Functional Modification Of Polyacrylonitile Nanofiber Mats And ITS Application

Water pollution and freshwater shortage are critical global problem facing human. These critical challenges are driving global researchers to develop new materials. Nano-materials are now providing new solutions. Nanofibers with large surface area enable them high functionalization ability, thus are attractive for many applications. Among the many methods to generate nanofibers, electrospinning is an efficient and low-cost technique to provide nanofibers with interconnected porous structure and uniform morphology.1. Surface molecular imprinting inLayer-by-Layer (SMI-LbL) film is known as a facile and effectivestrategy to build imprinting sites inpolymers. We accomplished the formation of SMI-LbL film on electrospunpolyacrylonitrile(PAN) nanofibers. The obtained nanofiber mat maintained the nanofibrous structure and showed rapid absorption and extraction of template molecules of meso-tetra(4-carboxyphenyl)-porphine (Por). The binding capacity of Porreached2.1 mg·g-1 when 3.5 bilayers were deposited on the nanofibers. After six cycles of extraction and reabsorption, the binding capacity ofPor remainedat 83%. Moreover, the absorption results of the targeted templated molecule of Por and the control molecule of Fast Green, which had a very similar chemical structure and chargestatus to Por, indicated that the imprinted film hadbetter affinity for templated Por.2. Graphene oxide (GO) sheets are known as one-atom thick sheets with impermeability, excellent mechanical property and high surface-to-volume ratio. GO films fabricated by the stack of GO sheets recently have been tried for filtration applications, revealing promising properties. In this work, GO-PAN composite membrane was fabricated by vacuum-assisted filtration of GO solution on PAN nanofiber mat. These novel GO-PAN nanofiber composite membranes show excellent separation performance for nanofiltration applications. Under our testing conditions, these novel composite nanofiltration membranes exhibit a high pure water flux up to 8.2 Lm-2 h-1 bar-1 with high rejection for Congo red (about 99.9%).