title: Cleavable surfactants to tune the stability of W/O miniemulsions.
abstract: Recently, there has been growing interest towards the formation and use of miniemulsions as nanoreactors for polymerization and precipitation reactions. Regarding precipitation reactions in miniemulsions, emulsifiers are required that on the one hand stabilize droplets in a size range <1 μm and on the other hand allow break-up of the miniemulsion into its two initial phases after particle synthesis for purification reasons. In this work we report the synthesis and emulsifying abilities of low-mass cleavable emulsifiers based on monoesters of oxalic and malonic acids for the stabilization of water-in-oil miniemulsions. A systematic screening of compounds with respect to different polar groups as well as length, molecular branching and type of alkyl chains and their suitability as emulsifiers was performed. Our results show that the size of droplets stabilized by these emulsifiers strongly depends on the nature of the polar group and the length of the lipophilic chain. The targeted phase separation of the emulsions was triggered by the addition of a base cleaving the emulsifiers.
authors.affiliation: Institute of Organic Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Belenki
authors.forename: M
authors.initials: M
authors.lastname: Winkelmann
authors.forename: M
authors.initials: M
authors.lastname: Nieger
authors.forename: W
authors.initials: W
authors.lastname: Gerlinger
authors.forename: B
authors.initials: B
authors.lastname: Sachweh
authors.forename: H P
authors.initials: HP
authors.lastname: Schuchmann
authors.forename: T
authors.initials: T
authors.lastname: Muller
authors.forename: S
authors.initials: S
authors.lastname: Bräse
mesh_terms: D004655:Emulsions / Q000737:chemistry; D008314:Malonates / Q000737:chemistry; D015394:Molecular Structure; D009821:Oils / Q000737:chemistry*; D019815:Oxalic Acid / Q000737:chemistry; D013501:Surface-Active Agents / Q000138:chemical synthesis / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D004655:Emulsions; D008314:Malonates; D009821:Oils; D013501:Surface-Active Agents; D014867:Water; D019815:Oxalic Acid; C030290:malonic acid