INFLUENCE OF SURFACTANT STRUCTURE ON WETTABILITY MODIFICATION OF HYDROPHOBIC GRANULAR SURFACES

Using the capillary penetration wetting technique, the influence of surfactant structure on wettability modification of hydrophobic granular surfaces was examined. Linear and branched hydrocarbon chain sulfates, 5 mol monodisperse ethoxylates and 5 mol monodisperse ethoxysulfates were used as surfactants and resin-coated sand as the hydrophobic granular surface. Both the surfactant type and hydrocarbon chain branching were observed to exert a significant influence on the rate and effectiveness of wetting. Wetting rates for ethoxylates > sulfates > ethoxysulfates. Wetting effectiveness for sulfates > ethoxylates. For a given surfactant type, hydrocarbon chain branching was observed to increase wetting rate and effectiveness. (C) 1994 Academic Press, Inc.