标题：Stimuli-ResponsiveShape Switching of Polymer Colloids by Temperature-Sensitive Absorption of Solvent
作者：Huaguang Wang1,Binghui Li1, Arjun G. Yodh, 2 and Zexin Zhang1
The dynamicmanipulation of colloidal particle shape offers a novel design mechanism forthe creation of advanced responsive materials. To this end, we introduce aversatile new strategy for shape control of anisotropic polymeric colloidalparticles. The concept utilizes temperature sensitive absorption of a suitablesolvent from a binary mixture. Specifically, increasing the temperature in thevicinity of the demixing transition of a binary mixture causes more solvent tobe absorbed into the polymeric colloidal particle, which, in turn, lowers theglass transition temperature of the polymer inside the particle, with aconcomitant decrease in viscosity. The balance between the internal viscosityand surface tension of the particle is thus disrupted, and the anisotropicshape of the particle shifts to become more spherical. Subsequent rapidtemperature quenching can halt the process, leaving the particle with anintermediate anisotropy. The resultant shape anisotropy control provides newroutes for studies of the phase transitions of anisotropic colloids and enablesthe fabrication of unique particles for materials applications.