STRUCTURAL CHANGES OF SURFACTANT INDUCED BY NONCRYSTALLINE AMPHIPHILIC DIBLOCK COPOLYMER

摘要

@@Mixed amphiphilic systems, in particular mixture of low-molecular-weight surfactant and amphiphilic block copolymer, are technically important because the mixture systems provide a way of tailoring microdomain properties through simple composition variations; new structures may thus be obtained by changing the system composition, rather than through synthesis of new materials.Important technical applications based on such mixed systems include various industrial and technological fields such as cosmetics and pharmaceutical products, paints and coatings, and materials for biotechnology. The systems incorporating both high and low molecular weight amphiphiles in water or aqueous media have been intensively investigated both experimentally and theoretically.Up to now, relatively little was known about ternary systems of amphiphilic block copolymers and low-molecular-weight surfactants in organic solvent as well as the solid films cast from these ternary-system solutions, despite the widespread use of amphiphilic block copolymers or lipophilic surfactants as emulsifiers, stabilizers and phase transfer agents for the preparation of various metal nanoparticles in organic solvents. In this work, we investigated the solid films cast from organic solutions consisting of the lipophilic low-molecularweight surfactant tetraoctylammonium bromide (TOAB) and the amphiphilic noncrystalline diblock copolymer [(poly(styrene-6-acrylic acid) or partly hydrolyzed poly(styrene-b-n-butyl acrylate)] in organic solvents. TOAB, a four-tail surfactant, is widely used as stabilizer and phase transfer agent for the preparation of metal nanoparticles in organic solvents.