70 °C, about 55 °C to about 70 °C, about 60 °C to about 70 °C, about 65 °C to about 70 °C, about 25 °C to about 65 °C, about 25 °C to about 60 °C, about 25 °C to about 55 °C, about 25 °C to about 50 °C, about 25 °C to about 45 °C, about 25 °C to about 40 °C, about 25 °C to about 35 °C, about 25 °C to about 30 °C, or about 25 °C, about 30 °C, about 35 °C, about 40 °C, about 45 °C, about 50 °C, about 55 °C, about 60 °C, about 65 °C, about 70 °C, or any value or range therebetween.

The product may be dried for a period of about 1 hour to about 6 hours, about 1.5 hours to about 6 hours, about 2 hours to about 6 hours, about 2.5 hours to about 6 hours, about 3 hours to about 6 hours, about 3.5 hours to about 6 hours, about 4 hours to about 6 hours, about 4.5 hours to about 6 hours, about 5 hours to about 6 hours, about 5.5 hours to about 6 hours, about 1 hour to about 5.5 hours, about 1 hour to about 5 hours, about 1 hour to about 4.5 hours, about 1 hour to about 4 hours, about 1 hour to about 3.5 hours, about 1 hour to about 3 hours, about 1 hour to about 2.5 hours, about 1 hour to about 2 hours, about 1 hour to about 1.5 hours, or about 1 hour, about 1.5 hours, about 2 hours, about 2.5 hours, about 3 hours, about 3.5 hours, about 4 hours, about 4.5 hours, about 5 hours, about 5.5 hours, about 6 hours, or any value or range therebetween.

In the method, 0.05 g of (iii) polymerization initiator may be added to 0.525 g of SiO2-KH570 and 5.5 g of acrylamide monomers.

The present invention also relates to a method of forming a modified silicon dioxide material of any of the preceding claims, comprising:

(a) preparing a mixture of SiO2 particles and a compound of Formula (II):

6

Formula (II) wherein:

R ¹ , R ² , and R ⁸ are independently Ci-6 alkyl or Ci-6 alkoxy,

L ¹ is O-L ² - or C1-8 alkylene, and L ² is C1-8 alkylene,

R ^9a is =CH ₂ , =CH-CH ₃ , =CH-CH ₂ -CH ₃ , =CH-(CH ₂ ) ₂ -CH ₃ , =CH-(CH ₂ ) ₃ - CH ₃ , =CH-(CH ₂ )4-CH ₃ , and

R ^9b is H or Ci-6 alkyl;

(b) adding monomers comprising an amide group to the mixture of step (a) in the presence of a polymerization initiator.

R ⁸ may be selected from optionally substituted alkyl, or optionally substituted alkoxy. R ⁸ may be optionally substituted C1-6 alkyl or optionally substituted C1-6 alkoxy. R ⁸ may be optionally substituted C ₁ , C ₂ , C ₃ , C ₄ , C ₅ , or C ₆ alkyl or optionally substituted C ₁ , C ₂ , C ₃ , C ₄ , C ₅ , or C ₆ alkoxy. R ⁸ may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ⁸ may be methoxy, ethoxy, propoxy, butoxy, pentoxy, or hexoxy. R ⁸ may be substituted or unsubstituted. The optional substituents on R ⁸ may be C1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl, C 1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

R ^9a may be =CH ₂ , =CH-CH ₃ , =CH-CH ₂ -CH ₃ , =CH-(CH ₂ ) ₂ -CH ₃ , =CH- (CH ₂ ) ₃ -CH ₃ , =CH-(CH ₂ )4-CH ₃ .

R ^9b may be selected from H or optionally substituted alkyl. R ^9b may be H or optionally substituted C1-6 alkyl. R ^9b may be H or optionally substituted C ₁ , C ₂ , C ₃ , C ₄ , C ₅ , or C ₆ alkyl. R ^9b may be methyl, ethyl, propyl, butyl, pentyl, hexyl. R ^9b may be substituted or unsubstituted. The optional substituents on R ^9b may be C1-6 alkyl, C ₂ -6 alkenyl, C ₂ -6 alkynyl, C1-6 alkoxy, amino, sulfinyl, sulfonyl, carbonyl, aryl, heteroaryl, carbocyclyl, or heterocyclyl, hydroxyl, carboxylic acid, cyano or halogen.

