Establishing Independent Tunability of the Mechanical and Transport Properties of Polymer Gels
Polymer gels can be used in the fabrication of materials for filtering liquid and gaseous media, solid-state electrolytes, and transdermal medical patches. This diverse range of applications primarily relies on the transport and mechanical properties of polymer gels. Both sets of properties have shown excellent tunability, but typically in a coupled fashion. Establishing the independent tunability of the transport and mechanical properties of polymer gels (using simple, cost-effective methods) is paramount if polymer gels are to be used to their full potential. Specifically, block copolymer gels self-assemble into organized nanoscale networks within the gel solvent, which allows for facile control of material properties. Mechanical properties can be tuned by altering gel network connectivity, which does not have an effect on solute transport rate. Solute transport rate is affected by polymer concentration and solvent choice. Two formulation methods were used in this work to independently tune the mechanical and transport properties of block copolymer gels. Gel mechanical behavior was tuned independently of solute transport rate via exchanging triblock and diblock copolymers (to change network connectivity) at constant polymer concentration. Solute transport rate was tuned independently of mechanical behavior by editing solvent viscosity.