Electro spun Carbon Nano fiber Membranes for Filtration of Nanoparticles from Water

Nowadays, hundreds of consumer products contain metal and metal oxide nanoparticles (NP); this increases the probability of such particles to be released to natural waters generating a potential risk to human health and the environment. This paper presents the development of efficient carboneous nano fibrous membranes for NP filtration from aqueous solutions. Free-standing carbon nano fiber (CNF) mats with different fiber size distribution ranging from 126 to 554 nm in diameter were produced by electro spinning of polyacrylonitrile (PAN) precursor solution followed by thermal treatment. Moreover, tetraethoxyorthosilicate was added to provide flexibility and increase the specific surface area of the CNF. The resulting membranes are bendable and mechanically strong enough to withstand filtration under pressure or vacuum. The experimental results of filtration revealed that the fabricated membranes could efficiently reject nanoparticles of different types (Au, Ag, and TiO₂) and size (from 10 to 100 nm in diameter) from aqueous solutions. It is worth mentioning that the removal of Ag NP with diameters as small as 10 nm was close to 100% with an extremely high flux of 47620 L m^-2 h^-1 bar^-1.