Solvent-Induced Self-Assembly of Triblock Copolymers for Creating Polymer Nanocomposite Gels

The self-assembly of ABA triblock copolymers has been a focus of many studies over the years because of their possible applications in thermoplastic elastomers, solid electrolytes, and drug delivery systems. Triblock copolymers exhibiting ABA-type polymer architectures will self-assemble into either flower-like micelles or physically-crosslinked gel networks when added to B-block selective solvent. Although the two final states, micelles and gels, are well-established, controlling the self-assembly process to design specific nanostructures, while incorporating inorganic nanoparticles has yet to be fully established. Here, we present a recently developed method for creating nanostructured nanocomposite hydrogels by quickly injecting a solution containing ABA amphiphilic triblock copolymers and hydrophobic nanoparticles into water. During the ABA polymer/nanoparticle solution injection process, the nanoparticles aggregate within the physically-crosslinked hydrophobic A-block domains. By adding hydrophobic gold nanoparticles to the initial polymer solution, we are able to incorporate plasmonic properties into the nanostructured gels. The research presented here highlights the great potential in kinetic manipulation of self-assembled structures for making polymer nanocomposite gels.