Reversible temperature-controlled gelation in mixtures of pNIPAM microgels and non-ionic polymer surfactant.

摘要: We investigate the reversible gelation of poly(N-isopropylacrylamide) (pNIPAM) microgels in presence triblock-copolymer (PEO-PPO-PEO type) surfactant. demonstrate that association these polymers with microgel particles at elevated temperature is responsible for gelation, due to responsive nature components. This highlighted by an increase apparent hydrodynamic diameter dynamic light scattering experiments, which only occurs above volume phase transition pNIPAM. The gels result shrink over a time period much larger than collapse pNIPAM microgels, and retain shape container they form in. mechanism leads this structure result. Confocal microscopy experiments show both are present gel network, indicating associative gelation. vary particle architecture further process, find cross-link distribution plays key role mechanism, where uniformly cross-linked not observed. shows fuzzy corona involved polymers, allowing penetrate outer bridge particles. observed close physiological conditions, so have potential use biomedical applications, including tissue engineering.