Novel nanofibrous scaffolds for water filtration with bacteria and virus removal capability.

We demonstrate a new class of composite fibrous membranes, consisting of an ultra-fine cellulose nanofibrous network infused into an electrospun polyacrylonitrile (PAN) nanofibrous scaffold on a melt-blown polyethylene terephthalate (PET) non-woven substrate for water purification. Depending on the infusion process and the ultra-fine cellulose nanofibers (UFCNs) used [e.g. modified ultra-fine cellulose nanofibers (m-UFCNs) or microcrystalline cellulose nanofibers (MCCNs)], different nanostructured scaffolds were formed as seen by electron microscopy. Membranes with UFCNs consist of an interwoven two-dimensional ultra-fine nanofibrous network that is deeply entangled with the electrospun scaffold and organized in a quasi-three-dimensional fashion, while those with MCCNs tend to locally wrap around the electrospun scaffolding nanofibers without forming a major network. Filtration tests illustrated that both membranes, while maintaining high permeation flux, exhibited excellent retention capabilities for simultaneous sieving for bacteria and adsorption for viruses.