SURFACTANT STRUCTURE-PROPERTY RELATIONSHIP: ALIPHATIC ALCOHOLS AND BUBBLE RISE VELOCITY

摘要

This study is part of our investigation into the frother structure-property relationship, focusing on aliphatic alcohols. The structure variation is the length of the alkyl chain (C4 to C7), and position of the methyl branch (-CH3) and Hydroxyl (-OH) group in five- and six-carbon alcohols. The property was bubble rise velocity. Single bubble velocity profiles were determined in a 350 cm column. Velocity at 300 cm as a function of concentration is determined and the concentration to reach minimum velocity at 300 cm (CMV) estimated. The effect of increasing alkyl chain length is to decrease CMV by about one order of magnitude for every one carbon addition in the molecule; the CMV decreases as the methyl branch moves away from the hydroxyl group; and the CMV increases as the OH moves from position 1 to 3 (i.e., to the centre of the molecule). An argument based on surfactant molecule packing on the bubble surface is proposed to account for the effect on CMV.