The mixture of step (a) may comprise about 0. 1 g to about 1 g of SiO ₂ , or about 0.2 g to about 1 g of SiO ₂ , about 0.3 g to about 1 g of SiO ₂ , about 0.4 g to about 1 g of SiO ₂ , about 0.5 g to about 1 g of SiO ₂ , about 0.6 g to about 1 g of SiO ₂ , about 0.7 g to about 1 g of SiO ₂ , about 0.8 g to about 1 g of SiCh, about 0.9 g to about 1 g of SiO ₂ , about 0. 1 g to about 0.9 g of SiO ₂ , about 0. 1 g to about 0.8 g of SiO ₂ , about 0.1 g to about 0.9 g of SiO2, about 0.1 g to about 0.6 g of SiO2, about 0.1 g to about 0.5 g of SiO2, about 0.1 g to about 0.4 g of SiO2, about 0.1 g to about 0.3 g of SiO2, about 0.1 g to about 0.2 g of SiO2, about 0.1 g, about 0.2 g, about 0.3 g, about 0.4 g, about 0.5 g, about 0.6 g, about 0.7 g, about 0.8 g, about 0.9 g, about 1.0 g, or any value or range therebetween of SiO2.

The mixture of step (a) may comprise about 1 wt% to about 5 wt% of compound of Formula (II), or about 1.5 wt% to about 5 wt%, about 2 wt% to about 5 wt%, about

2.5 wt%to about 5 wt%, about 3 wt%to about 5 wt%, about 3.5 wt%to about 5 wt%, about 4 wt% to about 5 wt%, about 4.5 wt% to about 5 wt%, about 1 wt% to about

4.5 wt%, about 1 wt% to about 4 wt%, about 1 wt% to about 3.5 wt%, about 1 wt% to about 3 wt%, about 1 wt% to about 2.5 wt%, about 1 wt% to about 2 wt%, about 1 wt% to about 1.5 wt%, or about 1 wt %, about 1.5 wt %, about 2 wt %, about 2.5 wt %, about 3 wt %, about 3.5 wt %, about 4 wt %, about 4.5 wt %, about 5 wt %, or any value or range therebetween of compound of Formula (II).

In an embodiment, the method further comprises step (c) drying the product of step (b) to form a powder. The product may be dried at room temperature or higher. The product may be dried at a temperature of about 25 °C to about 70 °C, about 30 °C to about 70 °C, about 35 °C to about 70 °C, about 40 °C to about 70 °C, about 45 °C to about 70 °C, about 50 °C to about 70 °C, about 55 °C to about 70 °C, about 60 °C to about 70 °C, about 65 °C to about 70 °C, about 25 °C to about 65 °C, about 25 °C to about 60 °C, about 25 °C to about 55 °C, about 25 °C to about 50 °C, about 25 °C to about 45 °C, about 25 °C to about 40 °C, about 25 °C to about 35 °C, about 25 °C to about 30 °C, or about 25 °C, about 30 °C, about 35 °C, about 40 °C, about 45 °C, about 50 °C, about 55 °C, about 60 °C, about 65 °C, about 70 °C, or any value or range therebetween.

In the method, 0.05 g of (iii) polymerization initiator may be added to 0.525 g of SiO2-KH570 and 5.5 g of acrylamide monomers.

The modified silicon dioxide material may be used in an oil recovery process. The modified silicon dioxide material may be used in an enhanced oil recovery process.

The modified silicon dioxide material may be used as a foam stabilizer in a foaming composition. The foaming composition may be a foaming composition used in enhanced oil recovery operations. The modified silicon dioxide material may be useful in creating long propagation foam in high temperature oil reservoirs by using the modified silicon dioxide material as a physical barrier to strengthen foam lamella structure. The modified silicon dioxide material may be compatible with seawater which advantageously allows the use of seawater as a carrier fluid, which is a cost effective and abundant carrier fluid. The composition when used as a foam, may have gas mobility reduction factor (MRF) above between about 70 to about 210, about 80 to about 210, about 90 to about 210, about 100 to about 210, about 110 to about 210, about 120 to about 210, about 130 to about 210, about 140 to about 210, about 150 to about 210, about 160 to about 210, about 170 to about 210, about 180 to about 210, about 190 to about 210, about 200 to about 210, about 70 to about 210, about 70 to about 200, about 70 to about 190, about 70 to about 180, about 70 to about 170, about 70 to about 160, about 70 to about 150, about 70 to about 140, about 70 to about 130, about 70 to about 120, about 70 to about 110, about 70 to about 100, about 70 to about 90, about 70 to about 80, or about 70, about 80, about 90, about 100, about 110, about 120, or any value or range therebetween.

The modified silicon dioxide material also advantageously works in high temperature environments, for example, at temperatures above 80 °C, or at a temperature range of about 80 °C to about 100 °C, about 85 °C to about 100 °C, about 90 °C to about 100 °C, about 95 °C to about 100 °C, about 80 °C to about 95 °C, about 80 °C to about 90 °C, about 80 °C to about 85 °C, about 80 °C, about 85 °C, about 90 °C, about 95 °C, about 100 °C, or any value or range therebetween.

