THERMODYNAMIC STABILITY IN DISPERSE SYSTEMS

The stability or otherwise of disperse systems is determined in part b y the constraints to which they are subject. In particular, systems co nstrained to constant overall composition (closed systems) may differ in their stability from those in which one or more components can ente r or leave the system (open systems). This general consideration is il lustrated by several examples: the stability of volatile liquid drople ts in a vapour, of such droplets containing an involatile solute, emul sions, and the precipitation of crystals or colloidal particles. Anoth er example considered is that of adsorption of a vapour by a solid whe n the ratio of the amount of vapour component to solid adsorbent decre ases, and the corresponding case of adsorption from solution. The exte nt to which the stability depends on kinetic factors is also examined. (C) 1998 Elsevier Science B.V. All rights reserved.