Preparation And Study Of Functionalized Polyacrylonitrile Nanofibers

As a new fabrication method for nanofibers and microfibers,solution blowing has recently attracted significant attention.It combines the superiority of electro spinning in fabricating fibers with diameters from hundreds of nanometers up to a few micrometers and the capability of melt blowing in preparing microfibers on a commercial production scale.Solution blowing has the superiorities of simple process,low energy consumption,high production efficiency.In this work,we prepared functional composite fiber by solution blowing.And the morphology,properties and performances of the fibers were also studied.The details are as follows:1.Polyaniline（PANI）/Polyacrylonitrile（PAN）core-shell nanofiber mat.We produced PAN nanofiber mat by solution blowing.By altering the processing parameters,bead-free and uniform PAN nanofibers could be obtained.And composite nanofibers mat containing PAN as core and PANI as sheath had been successfully prepared via in situ polymerization.The orthogonal experiments were designed to determine the optimal reaction conditions for the conductivity of PANI/PANcomposites and the conductivity arrived at 8.22×10-3 S/cm.And its hexavalent chromium（Cr（VI））removal potential was investigated,the PANI/PAN composite nanofiber mats presented a superior Cr（VI）adsorption performance.Moreover,the factors affecting the performance of Cr（VI）removal from the aqueous solutions were investigated systematically.The experimental data were fitted to various kinetic models and isothermal adsorption,and the thermodynamic parameters of adsorption process were calculated as well.The PANI/PAN adsorbents were also proven to have good recycling capability,and the mechanism of adsorption and regeneration was investigated in detail.2.Cu_xS/PAN composite fiber:Firstly,we have obtained PAN nanofiber mat by solution blowing.Secondly,the conductive PAN fiber mat were prepared by relatively simple solution growth method using copper sulfate.The Cu_xS/PAN composte fiber mat had good electrical conductivity.The effects of copper sulfide solution and sodium thiosulfate solution concentrations and dipping temperature and time on the conductivity of PAN fibers were studied.SEM micrographs showed a homogeneous distribution of copper sulfide.From combined XRD analysis and XPS analysis we conclude that CuS and Cu₉S₅ were the main phase whin the resultant Cu_xS film.The best EMI SE of the composites was about 27～31 dB.