Sugar-responsive aggregates and temperature/redox-responsive hydrogels prepared by block copolymer self-assembly

摘要

Two different types of self-assembled polymeric structures will be discussed. Block copolymers with pendant boronic acid units proved capable of forming well-defined aggregates in aqueous solution and were susceptible to dissociation upon increasing pH or the introduction of low molecular weight diols (e.g., glucose). By incorporating boronic acid groups at polymer chain ends, reversible covalent three-arm stars were accessible via boroxine formation. Other types of responsive polymers were prepared as well, including triblock copolymers synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization that were capable of forming responsive hydrogels. The ABA triblocks contained outer thermoresponsive A blocks and a water-soluble B block that contained a trithiocarbonate at its midpoint. Following aminolysis of the gels formed at high temperature, thioldisulfide transformations allowed the materials to be both temperature-and redoxresponsive.