Seeing the unseen dynamics in soft matter

The theme of this thesis concerns the fundamental questions in soft matter, in particular, the dynamics of vesicle membranes, interfacial polymers, colloidal particles. Optical imaging was applied three distinct systems to reveal the underlying physical processes that were hindered by other prior indirect measurements. First, mechanical responses of both polymer and lipid vesicles were investigated by watching their shape transformations under environmental variations, mostly under osmotic shocks, which emitted new prospects on membrane elasticity, instability and kinetics. Furthermore, with statistical analysis of particle and pattern tracking, three classical questions in polymer physics regarding polymer-surface interactions were revisited: adsorption, surface diffusion, and dewetting. The final remark of this thesis presented inter-surface interaction induced by binary liquid mixture near the demixing temperature. Both colloidal assembly and physical chemistry of binary liquid were examined through Janus particle. All these studies followed the same spirit of using direct imaging to declare the unseen dynamical processes in soft matter