Interfacial properties and emulsification in systems of perfluoropolyether/non-fluorinated oil/partially fluorinated oligomeric and polymeric compounds

Abstract

Abstract Interfacial properties and emulsification were studied in the systems perfluoropolyether (PFPE)/non-fluorinated oil (NFO)/partially fluorinated oligomeric or polymeric compounds (Rf-Rh). All the Rf-Rh compounds were synthesized. The polymeric Rf-Rh compounds were random and graft copolymers with 1 H ,1 H ,2 H ,2 H -heptadecafluorodecyl acrylate (17FA) repeating units introduced into a trunk polymer chain. The Rf-Rh compounds dissolved or dispersed in most NFOs, but did not dissolve in PFPE. They depressed interfacial tensions at PFPE-toluene interfaces, which were mainly used in this study, with an increase in their concentrations. The polymeric Rf-Rh compounds were effective emulsifying agents for the formation of macroemulsions. The graft copolymers permitted the formation of very stable emulsions w ith a droplet diameter of about 200 nm, in particular. No direct relationship was found between the depression of the interfacial tensions and the stability of the emulsions. However, low interfacial tensions and sterically stable protection of an adsorbed film served for the formation of small-sized emulsion droplets, which contributed to reduce the sedimentation due to the gravitational force.