Investigation of organic amine derivative adsorption at the interfaceof pigment and air

Abstract

In systems based on bituminous film-forming agents, the adsorption of a surfactant AC-1 at the interface with air and aluminum powder has been studied. The effect of temperature, quantitative contents of the film-forming and initial surfactant concentration on the parameters and mechanism of AC-1 concentration on the interface has been established. The equilibrium indicators of the adsorption of surfactant AC-1 at the interface between the film-forming agent and air were determined (limiting adsorption Г∞, thickness of the adsorption layer δ of the surfactant AC-1 group, landing area S of the functional group of AC-1 surfactants). A decrease in Г∞in 1.5-2.0 times (0.91∙ 10-5mol/m2 with Ĉs = 1.78) and δ (2.80∙10-9÷3.00∙10-9 m) with an increase in temperature from 280 to 310K and solvent concentration up to Ĉs = 1.78. The area S of the occupied amino group in the adsorption layer was 8.50 ∙ 10-20÷10.00 ∙ 10-20 m2. The value of the resulting thermal effect (ΔН) for bituminous compositions with Ĉs = 1.17÷1.78, regardless of the surfactant content, is plus 38-40 kJ/mol;for compositions with a solvent content of 1.78 (ĈSAA = 0.06) with an increase in temperature from 300 to 313 K, there was a decrease in the resulting adsorption index by 1.0 ∙ 10-6mol/m2 and ΔH to a level of 20÷1.5 kJ/mol2.A proportional increase in the adsorption of AC-1 on aluminum powder from the initial concentration of surfactants and an insignificant decrease in the adsorption index in systems more concentrated in bitumen were established.