Canberra ACT 0200

Phase change materials (PCM) are often used as heat storage media, providing heat buffering to thermal systems. Conventional PCMs have a number of problems, some of which are being addressed by researchers. Two of the more serious problems are the poor thermal conductivity of most PCM materials and that the PCM must fixed in place by its physical size and solid nature. The authors propose a microencapsulated PCM that is suspended in a solution, thus creating a fluid of very high specific heat capacity over a narrow temperature range. Microencapsulation has previously been applied to solid materials such as wallboards and in the food and pharmaceutical industries, but seldom as heat transfer fluids Using this technique, not only is a high surface area to volume ratio possible, but the heat store is effectively mobilised. Furthermore, the stored heat creates essentially isothermal conditions where they are required. This paper discusses early research into the manufacture of such material using the complex coacervation technique and some of the resultant PCM colloidal solution properties. 1