Viscosity B coefficients of some alkyltrimethylammonium bromides and the effect of added alkan-1-ols
Abstract
The viscosity B coefficients for aqueous solutions of alkyltrimethylammonium bromides and decyltrimethylammonium bromide containing various concentrations of aliphatic alcohols have been determined at 25 °C. Viscosity B coefficients for the alkyltrimethylammonium bromides were positive and increased as the alkyl chain length increased; the B coefficient increase per methylene group was 0.084. The addition of aliphatic alcohols decreased the viscosity B coefficient of decyltrimethylammonium bromide. As the alcohol concentration was increased the measured partial molal volume Vs of decyltrimethylammonium bromide first decreased and then increased, and this was correlated with the viscosity B coefficient. The addition of alcohol is thought to effect the solvent structure and solute–solvent interactions by changing the composition and dielectric constant of the environment.