Temperature responsive binary gelation of pNIPAM microgels and a neutral triblock-copolymer surfactant.

SANS will be used to study the structure of an adsorbed polymermic surfactant on pNIPAM microgels. It has been observed that when mixtures of pNIPAM microgels and triblock-copolymer surfactant are heated above the volume phase transition temperature of pNIPAM, the sample transitions from a liquid to a gel. This transition is fully reversible. We have demonstrated that the gelation is a result of the association of the polymers at elevated temperatures, however the nature of the association is unclear. We aim to use SANS to reveal the structure of the adsorbed polymer, to elucidate whether the gel network results from polymer micelles bridging the microgel particles, or whether the surfactant penetrates inside the microgel periphery and this results in gelation. This study will ultimately lead to a greater understanding of this binary gelation and aid with future design of these systems.