Aim: The micellization behavior of cationic surfactants has been studied in the
presence of food additives.
Objectives: Micellization behaviour of cationic surfactants, Cetyltrimethylammonium
Bromide (CTAB) and Tetradecyltrimethylammonium Bromide (TTAB) has been studied
in water and in various concentrations of salts (food additives) L-glutamic acid, sodium
propionate, sodium citrate tribasic dihydrate and disodium tartrate dihydrate at (298.15,
308.15 and 318.15) K.
Methods: Two methods used in the present study are specific conductance measurements
and spectroscopy (NMR) studies.
Results: From the specific conductance(κ), various parameters such as Critical Micelle
Concentration (CMC), degree of ionization of micelle (α), standard Gibbs free energy
(ΔG°m), enthalpy (ΔH°m), and entropy (ΔS°m) of micellization have also been calculated.
Thermodynamic parameters related to the micellization process were also analyzed
through NMR studies.
Conclusion: The CMC values are influenced by the presence of food additive. The magnitude
of CMC values increases with an increase in the concentration of food additive. In all
the cases, enthalpy of micellization, ΔH°m values are found to be negative, whereas entropy
of micellization, ΔS°m values are positive, which indicates that hydrophobic interactions
play a major role in the micellization process. Moreover, NMR studies reveal that tartrate
and citrate are more hydrated than glutamic acid and propionate, resulting in a more downfield