Smart polymer composite materials for water processing

In this thesis, three types of responsive material for water processing are developed: responsive separation membrane, responsive forward osmosis draw agent, and responsive adsorbent. Introduction of thermally responsive polymer endows the responsive membrane with controllable separation ability and high separation efficiency. The swelling behavior / kinetic study efficiently reveals the swelling pressure and FO performance of thermally responsive hydrogel draw agent, advancing the development of desired draw agent. Thermally reversible ion sorption is achieved inside the metal organic framework by amphoteric functionalization, showing high adsorption capacity, accessibility of ion adsorption sites, and excellent cycling performance

Robust thermoresponsive polymer composite membrane with switchable superhydrophilicity and superhydrophobicity for efficient oil-water separation

Herein, we report for the first time on the fabrication of a robust, thermoresponsive polymer membrane produced by the combination of an elastic polyurethane (TPU) microfiber web and poly­(<i>N</i>-isopropylacrylamide) (PNIPAM). PNIPAM hydrogel is evenly coated on the surface of TPU microfibers, and thus, the wettability of TPU-PNIPAM membrane is amplified by taking advantage of the hierarchical structure and increased surface roughness. The TPU-PNIPAM membrane possesses switchable superhydrophilicity and superhydrophobicity as the temperature of membrane changes from 25 to 45 °C. The composite membrane is shown successfully able to separate a 1 wt % oil-in-water emulsion and 1 wt % water-in-oil emulsion at 25 and 45 °C, respectively, with a high separation efficiency of ≥99.26%. Furthermore, the composite membranes show excellent mechanical properties, and they are highly flexible and mechanically tough. The smart composite membranes reported here have shown great potential for further development for practical high-efficiency oil–water separations