A few-layer graphene for advanced composite PVDF membranes dedicated to water desalination: a comparative study

Membrane distillation is envisaged to be a promising best practice to recover freshwater from seawater withthe prospect of building low energy-consuming devices powered by natural and renewable energy sourcesin remote and less accessible areas. Moreover, there is an additional benefit of integrating this greentechnology with other well-established operations dedicated to desalination. Today, the development ofmembrane distillation depends on the productivity-efficiency ratio on a large scale. Despite hydrophobiccommercial membranes being widely used, no membrane with suitable morphological and chemicalfeature is readily available in the market. Thus, there is a real need to identify best practices fordeveloping new efficient membranes for more productive and eco-sustainable membrane distillationdevices. Here, we propose engineered few-layer graphene membranes, showing enhancedtrans-membranefluxes and total barrier action against NaCl ions. The obtained performances are linked withfilling polymeric membranes with few-layer graphene of 490 nm in lateral size, produced by the wet-jetmilling technology. The experimental evidence, together with comparative analyses, confirmed that theuse of more largely sized few-layer graphene leads to superior productivity related efficiency trade-offfor the membrane distillation process. Herein, it was demonstrated that the quality of exfoliation isa crucial factor for addressing the few-layer graphene supporting the separation capability of the hostmembranes designed for water desalination