Selective Janus Particle Assembly at Tipping Points of Thermally-Switched Wetting

摘要

Thermal wetting can simply, selectively and rever-sibly join patchy particles into clusters (2D and 3D) and also colloidal crystals over the narrow temperature range of1-2 "C. This is demonstrated with Janus particles (gold half-coated silica spheres) immersed in a binary mixture of water/2,6-lutidine, such that the relative strength of gold-gold bonding through hydrophobic interaction and silica-silica bonding through the wetting-induced attraction is reversibly switched according to temperature.