Efficient fog harvesting through electrospun superhydrophobic polyacrylonitrile nanocomposite fiber mats

Abstract

To address the global water scarcity issue especially in arid and semi-arid regions, efficient water collecting surfaces with fast capturing and easy drainage are essential. This concern is drastically increasing and therefore scientists and engineers are challenged with urgently developing viable solutions for this global problem. Among many other options, nanoscale membranes seem to be quite attractive and very promising options to solve the global water problem due to their low energy cost and simple operational processes to produce clean and fresh water. In this work, polyacrylonitrile (PAN) and poly (methyl methacrylate) (PMMA) with various proportions of titanium dioxide (TiO2) nanoparticles and aluminum (Al) microparticles were electrospun into superhydrophobic nanocomposite fibers using electrospinning technique followed by stabilization and carbonization steps to remove all non-carbonaceous materials from the fibers and used for harvesting fog from the atmosphere. The fiber morphology, surface hydrophobicity, and fog harvesting capacity of the nanocomposite fibers were investigated. Test results reveal that the carbonized nanocomposite fibers mats exhibit superhydrophobic characteristics with a water contact angle of 155° and an efficient fog harvesting capacity of 621 mg/cm2/hr. Besides, water can be efficiently collected from the atmospheric fog and filtered using nano-membranes without using any large infrastructure. The produced water can be used for drinking, agriculture, gardening, medical, industrial, and other purposes.