The use of emulsions as a means of studying the kinetics of homogeneous nucleation has been well known for a number of years. In this contribution, however, attention is given to the possible use of emulsions in novel process technology, on the one hand as a means of directing the size and morphology of particulate materials and on the other as the basis for melt purification. m-Chloronitrobenzene serves as a model compound in this work, although the central concepts are valid for any low melting molecular material. Particular attention has been paid to the choice and mode of action of the emulsifier since it is this which ultimately controls the outcome of the crystallization process.