The effect of long chain alkanes on adhesion between silica particles

Abstract

The destruction time of the sediment column structure of silica particles was measured using a simple device that was constructed in our laboratory. The measurements were carried out for different fractions of silica particles in alkanes from hexane to hexadecane. We have studied the correlations between the measured destruction time of the sediment column structure of silica particles and the bulk properties of silica particles and alkanes as well as alkane-air, silica particles-air and silica particles-alkane interfacial properties. On the basis of this study, linear relationships between the reciprocal of the destruction time and the average diameter of silica particle fractions, the work of alkanes cohesion, the difference between alkanes and silica densities, and the reciprocal of the free energy of interaction per alkane molecule were found. From these relationships, the critical (for infinitely long destruction time) particle diameter, the work of cohesion, the difference between silica particles and alkane densities and the reciprocal of the free energy of interaction per alkane molecule were determined. It was found that for the systems having critical values of the parameters mentioned above, the detachment force was equal to the attachment force, resulting from gravitational and interfacial interactions, respectively. It is also found from the present study that the attachment force between silica particles depends on the work of alkane cohesion and the work of adhesion between silica particles and liquid, and that the destruction of the sediment column structure of silica particles takes place as a result of disruption of the alkane film between two silica particles. The destruction time increased with the number of carbon atoms in the alkane molecule as a result of decreased detachment force and perimeter of the contact plane and increased attachment force between silica particles in alkanes.