Oriented shish-kebab like ultra-high molecular weight polyethylene membrane for direct contact membrane distillation

The special bioinspired structure will help membranes to improve the antifouling properties during the membrane distillation (MD) process. Here, a new MD utilized membrane with oriented shish-kebab structure was prepared by stirring the ultra-high molecular weight polyethylene (UHMWPE)/decalin solution to induce the shish-kebab crystals to grow on a polyester mesh along the flow field, and then coated with fluororesin to decrease the surface energy. The multi-stage extraction drying technology was adopted to reduce the membrane shrinkage in the dry process and make the shish-kebab membranes have high porosity (77.5%). More interesting, when the water flows along the shish direction, just like the fish gill works, the membrane has better resistance to NaCl, CaCO3 scaling, due to the nanoscale structure can intensify the interfacial nanoscale turbulent flow and hinder the crystal deposition. Specifically, the membrane has a high-water recovery of 92.5% and a low conductivity increase (from 2.76 to 8.33 μS/cm in 70 h) in the long-term MD process.