D3.1 – Report on 1st generation of advanced PVDF membranes for MD

In this Deliverable are presented the main results obtained in the first six months of project on the development (CNR) and characterization (UNICAL and CNR) of membranes prepared with green solvents and of specific coatings to enhance their performance in Membrane Distillation (MD). In particular, the main objectives were: 1. To develop a preparation procedure, using γ-Valerolactone (GVL) as a bio-based and greener solvent, that allowed to obtain poly(vinylidene fluoride) (PVDF) membranes with a pore size in the range from 0.1 μm to 0.8 μm; 2. To study and optimize the dope solution compositions and the casting conditions in order to obtain membranes with physical-chemical properties comparable to those commercially available from GVS Company; 3. To develop a coating procedure to enhance the hydrophobicity of the PVDF membrane prepared from CNR-ITM and commercially available from GVS Company. The strategy involved the surface functionalization of PVDF membrane by dip-coating deposition of a ceramic nanostructured hierarchical xerogel of nanoparticles obtained via sol-gel synthesis (Al2O3, SiO2) using different biomimetic approaches to significantly lower the surface energy down to the order of mN/m; 4. To carry out preliminary MD characterization tests (with deionised water as feed) on the PVDF membranes with a pore size of 0.2 μm, specifically: • PVDF membranes prepared by CNR-ITM • PVDF membranes commercially available from GVS Company • PVDF membranes (CNR-ITM) coated following the procedure developed at CNR-ISSMC • PVDF membranes (GVS) coated following the procedure developed at CNR-ISSMC