The composition may be useful to generate stable foams at salinity of more than about 35,000 ppm, for example at a range of about 35,000 ppm to about 50,000 ppm, about 40,000 ppm to about 50,000 ppm, about 45,000 ppm to about 50,000 ppm, about 35,000 ppm to about 45,000 ppm, about 35,000 ppm to about 40,000 ppm, or about 35,000 ppm, about 40,000 ppm, about 45,000 ppm, about 50,000 ppm, or any value or range therebetween.

The modified silicon dioxide material may also be used in compositions for improved oil recovery via pore channel plugging/ log jamming and wettability alteration mechanisms. Such compositions may later the surface of rocks from water wet to extremely water wet. Such compositions are also able to divert fluid from high permeability to low permeability by reversible plugging pore throats in the rock formation.

The modified silicon dioxide material may also be used in compositions for improved oil recovery by stabilizing and enhance the performance of surfactants present in the composition. The compositions may be effective in reducing interfacial tension.

Hence, the present invention also relates to a method for recovering oil from a subterranean oil-containing formation comprising:

(a) introducing a composition comprising the modified silicon dioxide material described above into the subterranean oil-containing formation; (b) introducing a gas into the subterranean oil-containing formation, wherein the presence of the composition lowers the gas mobility within said formation; and

(c) recovering oil from the formation.

The modified silicon dioxide material disclosed herein may be part of a package introduced into a subterranean oil -containing formation by itself or with another fluid.

Examples

Non-limiting examples of the invention and a comparative example will be further described in greater detail by reference to specific Examples, which should not be construed as in any way limiting the scope of the invention.

Materials

SiO2-KH570 (SiO2-3-methacryloxypropyltrimethoxysilane) obtained from US Research Nanomaterials, Inc..

Acrylamide obtained from Sigma-Aldrich.

Example 1: Preparation of Modified Silicon Dioxide Material

0.525g SiO2-KH570 nanoparticles were dispersed in deionized waterand 5.5 g of acrylamide was added. SiO2 nanoparticles coated with KH570 and acrylamide monomers were synthesized at 45 °C using 0.05 g of ammonium persulfate to initiate polymerization on the surface of the SiO2-KH570 nanoparticles.

Ethanol was used for dewatering of the nanoparticles, and the product was dried into solid in a vacuum oven for 4 hours at 50 °C. The product was then ground into a powder.

Fig. 1 shows the reaction mechanism of the above preparation.

Example 2: Characterization of Modified Silicon Dioxide Material

The synthesized nanoparticles were characterized to confirm that grafting had occurred on the surface of SiO2. As shown in Figs. 2 to 7, polyacrylamide was successfully grafted on the surface of SiCh. It was also observed that the nanoparticles were stable in the seawater, indicating the successfulness of the grafting process.

Example 2a: Nuclear Magnetic Resonance (NMR)

As shown in Fig. 2, the interaction of the KH570 coupling agent with acrylamide monomer is indicated by the presence of a peak at chemical shift 0.78 ppm.

Example 2b: Fourier Transform Infrared Spectroscopy (FTIR)

As shown in Fig. 3, the spectra FTIR shows the co-existence of polymer and SiCh nanoparticles in the product.

Example 2c: Thermalgravimetric analysis (TGA)

As shown in Fig. 4, 10% remaining undecomposed sample are SiCh nanoparticles and it matched the percentage of the content of SiCh used in Structure 6.

The Mark-Houwink equation using intrinsic viscosity was used to determine the molecular weight. 500 ppm - 4000 ppm of Structure 6 was dissolved into synthetic seawater and the kinematic viscosity test was run at 25°C using Ubbelohde tube viscometer. The data was then used in the Mark-Houwink equation to determine the molecular weight of the product (Table 1).

[Table 1] Example 2d: Field Emission Scanning Electron Microscopy (FESEM)

As shown in Fig. 5, the modified silicon dioxide nanoparticle shows the existence of SiCh nanoparticles at all places on the flakes. Some of the SiCh nanoparticles agglomerated as shown in circles in Fig. 5.

Example 2e: Transmission Electron Microscopy (TEM)

As shown in Fig. 6, TEM image shows the SiCh nanoparticles were well dispersed and well coated by polyacrylamide.

Example 2f: Energy Dispersive X-Ray Analysis (EDX) analysis

From EDX analysis (Fig. 7), all spots (spectrum) contain carbon with the spot of white dots consisted of Silicon. This shows that polyacrylamide coats the SiCh surface in water medium.

[Table 2]

Industrial Applicability

The disclosed modified silicon dioxide material may be useful in compositions for oil recovery operations.

It will be apparent that various other modifications and adaptations of the invention will be apparent to the person skilled in the art after reading the foregoing disclosure without departing from the spirit and scope of the invention and it is intended that all such modifications and adaptations come within the scope of the appended claims.