Study On Nanofiber Based On Poly (Ether Amine) And Its Application For Selective Adsorption And Molecular Filtration Of Dyes

With the development of industry, environment pollution is becomingworse and worse. More polluted water and gas is released, such asheavymetal ion, dyes and car exhaust, which has become one of threats to people’slife. Therefore, the treatment of waste water and gas is important. Asnanofiber has lots of advantage such as the high specific surface area, porousstructure and good adsorption capacity and easy to be recycled, it is moreeffective and beneficial to solve the pollution problem in environment.Membrane filtration is often used in separation and purification. It couldreduce energy-cost brought by separation of distillation. As the promotion inseparation techniques, molecular filtration is developed. That is to say, itallows separation of organic mixtures down to a molecular level. Themembrane filtration could occur at molecular level. It could separate twomolecules with similar size. So through it, not only the purification for waterand gas could be achieved, but also the separated organic molecule could berecycled and reused. Molecular filtration depends mainly on size-exclusion, the interaction between host and guest, such as electrostatic interaction,hydrogen bond. There are two important points for molecular filtration: highselectivity and high flux.Among the previous works in our group, we find poly(etheramine)(PEA) shows selective adsorption to different dyes. Based on thatstudy, we prepared PEA nanofiber through electrospining. Since exist ofcoumarin in PEA structure, the nanofiber could be cross-linked and thus itpossesses good solvent resistance. In addition, another PEA with differentcharge was designed to study the effect of electrostatic interaction to dyeadsorption. We find PEA nanofiber showed significant selectivity to dyesthrough the research on adsorption kinetics and maximum adsorptioncapacity. Combining the selectivity and solvent resistance performance ofPEA nanofiber, the dynamic adsorption behavior through filtration wasresearched. The selectivity was also showed to different dyes. And all theexperiments data suggests electrostatic interaction has no effect for itsselective adsorption. Then we used PEA nanofiber to separate dye mixturethrough molecular filtration. Two kinds of dyes could be successfullyseparated. And through washing by NaOH aqueous solution, the dyesadsorbed onto nanofiber could be desorbed. So the PEA nanofiber could beregenerated and reused. After ten separation-desorption runs, the separation efficiency could maintain the same with the first time, about95%and themorphology of PEA nanofiber nearly has no changes.