title: Dynamics of amphiphilic diblock copolymers at the air-water interface.
abstract: Two polyisoprene-polyethyleneoxide diblock copolymers with different block length ratios adsorbed to the water surface were investigated by multiple angle of incidence ellipsometry, evanescent wave light scattering, and surface tension experiments. In a semidilute interfacial regime, the transition from a two-dimensional to a "mushroom" regime, in which polymer chains form loops and tails in the subphase, was discussed. A diffusion mechanism parallel to the interface was probed by evanescent wave dynamic light scattering. At intermediate concentrations, the interfacial diffusion coefficient D(∥) scales with the surface concentration Γ, as D(∥) ~ Γ(0.77) in agreement with the scaling observed for polymer solutions in a semidilute regime. At relatively high concentrations a decreasing of D(∥) is discussed in terms of increasing friction due to interactions between polyisoprene chains.
authors.affiliation: Max Planck Institute of Colloids and Interfaces, 14476 Potsdam-Golm, Germany. antonio.stocco@mpikg.mpg.de
authors.forename: Antonio
authors.initials: A
authors.lastname: Stocco
authors.forename: Klaus
authors.initials: K
authors.lastname: Tauer
authors.forename: Stergios
authors.initials: S
authors.lastname: Pispas
authors.forename: Reinhard
authors.initials: R
authors.lastname: Sigel
mesh_terms: D000327:Adsorption; D000388:Air; D004058:Diffusion; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D055620:Optical Phenomena; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D012996:Solutions; D013500:Surface Tension; D013501:Surface-Active Agents; D013729:Terpenes / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D011108:Polymers; D012996:Solutions; D013501:Surface-Active Agents; D013729:Terpenes; D014867:Water; D011092:Polyethylene Glycols