ADSORPTIVE MODIFICATION OF DIFFERENT SURFACES WITH AQUEOUS SOLUTIONS OF NEW SURFACTANTS

Abstract

The purpose of this work was investigating the wettability of different surfaces by water solutions of maleic acid derivative surfactants and establishing correlations between their colloid-chemical properties. The well-known methods for synthesis and determining the properties of surfactants were used in the work. The contact angles of surfactant water solutions on different hydrophilic and hydrophobic surfaces were investigated. It was established that the contact angles of surfactant water solutions on the hydrophilic surfaces (steel, glass) significantly depends on the composition and structure of surfactant molecules. It was shown, that more hydrophilic groups in the surfactant composition, higher the contact angle and at low surfactant concentrations, the hydrophobization of glass and metal surfaces take place. At high surfactant concentrations, the contact angles sharply decreased due to the fact that during adsorption, the surfactant molecules are oriented by the polar group to the surface. The concentration dependence of the contact angle passes through a minimum only for hydrophilic surfaces (glass, steel) as a monolayer of surfactant molecules is formed on the hydrophilic surface with orientation by polar groups to the solid surface. It has been established that the increase in the cosine of the contact angle at higher surfactant concentrations is associated with the hydrophilization of the surface due to the formation of micelles on surfaces. For a hydrophobic surface (paraffin), the cosine of the contact angle increases monotonically with an increase in the surfactant concentration. It has been established that the effect of the surfactant structure on the adsorptive modification of surfaces occurs only at low surfactant concentrations by the formation of a monolayer.