INFLUENCE OF SURFACTANTS ON THE ADSORPTION OF METHYL LINOLENATE

Abstract

Adsorption of methyl linolenate on activated granular carbon and on glass powder in methanol water medium was studied by spectrophotometry. The methanol percentage of the solution was determined from turbidity measurements of methyl linolenate in aqueous medium and in the presence of surfactants. S-type adsorption isotherm of methyl linolenate was observed at 18-degrees-C on activated granular carbon in 28.57% methanol-water mixture. This indicates strong intermolecular attraction and perpendicular orientation to the surface. Effect of surfactants (anionic, cationic, nonionic) having identical hydrophobic group, i.e. C12H25) on the adsorption phenomena, at the concentration below. CMC (2.10(-5)M) was studied. Surfactants influenced both adsorption rate and adsorption equilibrium for a certain (mol surfactant/mol methyl linolenate) ratio range (0.02-0.06). While anionic surfactants decreased the amount of adsorbed methyl linolenate, the cationic and nonionic ores increased it. Maximum effect was observed at the 0.03 ratio.