title: Composite structure of temperature sensitive chitosan microgel and anomalous behavior in alcohol solutions.
abstract: Poly(N-isopropylacrylamide)/chitosan (PNIPAM/CS) core-shell microgel was synthesized by graft copolymerization. The microstructure of copolymers was characterized by FT-IR spectrum and (1)H-nuclear magnetic resonance ((1)H NMR). Transmission electron microscope (TEM) and dynamic light scattering (DLS) measurements display that the microgel has high monodispersity and with a core-shell structure. For swelling the microgel in various alcohol solutions, the particles first shrink; then flocculation occurs resulted from weak aggregation of particles with the increase of alcohol concentration. The investigation of the size of microgels as a function of temperature shows that the thermo-sensitive property is markedly exhibited when the alcohol concentration is low, and vanishes when the alcohol concentration exceeds some value where the microgels have the lowest size.
authors.affiliation: State Key Laboratory of Chemical Engineering and Department of Chemistry, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Weijun
authors.initials: W
authors.lastname: Liu
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Huang
authors.forename: Honglai
authors.initials: H
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Hu
mesh_terms: D000438:Alcohols / Q000737:chemistry*; D002625:Chemistry, Organic / Q000379:methods; D048271:Chitosan / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D012542:Scattering, Radiation; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature
chemical_list: D000438:Alcohols; D005782:Gels; D013501:Surface-Active Agents; D048271:Chitosan