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Direct Observation Of Phase Transition Dynamics In Suspensions Of Soft Colloidal Hydrogel Particles, Jae Kyu Cho, Zhiyong Meng, L. Andrew Lyon, Victor Breedveld

Biology, Chemistry, and Environmental Sciences Faculty Books and Book Chapters

Due to the tunability of their softness and volume as a function of temperature, poly(N-isopropylacrylamide) (pNIPAm) hydrogel particles have emerged as a model system for soft colloidal spheres. By introducing AAc as comonomer, one can also tune the particle volume via pH. We report on the phase behavior of these stimuli-responsive colloids as measured with a microdialysis cell. This device, which integrates microfluidics with Particle Tracking Video-microscopy allows for simple and quick investigation of the phase behavior of suspensions the soft colloidal hydrogel as a function of pH as well as its packing density. In particular, we demonstrate the existence …