Maximizing Headgroup Repulsion : Hybrid Surfactants with Ultrahighly Charged Inorganic Heads and Their Unusual Self-Assembly

Abstract

Non-equilibrium states of matter are arousing huge interest based on outstanding possibilities to generate unprecedented structures with novel properties. Self-organizing soft-matter is the ideal object of study as it unifies periodic order and high dynamics. Compared to settled systems it becomes vital to realize more complex interaction patterns. A promising and intricate approach is implementing controlled balance between attractive and repulsive forces. We try to answer a fundamental question in surfactant science: How are processes like lyotropic liquid crystals and micellization affected, when head group charge becomes so large that repulsive interactions are inevitable? A particular challenge is that size and shape of the surfactant must not change. We could realize the latter by means of new hybrid surfactants with a heteropolyanion head [EW11O39]n- (E = PV, SiIV, BIII; n = 3, 4, 5). Among the unusual self-assembled structures we report about micelles of a new type with dumbbell morphology.