title: Effect of thermal cycling on the properties of thermoresponsive poly(N-isopropylacrylamide) hydrogels.
abstract: Crosslinked poly(N-isopropylacrylamide) hydrogels have been widely studied for a variety of thermoresponsive applications, including chromatography, affinity precipitation, controlled biocatalysis, viable cell immobilisation, biomimetic actuators and, in particular, modulated drug delivery. The exploitation of crosslinked poly(N-isopropylacrylamide) hydrogels in all these applications relies on the well-known temperature-sensitive swelling properties of these hydrogels. The purpose of the current study was to determine the effects of repeated thermal cycling on the thermoresponsive swelling behaviour of crosslinked poly(N-isopropylacrylamide) hydrogels. The results show that repeated thermal cycling leads to the formation of cracks on the surface of the hydrogels. Repeated thermal cycling also results in a decreased degree of swelling in the crosslinked poly(N-isopropylacrylamide) hydrogels at temperatures below the volume phase transition temperature (VPTT).
authors: School of Pharmacy & Pharmaceutical Sciences, University of Manchester, Manchester, M13 9PL, UK.
authors: Sai Kit
authors: SK
authors: Li
authors: Antony
authors: A
authors: D'Emanuele
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning / Q000295:instrumentation / Q000379:methods; D011232:Chemical Precipitation; D002845:Chromatography; D003692:Delayed-Action Preparations; D004055:Differential Thermal Analysis / Q000379:methods; D006358:Hot Temperature; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods; D008422:Materials Testing; D011108:Polymers; D013696:Temperature; D013816:Thermodynamics
chemical_list: D000180:Acrylic Resins; D003692:Delayed-Action Preparations; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate