Membrane distillation (MD) has been identified as a promising desalination technology capable of utilizing low-grade heat. As a thermal separation process, MD employs hydrophobic microporous membranes as the medium for water vapor transport.  One of the major challenges facing MD is wetting by low surface tension contaminants, which is of particular concern for application of MD in desalinating municipal wastewater or produced water from oil and shale gas productions. To overcome this problem, we developed an omniphobic membrane by modifying the surface morphology and chemistry of a hydrophilic microporous membrane. The resulting surface nanostructure enables the membrane to effectively repel both water and oil. We compared the performance of the omniphobic membrane and a conventional hydrophobic membrane (e.g. PTFE) in MD operation in the presence of surfactants. Our results show that the hydrophobic membrane fails as an MD membrane due to wetting, whereas the omniphobic membrane can sustain robust MD operation even in the presence of surfactants.

Novel omniphobic microporous membrane for direct contact membrane distillation

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.