Aqueous behaviour of cationic surfactants containing a cleavable group

The aggregation behaviour of two novel cationic RAFT agents (transfer surfactants); N,NN,N-dimethyl-N-(4-(((phenylcarbonothioyl)thio)methyl)benzyl)ethanammonium bromide (PCDBAB) and N  -(4-((((dodecylthio)-carbonothioyl)thio)methyl)benzyl)-N,NN,N-dimethylethanammonium bromide (DCTBAB) in diluted solutions have been investigated by surface tension, conductimetry and microcalorimetry measurements. The thermodynamic parameters i.e. the critical micelle concentration (cmc), the degree of micelle ionization (α  ), the head group surface area (a0a0), ΔHmicΔHmic, ΔGmicΔGmic and TΔSmicTΔSmic are reported at 303 K. The thermodynamic parameters have been compared to those of the conventional surfactant cetyltrimethylammonium bromide (CTAB) in order to specify structural relationships. The obtained results have been discussed considering the hydrophobic behaviour of the SCS linkage and the specific interactions that arise from the introduction of the benzene ring into the hydrophobic part.

Two cationic RAFT agents (transfer surfactants) have been synthesized and their aggregation behaviour has been investigated in diluted solutions by surface tension, conductimetry and microcalorimetry measurements.Figure optionsDownload as PowerPoint slide