The Effect of Solvent Quality on Pathway-Dependent Solution-State Self-Assembly of an Amphiphilic Diblock Copolymer
Vivek M. Prabhu, Kenneth Mineart, Guangmin Wei, James Hedrick, Yi Yan Yang, Shrinivas Venkataraman
The cholesterol-functionalized polycarbonate-based diblock copolymer, PEG113-b-P(MTC-Chol)30, forms pathway-dependent nanostructures via dialysis-based solvent exchange. The initial organic solvent that dissolves or disperses the polymer dictates a self-assembly pathway. Depending upon the initial solvent, nanostructures of disk-like micelles, exhibiting asymmetric growth and hierarchical features are accessible from a single amphiphilic precursor. Dioxane and THF molecularly dissolves the block copolymer, but THF yields disks and dioxane stacked-disks. DMF and methanol display dispersed disks, then form stacked disk structure. The path-dependent morphology, correlated to solubility parameters, offers routes to tailor self-assemblies with limited sets of building blocks.