Nanostructural Evaluation of Styrenic Block Copolymer Gels Across a Diverse Formulation Parameter Space

The potential nanostructures of styrenic block copolymer gels have been shown to mimic those in pure block copolymers including lamellar, gyroid, cylindrical, and spherical morphologies. In pure block copolymers, the domain sizes within these various morphologies have been quantitatively linked to the copolymer's molecular characteristics, but a similar understanding has yet to be fully developed in block copolymer gels owing to a greatly expanded parameter space. The present study focuses on the size and spacing of spherical domains within gels wherein the styrenic blocks comprise the spherical domains and aliphatic blocks and an aliphatic-selective solvent comprise the continuous domain. Gels composed of triblock copolymers with different molecular weights and block compositions and at various concentrations will first be discussed. Next, gels containing pairs of styrenic block copolymers, including various triblock-triblock and triblock-diblock combinations, across a concentration matrix will be appraised. The structural results from all copolymer gels will be evaluated to determine if universal principles dictating domain sizes can be established.