Flexible Sponge Ball-like Temperature-Responsive Molecularly Imprinted Polymer with Self-Driven “Transformation Recovery” and Mechanism Exploration

Flexible sponge ball-like temperature-responsive surface molecular imprinting polymer (ST-SMIP) with the property of self-driven "transformation recovery" for selective identification of p-nitrophenol (p-NP) was first prepared via photoinitiation reversible addition–fragmentation chain-transfer (RAFT) polymerization. PNIPAM networks increased imprinting site quantity and GO from reduction and flocculation. The flexible lamellar GO provided flexible two-dimensional nanosheets for fast transfer and improved imprinting site reachability. The larger maximum adsorption capacity (247.31 mg g–1) of ST-SMIP was 3 times larger than that of ST-SNIP (85.53 mg g–1) at 25.0 °C. The selectivity coefficient, k, and relative selectivity coefficient, k′, of ST-SMIP reached 7.98 and 8.59 for o-nitrophenol (o-NP), respectively, which exhibited a high selectivity of ST-SMIP. The low critical soluble temperature of ST-SMIP was 35.67 °C. The nondestructive desorption was accomplished by adjusting the ambient temperature as change of hydrophilicity and morphology of imprinted cavities, which overcame the trade-off effect between the great desorption effect and splendid selectivity.