Proton Chemical Exchange in Aqueous Solutions of Dodecylammonium Chloride: Effects of Micellar Aggregation

摘要

Proton chemical exchange was studied in aqueous solutions of dodecylammonium chloride (DDAC1) for two selected concentrations,18 and 33 wt%.The Fourier transform Carr-Purcell-Meiboom-Gill (CPMG) NMR method combined with the Carver and Richards model for T2 dispersion curve analysis were employed to evaluate the temperature dependence of the proton exchange rates k_(ex).An increase of the energy barrier height DELTAG for the proton chemical exchange between water and ammonium cation (-NH3~+) was observed as the DDAC1 concentration was increased.Results are complementary to previous studies of aggregation phenomena for various n-alkylammonium chlorides.