Adsorption and aggregation properties of alkoxy-group-modified homogeneous polyoxyethylene alkyl ether nonionic surfactants

Publication date: 15 June 2019Source: Journal of Molecular Liquids, Volume 284Author(s): Shiho Yada, Toshiyuki Suzuki, Satoru Hashimoto, Tomokazu YoshimuraAbstractThe development of new surfactants with interesting properties and new functionalities that can be controlled in a simple manner is an important industrial objective. Herein, we report the synthesis of homogeneous polyoxyethylene (EO) alkyl ether nonionic surfactants modified with alkoxy groups (C12EO8OR, where C12 and EO8 are dodecyl and octaoxyethylene chains, respectively, and R = Me and Et) from a homogeneous EO-type hexaoxyethylene dodecyl ether (C12EO6) and diethylene glycol monomethyl ether or diethylene glycol monoethyl ether. The adsorption and aggregation properties of these surfactants were characterized through cloud point and surface tension measurements, and by small-angle X-ray scattering, polarization microscopy, and cryogenic transmission electron microscopy; these properties were compared to those of previously reported homogeneous EO-type (C12EO8) and polyoxypropylene-polyoxyethylene type surfactants (C12EO8POy, y = 1, 2, 3). The introduction of a methoxy or ethoxy group at the terminus of the EO chain in C12EO8 resulted in an increase in hydrophobicity and a greatly reduced cloud point. Substitution of the terminal hydroxy group of the EO chain in C12EO8 with methoxy and then ethoxy led to increasingly lower surface tensions in solution and more efficient air/water interfacial adsorption....
Source: Journal of Molecular Liquids - Category: Molecular Biology Source Type: research