Self-association of n -hexyltrimethyl-ammonium bromide in aqueous electrolyte solution
The self-association of n-hexyltrimethylammonium bromide (C6TAB) in aqueous solution has been studied by static and dynamic light scattering and NMR spectroscopy at 25 °C in the presence of added electrolyte, and critical aggregation concentrations, aggregation numbers and the degree of ionization have been calculated. Aggregation numbers determined from light scattering and from the application of mass-action theory to the concentration dependence of 1H NMR chemical shifts of four protons along the alkyl chain of C6TAB, were between three and four over the range of electrolyte concentration studied (0.2–0.7 molkg−1 NaBr). A structure for the small aggregates has been proposed from the NMR chemical shift data.
Unable to display preview. Download preview PDF.