title: Effect of polyoxypropylene chain length on the critical micelle concentration of propylene oxide-ethylene oxide block copolymers.
abstract: In this work, the surface activity of block copolymer nonionic surfactants (RPE) has been determined, i.e., critical micelle concentration (CMC), surface excess concentration (gamma), surface area demand per molecule (A), surface tension at CMC (gamma(CMC)). A linear decrease of ln[CMC] vs number of oxypropylene units in copolymer molecule was observed. The change in the work of cohesion per oxypropylene group when passing from molecular into micellar state, calculated from the Shinoda equation, was 0.43 kT for the studied compounds.
authors.affiliation: Department of Chemical Engineering, Zhejiang University, Hangzhou 310027, China. zhiguozhang2004@yahoo.com.cn
authors.forename: Zhi-Guo
authors.initials: ZG
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Yin
mesh_terms: D003102:Colloids / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry*; D005027:Ethylene Oxide / Q000737:chemistry*; D008422:Materials Testing; D008823:Micelles; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry; D013329:Structure-Activity Relationship; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D003102:Colloids; D004852:Epoxy Compounds; D008823:Micelles; D011108:Polymers; D013501:Surface-Active Agents; D005027:Ethylene Oxide; C009068:propylene oxide