Size-dependence hydrophobicity in nanocrystalline talc produced by high-intensity planetary ball milling

Abstract

ABSTRACTMicron-size talc samples were ground using a high-intensity planetary ball mill at different milling times as an attempt to reduce particle size and study the effect on the corresponding hydrophobicity. XRD and SEM results confirmed the decrease in the particle size. FTIR spectroscopy analyses revealed the talc characteristic bands centered on 669 cm-1 for the O-H bonds and 1018 cm-1 for the Si-O bonds, as well as a degradation in the talc structure for prolonged milling times. BET results indicate an increase of specific surface area, which also confirms particle size reduction, reaching a maximum at 1 h, after which the particles agglomerate. Contact angle measurements show a decrease in the hydrophobicity of talc after milling. Although talc retains its hydrophobicity after short milling periods, prolonged grinding causes the mineral to have a more hydrophilic character.