Interaction of hexadecylpyridinium bromide with glycine in aqueous medium using the Krafft temperature from conductivity measurement

Abstract

Conductivity measurements were employed to investigate Kraft temperature (TK) of aqueous solution of hexadecylpyridinium bromide (HPyBr) and HPyBr+glycine with added counter-ions. The pseudophase ion exchange model was adopted for HPyBr in pure water, glycine (Gly) and potassium bromide (KBr). The TK values for HPyBr increase with the increase in concentration of Gly and KBr. However, the experimental results show that the degree of counter-ion dissociation or ionization (α) remains nearly constant as the total surfactant concentration or counter-ion concentrations of salt are varied at the slower rate of micellar growth. Although the (α) is dependent on micellar shapes and changes as the micellar shape changes. The TK measurements for ionic micelles can be used to estimate counter-ion dissociation (α). The TK increase with increase in the counter-ion concentration because the solubility of surfactant is reduced at faster rate than critical micellar concentration (CMC). Kraft temperature measurements were employed to find the interaction between HPyBr and Glycine.