Contact angles of quartz by capillary penetration of liquids and captive bubble techniques

Contact angles of quartz particles were calculated from the ratios of particle wetting rates of water (polar) and toluene (non-polar) through compact particle beds, contained in capillaries (capillary penetration of liquids). For comparison, the contact angles were also measured on a prepared quartz surface by the captive bubble technique. Both methods are significantly different in their principles of measurement and in this paper emphasis is laid on the technique of capillary penetration of liquids. Floatabilities were tested to confirm the hydrophobicities of quartz particles. Variables in this study include pH, hydrocarbonic chain length and concentration of the collector because amine concentration and pH are important variables for the hydrophobicity of quartz. Zeta potentials were also measured.