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Membrane crystallization is today recognized as an innovative and efficient method for enhancing crystallization of biomolecules, allowing the production of crystals with controlled shape, size distribution, and polymorphism. Membranes are used both to promote an efficient mass transfer of solvent for a better control of the supersaturation, and to activate heterogeneous nucleation for a reduced induction time. The development of membranes having ordered structures and tailored surface properties is, therefore, a key issue in order to fully exploit the potential of membrane crystallization. In this work, theoretical and experimental correlations between the physico-chemical properties of the membranes, kinetics of nucleation and the characteristics of the final product are presented.

One of the membrane-based technique for harvesting salinity gradient energy is Reverse Electrodialysis (RED). Most of the studies in literature are based on utilizing river and seawater by mimicking them with NaCl solutions. However, real solutions contain many different ions; this study deals with the impact of Mg2+ ion onpower density (Pd). Investigations have been carried out using six solutions of NaCl and MgCl2 prepared in varying compositions from 0 % to 100 %. Increasing Mg2+ concentration resulted in a remarkable decrease of Pd and open circuit voltage (OCV), and in a significant increase in stack resistance Rstack. Electrochemicalimpedance test (EIS) and ion chromatography analysis helped to clarify reasons for loss of power. In particular, it was found out that dominant negative contribution is due to increasing Cation Exchange Membrane (CEM) resistance in the presence of Mg2+.