# US 2020/0399430 A1 · Hydrogel with selective absorption for separation of liquid mixtures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0399430 A1 - Document ID: US20200399430A1 - Status: Published application - Kind: A1 - Application number: 16/968,953 - Filed: 2019-02-12 - Published: 2020-12-24 - Earliest claimed: 2018-02-12 - Assignees: University of Kansas - Applicants: The University of Kansas - Inventors: ANJANA MAHARJAN; MOHAMMADAMIN EZAZI; GIBUM KWON - Web page: https://patentgrep.com/patent/US20200399430A1 ## CPC - C08J 3/075: Macromolecular gels - C08F 220/22: Esters containing halogen - C08F 220/54: Amides {, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide} - C08F 220/56: Acrylamide; Methacrylamide - C08F 222/385: {Monomers containing two or more (meth)acrylamide groups, e.g. N,N'-methylenebisacrylamide} - C08J 3/28: Treatment by wave energy or particle radiation - C08F 220/24: containing perhaloalkyl radicals - C08J 2333/08: Homopolymers or copolymers of acrylic acid esters - C08J 2333/16: Homopolymers or copolymers of esters containing halogen atoms - C08J 2433/26: Homopolymers or copolymers of acrylamide or methacrylamide - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS ## Abstract Methods for synthesizing a hydrogel are disclosed. The method includes the steps of: (a) dissolving effective amounts of a monomer, a crosslinker, and a photoinitiator in deionized water, wherein the overall concentration is about 200 mg/ml; (b) preparing a solution of a fluorinated acrylate or diacrylate in ethanol wherein the overall concentration is about 200 mg/ml; (c) separately stirring the solutions prepared in steps (a) and (b) for approximately three hours; (c) gradually introducing the solution from step (b) into the solution from step (a); (d) stirring the resulting solution from step (c) for about two hours; and (e) exposing the solution from step (d) to UV-A irradiation for about 15 minutes. ## Claims ### Claim 1 A hydrogel, comprising effective amounts of: N-ispropylacrylamide (NIPAM); N,N′ Methylenebisacrylamide (MBAA); 2-hydroxy-2-methylpropiophenone; and 1H,1H,2H,2H-perfluorodecyl acrylate; wherein the hydrogel has the following chemical structure: ### Claim 2 (depends on 1) The hydrogel of claim 1, wherein the weight ratio of the N-isopropylacrylamide, N,N′ Methylenebisacrylamide, and 2-hydroxy-2-methylpropiophenone is 97:1:2 ### Claim 3 (depends on 1) The hydrogel of claim 1, wherein the hydrogel is selectively wetted by polar liquids. ### Claim 4 (depends on 1) The hydrogel of claim 1, wherein the wettability to polar liquids of the hydrogels is reversible based on a temperature of the hydrogel. ### Claim 5 (depends on 4) The hydrogel of claim 4, wherein the wettability to nonpolar liquids of the hydrogels is unchanged based on the temperature of the hydrogel. ### Claim 6 (depends on 1) The hydrogel of claim 1, wherein the hydrogel is recyclable by submerging the hydrogel containing a polar liquid into a solution containing equal amounts of ethanol and water and an effective amount of sodium chloride, wherein after about one hour in the solution, the hydrogel is almost completely devoid of the polar liquid. ### Claim 7 (depends on 1) The hydrogel of claim 1, wherein the hydrogel is effective to selectively absorb a polar liquid from a miscible solution comprising the polar liquid and a nonpolar liquid ### Claim 8 A method for synthesizing a hydrogel, comprising the steps of: (a) dissolving N-isopropylacrylamide, N,N′ Methylenebisacrylamide (MBAA) and 2-hydroxy-2-methylpropiophenone in deionized water to form a NIPAM solution; (b) preparing a solution of 1H,1H,2H,2H-Perfluorodecyl acrylate in ethanol; (c) separately stirring the solutions prepared in steps (a) and (b) for approximately three hours; (c) gradually introducing the solution from step (b) into the solution from step (a); (d) stirring the resulting solution from step (c) for about two hours; (e) pouring the resulting solution from step (d) into a mold and irradiating with UV-A (λ=365 nm) for about 15 minutes. ### Claim 9 (depends on 8) The method of claim 8, wherein the weight ratio of the N-isopropylacrylamide, N,N′ Methylenebisacrylamide, and 2-hydroxy-2-methylpropiophenone is 97:1:2. ### Claim 10 (depends on 9) The method of claim 9, wherein the overall concentration of the solution in step (a) is 200 mg/ml. ### Claim 11 (depends on 10) The method of claim 10, wherein the overall concentration of the solution in step (b) is 200 mg/ml. ### Claim 12 (depends on 11) The method of claim 11, wherein the weight ratio of 1H,1H,2H,2H-Perfluorodecyl acrylate to the NIPAM solution in step (c) is 9:1. ### Claim 13 (depends on 8) The method of claim 8, wherein the weight percent of MBAA is between about 0.1 and 10%. ### Claim 14 (depends on 13) The method of claim 13, wherein the weight percent of MBAA is between about 0.4 and 0.6%. ### Claim 15 A method for synthesizing a hydrogel, comprising the steps of: (a) dissolving effective amounts of a monomer, a crosslinker, and a photoinitiator in deionized water, wherein the overall concentration is about 200 mg/ml; (b) preparing a solution of a fluorinated acrylate or diacrylate in ethanol wherein the overall concentration is about 200 mg/ml; (c) separately stirring the solutions prepared in steps (a) and (b) for approximately three hours; (c) gradually introducing the solution from step (b) into the solution from step (a); (d) stirring the resulting solution from step (c) for about two hours; and (e) exposing the solution from step (d) to UV-A irradiation for about 15 minutes. ### Claim 16 (depends on 15) The method of claim 15, wherein the monomer is N-isopropylacrylamide, the cross-linker is N,N′ Methylenebisacrylamide, and the photoinitiator is 2-hydroxy-2-methylpropiophenone ### Claim 17 (depends on 16) The method of claim 16, wherein the fluorinated acrylate or diacrylate is selected from the list consisting of: 1H,1H,2H,2H-Perfluoroecyl acrylate; 1H,1H,6H,6H-Perfluoro-1,6-hexandiol diacrylate; 1H,1H,-perfluoro-n-octyl methancrylate; and 1H,1H-perfluoro-n-octyl acrylate. ### Claim 18 (depends on 15) The method of claim 15, wherein step (c) occurs in the dark. ### Claim 19 (depends on 15) The method of claim 15, wherein the solution from step (d) is formed into a mold. ### Claim 20 (depends on 15) The method of claim 15, wherein the hydrogel is effective for separating miscible and immiscible solutions.