Influence of Regio-Configuration on the Phase Diagrams of Double-Chain Giant Surfactants

Abstract

It has been established that a minute difference of the primary chemical and topological structures influences the self-assembly behaviors of giant surfactants; however, the regio-configuration effect has been rarely reported. Herein, we report a systematic study on the self-assembly behaviors of a series of double-chain giant surfactant regio-isomers, which consist of a hydrophilic polyhedral oligomeric silsesquioxane (POSS) head and two identical hydrophobic polystyrene (PS) tails with various molecular weights tethered in para-, meta-, and ortho-configurations, respectively. Small-angle X-ray scattering and transmission electron microscopy characterizations have been combined to investigate the phase behaviors of each sample and construct the phase diagrams for the three isomers with respect to the molecular weights of PS tails. It is observed that the regio-configuration significantly impacts the self-assembly behaviors of the giant surfactant isomers, including order-to-disorder (ODT) and order-to-or...