Construction of intrinsic superhydrophobic ultra-high molecular weight polyethylene composite membrane for DCMD

A superhydrophobic membrane could effectively prevent the feed solution from wetting the membrane surface in membrane distillation (MD). The majority of reported superhydrophobic membranes utilized in MD were modified by hydrophobic agents (e.g. fluorosilicone), which pose potential risks to potable water production if they leach or lose coating materials. Here, intrinsic superhydrophobic ultra-high molecular weight polyethylene (UHMWPE) composite membranes were prepared by vacuum filter UHMWPE microgels onto a cheap commercial non-woven, and UHMWPE microgels were prepared by thermally induced phase separation. The prepared membranes have a "particle-like" structure, which makes the membrane have a high water contact angle (154.6°) and low sliding angle (2.5°). In addition, the membranes have a high water recovery of 93.6%, while the conductivity was just increased from 2.3 to 5.7 μS/cm in 83.0 h. Moreover, the membranes also have a high separation efficiency (99.9%) for treating anionic dyeing wastewater in the long-term experiment (50 h).