Adsorption of Dinonyl-Naphthalene-Sulfonate on Carbon Black in the Presence of Polar Compound

Abstract

The adsorption of alkaline-earth metal salts of dinonyl-naphthalene sulfonic acid(DNNS) on carbon black was studied in a three-component system consisting of Solvent I (n-heptane), Solvent II (polar compounds and others), and DNNS in which the influence of Solvent II was investigated. The adsorption of DNNS is influenced by the kind of Solvent II used. The amount of adsorbed DNNS on carbon black decreases sharply with increasing amount of polar solvent, particularly, in the range of low fractions of the solvent. Non-polar solvents exert mild degrees of influence. Similar phenomenon was observed in the actual diesel engine sludge. There is a trend in the influence on adsorption of BaDNNS by polarity and by solubility parameters of the solvent II used. An isotherm equation for competitive adsorption was derived from the equilibrium theory and found that it was applicable to the data obtained in the present three-component system. Dispersancy of carbon black particle correlates with the amount of adsorbed BaDNNS at low concentrations of 1-propanol.