Optimization of the transport of aminic substrates

A series of aminic substrates were transported and separated by means of a chloroformic liquid membrane. Several system parameters (source phase pH, receiving phase pH, carrier concentration, substrate concentration, stirring rate, transport duration) were investigated in order to determine the best experimental conditions that allow a proper separation of aliphatic and aromatic amines from aqueous mixtures. As the substrate started to be transferred against its concentration gradient, the part played by the carrier became more important. The results were analyzed assuming that the global transport experiment consisted of a series of extraction equilibria taking place simultaneously at the two water–membrane interfaces, and considering that the rate determining process was the diffusion of the neutral substrate, and its association with the carrier through the organic membrane. Aniline could be successfully separated from dimethylaniline, and di-n-butylamine, and cyclohexylamine from morpholine, fact that encouraged the working out of the environmental aspects of our project.