title: Temperature-dependent aggregation and disaggregation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer in aqueous solution.
abstract: Aggregation and disaggregation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers, Pluronics P103 and P104, in aqueous solutions during a heating and cooling cycle were investigated by dynamic laser scattering (DLS) and 1H NMR spectroscopy. Temperature hysteresis was observed by DLS when cooling the copolymer aqueous solutions because larger aggregates existed at temperatures lower than critical micellization temperature (CMT), but no temperature differences were observed by NMR. This phenomenon was explained as the forming of water-swollen micelles at temperatures lower than CMT during the cooling process.
authors.affiliation: Laboratory of Separation Science and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100080, China.
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Liang
authors.forename: Chen
authors.initials: C
authors.lastname: Guo
authors.forename: Junhe
authors.initials: J
authors.lastname: Ma
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Shu
authors.initials: S
authors.lastname: Chen
authors.forename: Huizhou
authors.initials: H
authors.lastname: Liu
mesh_terms: D007834:Lasers; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008970:Molecular Weight; D020442:Poloxamer / Q000737:chemistry*; D012542:Scattering, Radiation; D012996:Solutions; D013696:Temperature
chemical_list: D008823:Micelles; D012996:Solutions; D020442:Poloxamer