Preparation Of Cu(Ⅱ)-imprinted Nanofibers And Their Selective Adsorption Performance

With the development of PCB industry,copperion pollution problemsbecome moreand more serious.Therefore,it is important todevelopa fast and efficient technology fortreatment of copperpolluted water,and achieve reuse or recycling of copper resources.The metal ion-imprinted polymer is a kind of adsorbent with high selectivity andadsorption capacity,whichis a hot topic in heavy metal pollution control.In this study,nanofibers were prepared by electrospinning.Subsequently, thenanofibers were crosslinked and the Cu(Ⅱ)-imprinted nanofibers were obtained afterCu2+template ions were elutedwith HCl.Their performanceswere investigated and themainly results were given as follows:(1)The mainly ingredients of Cu2+was in the form of complexes with L-Histidineinelectrospinning solutions at pH=4.5, when themolarity ratio of copper ion toL-Histidine was kept at1:2.2.(2) The diameter of PVA/Cu(Ⅱ)-L-histidine nanofibers was290±102nm,when theoptimized conditions of solution concentration13wt%, voltage26kV, working distance7cm, flowing rate0.4ml/h were applied.(3) Cu(Ⅱ)-imprinted nanofibers with diameter of480±91nm were harvestedthrough crosslinked with glutaraldehyde vapor for24h at room temperature andepichlorohydrin for3h, and elutedtemplate ions of coppersubsequently.(4) The maximum adsorption capacity of Cu(Ⅱ)-imprinted nanofibersfor Cu2+atinitial concentration of100mg/L was41.6mg/g at pH=6.(5) The adsorption dynamicsof Cu(Ⅱ)-imprinted nanofibers forCu2+obeyedpseudo-second-order model, and kinetic studies showed thatadsorption equilibrium timewas within40minuteand the equilibrium adsorption capacity was32.68mg/g wheninitial concentration of copper ion solutionwas100mg/L at pH4.5.(6) The adsorption capacity of Cu(Ⅱ)-imprinted nanofibers increased with theinitial concentration of copper ion solution,the adsorption was typical chemicaladsorption and the isothermal adsorption datas fitted well with Langmiur equation.Theadsorption capacity of Cu(Ⅱ)-imprinted nanofibers increased when temperature waselevated, which indicated that the adsorption process was endothermic.(7) In simulatedbinary metal ion solutions, the selectivityofCu(Ⅱ)-imprintednanofibers remained high.The selectivity coefficients of Cu(Ⅱ)-imprinted nanofibers for Cu2+respect to Pb2+,Ni2+and Zn2+were51.6,54.4and66.3,respectively.(8) The adsorption capacity of Cu(Ⅱ)-imprinted nanofibers for Cu2+was28.87mg/g afteradsorption/desorption for five times,which was88.3%of the firstadsorption capacity.This results implied that Cu(Ⅱ)-imprinted nanofibers have goodrecycling performance.