MICELLIZATION OF QUARTERNARY BASED CATIONIC SURFACTANTS IN TRIETHANOLAMINE-WATER MEDIA: A CONDUCTOMETRY STUDY

The effect of polar organic solvent, triethanolamine (TEA) on the micellization of a mixture of dodecyltrimethylammonium bromide (DETABr) and hexadecyltrimethylammonium bromide (HATABr) has been studied by conductance measurements at temperature range of 298.1 to 313.1K in steps of 5.1K. The values of the critical micelle concentration (CMC*) and the extent of counter-ion binding were obtained by fittings of the specific conductivity-concentration curve to the integrated form of the Boltzmann-Sigmoid equations. The values of CMC* was found to decrease with increase in the percentage composition of TEA. The degree of counter-ion binding of the mixed micelles (β) was determined from the ratio of the slopes corresponding to the post (A2) and pre-mixed micellar regions (A1). The thermodynamic quantities ( and ) was evaluated with the aid of the equilibrium model of mixed micelle formation. The negative deviation of the CMC* from the ideal system, the spontaneity, and the increased degree of randomness of the system were discussed on the basis of hydrophobic-solvophobic interactions of the monomers at elevated temperature

Equilibrium, Thermodynamics, Kinetics of Adsorption of CO32- and SO42- Ions on Modified Plantain Peels

<p><i><strong>Abstract</strong></i><strong>—</strong> <i>To reuse treated wastewater, water quality must be improved. Adsorption is a simple, cost-effective method for eliminating toxicities and poisnous anions. The adsorbent's features and properties determine the method's effectiveness. This research examines the adsorption of carbonate and sulphate anions onto plantain peels modified with 2-amino-4,6-dihydridoxypyrimidine. Characterization was done using SEM, XRD, and FTIR. UV-visible spectroscopy was used to measure initial and equilibrium concentrations, and Langmuir and Fremdliuch isotherms were used to analyze the data. The best parameters for adsorbing 150 mg/L CO32- and SO42- were: pH 2, and 4, 0.8 g adsorbent, 120 min contact time, and 330 K temperature. Kinetic study used pseudo-first-order reaction equations, and both ion uptake processes followed pseudo-first-order rate expression. ΔG (-3.772 kJ/mol) for CO32- and ΔG (-3.047 kJ/mol) for SO42- were negative, and ΔH (-22.04 kJ/mol) and (-39.92 kJ/mol) were also negative, indicating the adsorption process was feasible, spontaneous, and exothermic. Modified plantain peels had high adsorptivity and were a cost-effective adsorbent for CO32- and SO42- from aqueous solutions.</i></p&gt