Abstract: A microporous, cross-linked, reversibly responsive gel obtainable from a polymeric precursor is disclosed. The microporous gels exhibit a volume change response on the order of seconds, many times faster than nonporous volume change gels of similar dimension. A method of making a microporous, fast response and reversibly responsive gel having a defined pore size and defined strut thickness is also disclosed. The method comprises preparing a polymer solution having a certain initial concentration of polymer precursor, initiating phase separation of the polymer to produce a phase separated state; cross-linking the polymer in its phase separated state or cross-linking the polymer prior in its phase separated state, or both prior to and during its phase separated state, for a certain cross-linking reaction time; and allowing gelation to be completed. Particular uses of the fast response gels are also described. In one embodiment, a method for purifying and concentrating a solute from a solution is described.

Abstract: An absorbent, microporous foam comprising a crosslinked polymer having interconnected fluid cells distributed throughout its mass, wherein the fluid cells have a diameter of between about 0.1 and about 100 .mu.m, and wherein the foam can rapidly absorb at least about twice its dry weight in fluid, is disclosed. Also disclosed is a method for producing such microporous, absorbent foams. In this method: (a) a crosslinkable polymer and a first solvent are mixed to form a stable solution which can be induced to phase separate; (b) the stable solution is induced to phase separate into a polymer concentrated phase and a polymer dilute phase; (c) the polymer is induced to crosslink in the polymer concentrated phase for a predetermined period of time thereby forming a microporous material; and (d) the microporous material is dried to produce the absorbent foam.

Abstract: An absorbent, microporous foam comprising a crosslinked polymer having interconnected fluid cells distributed throughout its mass, wherein the fluid cells have a diameter of between about 0.1 and about 100 .mu.m, and wherein the foam can rapidly absorb at least about twice its dry weight in fluid, is disclosed.A method for producing a microporous, absorbent foam is also disclosed. This method comprises the steps of:(a) mixing a cross-linkable polymer and a first solvent to form a stable solution, wherein the stable solution can be induced to phase separate;(b) inducing the stable solution to phase separate into a polymer-concentrated phase and a polymer-dilute phase after a predetermined period of time;(c) inducing crosslinking of said polymer, so that the polymer will crosslink in said concentrated phase for a predetermined period of time during phase separation to thereby form a microporous material; and(d) drying the microporous material to produce the absorbent foam.