3. Model Development and Effects of the Various Model Parameters

The step-by-step process involved in developing the membrane performance prediction model is presented here. In the developed model, the membrane performance measured as the concentration of the solute in the permeate is related to the Young’s modulus of the membrane material while under permeation, solvent density, Poisson ratio (ν), extent of membrane constraint, swelling to compaction ratio, solvent and solute solubility parameter difference; solute partitioning between the solvent and membrane; solvent and membrane polymer density ratio, as well as the solvent and membrane molar volumes. This chapter presents the sensitivity of all these parameters on membrane performance. Emphasis is placed on simultaneous membrane swelling and compaction which appears to be a major issue and presents some clues to understand the separation performances of polymeric membranes applied for organic system separation. The model shows membrane constraint and densification as results of compaction controlled transport of solute molecules across polymeric membranes. Moreover, the model is capable of determining the effects of the type solvents, i.e., polar aprotic, polar protic and non-polar on separation performance. Finally, the model developed led to defining of a new dimensionless number characteristics of the separation systems. UTDR technology is employed to extract real-time useful information about the model.