Adsorption behaviour of PEO/PPO triblock copolymers on coals of different rank

摘要

Adsorption of PEO/PPO/PEO type blockcopolymers on surfaces of different rank coals was investigatedin this study. The interfacial behavior of block copolymers wasdetermined using surface tension measurements as a function ofboth surfactant type and concentration. With increase inconcentration, several distinct regions were observed in whichthe polymers displayed different degrees of association.Hydrophobicity of coals was measured using a modified contactangle measurement technique by which the relative distributionof hydrophobic and hydrophilic sites on the surface of coal wasestimated in addition to the mean hydrophobicity. The resultswere combined to propose a model which explains why blockcopolymers enhance flotation of coals.