Quantification and controls of oriented processes through affinity polymer membranes for the extraction and purification of lactic acid compound

Currently, membrane technologies represent an essential research field, particularly affinity polymer membranes, which are widely used for treatment processes in green and sustainable chemistry. In this study, two affinity polymer membranes were developed, containing cholic acid (CA) and methyl cholate (MC), as extractive agents. Several physico-chemical techniques have been adopted to specify the characteristics of developed membranes. These membranes were adopted to perform experiments related to facilitated extraction processes of lactic acid (LA). Experimental kinetic studies allow determining, permeability (P), and initial flux (J(0)) to quantify membrane' performances. Similarly, association constant (K-ass), and diffusion apparent coefficient (D*), relating to the diffusion of LA substrate through the membrane phase were determined. Thermodynamic and activation parameters (enthalpy delta H-th, energy E-a, enthalpy delta H-&NOTEQUexpressionL;, and entropy delta S-&NOTEQUexpressionL;) were calculated. All parameters allow to elucidate the movement nature of the substrate through the membrane phase and to specify the kinetic or energetic aspect that controls the process mechanism. Results indicate that under same experimental conditions, SLM is more permeable for LA than PIM membrane, due to the different mechanisms across the two membranes. However, high stability of PIM membrane indicates that it may be a useful alternative to the instability of SLM membrane.