EFFECT OF MATERIAL PROPERTIES ON THE DRAINAGE OF SYMMETRICAL, PLANE-PARALLEL, MOBILE FOAM FILMS

Drainage of a mobile, symmetric, plane parallel thin liquid film betwe en two gas bubbles is studied, An analytical solution for the hate of thinning of such a liquid film with an insoluble surfactant and having both film elasticity and surface viscosity is presented for the first time. Analysis is extended to the more general case of a soluble surf actant and compared with previous analyses. Surfactant material parame ters affecting the rate of thinning are identified and grouped into a single dimensionless parameter which describes the transition from a m obile to an immobile firm. Significant deviation from the Reynolds vel ocity is found when this dimensionless parameter is small. (C) 1996 Ac ademic Press, Inc.