Termodinamika reakcija micelizacije natrijeva dodecil-sulfata u miješanim otapalima propan-1,2-diol - voda

Surfactant´s micellization behavior is very interesting to researchers due to numerous applications in various fields such as cosmetics, pharmaceuticals, detergents, etc. The phenomenon of surfactant aggregation has been studied in various solutions such as water, nonpolar and polar solvents, electrolytes and solvent mixtures. Research in various solvent mixtures is essential in order to obtain a better insight into the microscopic behavior and improve the performance of surfactants with emphasis on c.m.c and thermodynamics of the micellization reaction and to optimize the properties of solutions in various commercial applications. The presence of a polar organic solvent as an additive can significantly affect the thermodynamic properties of the micellar colloid of the ionic surfactant in water. Glycols are alcohols with two hydrophilic -OH groups and a hydrophobic carbon chain group, and both groups are capable to interact with ionic surfactants in solution when present in a mixture with water. In this thesis, the influence of the propylene-glycol/water mixture on the micellization reaction of SDS was conductometrically investigated with a focus on the influence of the alkyl chain length, temperature and glycol concentration. Then, from the temperature dependence of the measured parameters, the thermodynamics of this process was calculated, which includes both enthalpy and entropy contribution according to the standard Gibbs free energy of micellization.