Hydrogel with selective absorption for separation of liquid mixtures

A hydrogel made by a process comprising the steps of:

• (a) forming a NIPAM solution consisting of N-isopropylacrylamide, N,N′ Methylenebisacrylamide (MBAA), and 2-hydroxy-2-methylpropiophenone dissolved in deionized water;
• (b) preparing a solution consisting of 1H, 1H,2H,2H-Perfluorodecyl acrylate in ethanol;
• (c) separately stirring the solutions prepared in steps (a) and (b) for approximately three hours;
• (d) preparing a F-PNIPAM solution consisting of the solutions of steps (a) and (b) by introducing the solution from step (b) into the solution from step (a) and stirring for about two hours;
• and
• (e) pouring the F-PNIPAM solution from step (d) into a mold and irradiating the poured F-PNIPAM solution with UV-A for about 15 minutes;
• wherein the weight percent of MBAA crosslinking the N-isopropylacrylamide and the 1H, 1H,2H,2H-Perfluorodecyl acrylate in the hydrogel is between about 0.4 and 0.6% and the hydrogel is effective to selectively absorb a polar liquid from a solution comprising the polar liquid and a nonpolar liquid.