Preparation Of Nanomaterial Composite Using Electrospinning And Its Applications

Mercury pollution is a serious environmental problem which attracts a lot of global attentions. Trace mercury in atmosphere can settle down into soil or surface water. Mercury in water can be sequentially transformed into organic mercury which has been regarded as a particular toxin. Mercury pollution can pose risks to the health of human body for its high toxicity and bioaccumulation ability. Therefore, it is urgent to develop effective techniques for the removal and capture of trace mercury in water and atmosphere. Among the reported techniques for mercury removal, the adsorption method is the most popular and effective one. However, most of the commercial absorbents are not very suitable and effective for mercury removal because of its limited adsorption capacity, low specificity and non-recycling property. Therefore, it is very important and significant to develop new methods and materials which can remove mercury in water effectively with high capacity and regeneration ability.In this study, a series of silver nanomaterial composites were prepared and used for mercury removal. The main work contains several parts as below:(1) A Ag-PVA nanofiber composite membrane was synthesized by electrospinning and uitilized for mercury removal in water. SEM, XRD, FRIR and XPS were employed to characterize the prepared materials. The mercury adsorption process using this membrane was systematically studied. The effects of parameters including AgNO3 content,temperature, initial mercury concentration, pH, ions were investigated. Furthermore,its antibiotic ability was also tested. The results showed that the composite had good mercury adsorption capacity(229mg/g) and had good antibiotic ability.(2) The experiment was conducted to investigate the mercury removal ability of the composite as a filtration membrane. The influences of some parameters including AgNO3 content, initial mercury concentration, pH, ions were investigated.(3) A silver nanoparticles/carbon nanofiber composite(AgNPs/CNFs) was prepared by electrospinning and high-temperature calcination. AAgNO3/PVA(Poly Vinyl Alcohol)mixture solution was used as spinning precursor and silver ions were directly reduced into elemental silver nanoparticles during the process of electrospinning. The morphology of the as-prepared carbon nanofibers was characterized by SEM, and the silver nanoparticles loaded on the surface were confirmed by EDS. The capacity for elemental mercury removal was evaluated at 27 mg/g with excellent performance.The prepared composite can be regenerated by thermal treatment and reused for several cycles without obvious loss of adsorption capacity. The catalyst property ofthis nanocomposite was also studied by the degradation of 4-nitrophenol as a model.The results demonstrated that the nanofiber composite had good catalytic property.