Temperature-Induced Critical Phenomenon of Hybrid Surfactant As Revealed by Viscosity Measurements

Abstract

We have recently found that sodium 1-oxo-1-[4-(tridecafluorohexyl)phenyl]-2-hexanesulfonate (FC6-HC4), one of the synthesized hybrid surfactants that have both fluorocarbon chain and hydrocarbon chain in the molecule, exhibits a thermoresponsive viscoelastic behavior in aqueous solution. The aim of this study is to examine the viscosity behavior in solution of synthesized surfactants with different chemical structures (different lengths of fluorocarbon and hydrocarbon chains) as a function of temperature and to analyze the data obtained by using a theory of probability. The study reveals the importance of the chemical structure in which the numbers of carbon atoms are 6 and 4 in the fluorocarbon and hydrocarbon chains, respectively, for the hybrid surfactant to show the thermoresponsive viscoelastic behavior. This behavior is also found to be observed during the process where the size of assemblies of surfactant molecules decreases with rising temperature and when the probability of collision is highest between small and large molecular assemblies.

Synthesis and Solution Properties of Sulfate-Type Hybrid Surfactants with an Ethylene Spacer

“…FmPHnS are expected to be a good emulsifier for making aqueous fluorocarbon paints because they are able to emulsify fluorocarbon/water/hydrocarbon systems (6). The present authors have also reported that the synthesized hybrid surfactants form long-life micelles detected by NMR (7) and abnormally highly viscous solutions at about 10 wt% and 36 (8)(9)(10)(11)(12), and have a human tooth reformability for the prevention of its decay (13). These properties are characteristic of the hybrid surfactants and cannot be developed by mixed systems of fluorocarbon and hydrocarbon surfactants.…”

“…We have reported a peculiar viscosity behavior of highly concentrated aqueous solutions of the hybrid surfactants (8)(9)(10)(11)(12). Figure 6 shows typical photographs of 1, 5, 10, and 20 wt% solutions of F8EH3OS at 25 .…”

Synthesis and Monolayer Behaviors of Novel Hybrid Corynomycolic Acids Containing Semifluoroalkyl Groups

“…The surface properties critical micelle concentration CMC , effectiveness of surface tension reduction g CMC , efficiency of surface tension reduction pC 20 Fig. 5a .…”

Thermo-responsive Wormlike Micelles

“…Yoshino et al [54] synthesized the fluoro-hybrid anionic surfactant FC6-HC4 by reacting l-[4-(perfluoroalkyl)phenyl]-l-alkanones with a sulphur trioxide/1,4-dioxane complex in 1,2-dichloroethane, followed by neutralization with aqueous sodium hydroxide, and then investigated its rheological behaviour as a function of temperature [6,54]. A thermo-thickening response was detected for concentrations ranging from 7 to 15 wt%; the viscosity peak and corresponding temperature could be tuned by varying surfactant concentration [6].…”