Fluorinated surfactants introduction

Unlike mixed hydrocarbon-chain surfactants of similar molecular structure, mixtures of fluorinated surfactants and hydrocarbon-chain surfactants do not behave ideally, even when the surfactants have a similar hydrophilic group. Mixtures of anionic fluorinated surfactants with anionic hydrocarbon surfactants exhibit a positive deviation from the ideal relation (Fig. 7.4). In contrast, surfactant mixtures containing a nonionic surfactant or oppositely charged ionic surfactants exhibit a negative deviation from ideal predictions. The formation of mixed micelles is governed by hydrophobic interactions between hydrocarbon and fluorocarbon chains and electrostatic effects [66]. Introduction of nonionic surfactants into micelles of anionic fluorinated surfactants reduces electrostatic repulsion between the ionic head groups. Apparently, the resulting electrostatic effect overcomes the hydrophobic interaction between the fluorocarbon and hydrocarbon chains. 

This chapter is an introduction to industrial- and laboratory-scale syntheses of surfactants derived from fluorinated intermediates obtained by electrochemical fluorination. The chemistry involved in the preparation of these compounds has been established for many decades and, because of its confidential nature, is mostly described in the patent literature. Recent interest in the... 

Rosen [35] has tabulated values of Tm for a wide variety of anionic, cationic, non-ionic and zwitterionic surfactants and has discussed the effect of surfactant structure on With hydrocarbon surfactants, the length of the hydrophobic group has little effect except when this exceeds 16 carbon atoms when a significant decrease in r jis noted, possibly due to coiling of the chain. Chain branching has only a small effect on T j, as has introduction of fluorine atoms into the hydrophobic chain. With polyoxyethylene non-ionic surfactants of fixed oxy-ethylene chain length the value of appears to be little influenced by the length of the hydrocarbon chain. 

The effect on micellar properties of the introduction of a fluorine atom into the hydrocarbon chain has been investigated. Muller et al [24-27] reported that substitution of the CF3 group for the terminal CH3 group of the surfactants... 

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