Synthesis of new fluorinated foaming particles

Abstract

This paper describes how to synthesise new hydrophobic foaming particles by grafting short fluorinated phosphonic acid (3 carbons) on commercial hydrophilic alumina particles. The short grafting fluorinated agent CF 3–CFH–CF 2–P(O)(OH) 2 preparation is detailed. The corresponding hydrophobic foaming particles are easily prepared by acidic–alkaline grafting using this molecule. “Bikerman foams” are easily generated by air sparging through an aqueous suspension of fluorinated alumina particles. The expansion ratio of the foam could be greater than 20. On a free drainage configuration, relatively dry foams were obtained with a high life time, more than 10 h. The mechanism of stabilisation proposed to describe the role of the particles is based on the attachment of the particles at the air–water interface.