Solution Properties of Sulfate-Type Fluoro-Hybrid Anionic Surfactants with a Benzene Ring in Their Molecules

Abstract

We have so far synthesized sulfonate-type fluorohybrid anionic surfactants and investigated their solution properties(1). As a result, some of the sulfonatetype hybrid surfactants were found to allow dense aqueous solution to spread on the surface of less dense liquid and to be able to pseudo-emulsify three kinds of liquids with different properties such as hydrocarbon oil / water / fluorinated oil(1,2). Moreover, the hybrid surfactants with a C 4 fluorocarbon chain and hydrocarbon chains of different lengths showed no change with their concentration in the structure of micelle interior, whereas those with a C 6 fluorocarbon chain and hydrocarbon chains of different lengths exhibited a change in the structure of micelle interior with increase in their concentration(3). Thus, this peculiar behavior of the hybrid surfactants was shown to be remarkable when the lengths of fluorocarbon and hydrocarbon chains were suitably chosen. In order to examine the effect of the chemical structure of hybrid surfactants on their solution properties, sulfate-type, instead of sulfonate-type, fluoro-hybrid anionic surfactants with a benzene ring in their molecules that are hydrolysis-resistant were then Abstract: Two novel sulfate-type fluoro-hybrid anionic surfactants with a bezene ring in their molecules, F8H3OS and F6H5OS, were synthesized and their solution properties were investigated. Both of the hybrid surfactants were found to show an outstanding surface and interfacial tension lowering ability. F8H3OS formed compact micelles with small aggregation numbers and the micelles coagulated with increase in the surfactant concentration, while F6H5OS formed micelles at its low concentration and the micelles were transformed into vesicles at high concentrations of the surfactant.

Synthesis and properties of gemini-type hydrocarbon–fluorocarbon hybrid surfactants

“…The present authors succeeded in 1995 in synthesizing sulfonate-type hybrid surfactants with a fluorocarbon chain and a hydrocarbon chain as hydrophobic groups and having a -C 6 H 4 CO-group (C 6 H 4 = pphenylene) between the hydrophobic and hydrophilic groups as spacer, F(CF 2 ) m C 6 H 4 COCH(SO 3 Na)(CH 2 ) n H, FmHnS. These novel surfactants permitted us to co-emulsify mutually immiscible hydrocarbon oil and fluorocarbon oil in water, form long life micelles, and prepare highly viscoelastic gel-like liquid, all of which were impossible with the conventional surfactants [4][5][6][7][8][9][10][11][12][13]15]. Because of their very high Krafft points (48 8C for F6H6S, 98 8C for F8H6S), however, an improvement in their solubility in water had to be made.…”