ON THE ATTACHMENT OF HYDROPHOBIC PARTICLES TO A BUBBLE ON THEIR COLLISION

The attachment of hydrophobic particles to bubbles on collision has been investigated theoretically. The role of hydrophobicity is revealed in the slippage of liquid over a solid surface and in increasing critical thickness of an interlayer on reaching the latter, its rupture occurs with the formation of a contact angle. An expression has been derived for the velocity at which a particle approaches a bubble. On the basis of the analysis of that expression, it has been demonstrated that hydrophobicity is a relative concept from the point of view of the approach dynamics. Criteria of attachment have been formulated, and the induction time has been analysed for particles with various degrees of hydrophobicity.