“…The subscripts P , F and FM refer to the permeate side, the feed side and the feed side membrane-liquid interface, respective. The membranes used in this study consist of a rubbery separation layer cast on an ultrafiltration support, and belong therefore to the class of membranes characterised by a solution-diffusion transport mechanism, according to Marchetti and Livingston [25]. In order to account for mass transfer limitations and thermodynamic non-ideality of the solutions, Eqs.…”