Behavior of thermo-sensitive gel in polymer solution

Particles of a thermo-sensitive gel were observed in a polymer solution. Gels of N-isopropylacrylamide (NIPA), which generally have a volumetric transition temperature of around 32 °C in pure water, were synthesized as porous media. The swelling ratio, mass ratio of a gel in the swollen state to that in the dry state, was measured in water as well as in an aqueous polymer solution of polyacrylamide at various temperatures. The observation in the polymer solution, where temperatures varied vertically between 10 °C and 40 °C from bottom to top, showed that gel particles repeatedly moved up and down.