Preparation And Characterization Of Electrospun PAN-based Carbon Composite Nanofibers With Porosity And Magnetism

Activated carbon fier(ACF) was an effective adsorbent with good chemical stability, good formability, low hydrodynamic resistance and high absorption efficiency. It was widely used in fields such as wastewater treatment, air purification, gas storage and catalyst. As activation temperature played a very important role in pore structure and pore size distribution of ACF, optimum activation temperature was studied to obtain ACF with high specific surface area. Meanwhile, to solve the recycling problem of ACF for wastewater treatment, some magnetic nanoparticles need to be introduced into the ACF, which would make practical application possible. In this paper, porous magnetic ACF with high specific surface area and micropore volume were prepared by electrospinning. Specific details go as follows:(1) Homogenous continous PAN nanofibers which taked PAN and DMF as raw materials were prepared by a improved electrospinning device. After activated by carbon dioxide(CO2), PAN-based activated carbon nanofibers were obtained. The effect of activation temperature on pore structure and pore size distribution of ACFs were emphatically studied. It was found that specific surface area(SBET),total Pore volume(Vtotal) and micropore volume(Vmi) increased with increasing activation temperature. When the temperature rised to950℃, SBET、Vtotal、Vmia、Vmit and VmiD reached up tol484.5m2/g、0.709cm3/g.0.680cm3/g、0.666cm3/g and0.659cm3/g. The methylene(MB) adsorption isotherm of ACF950conformed to both Langmuir equation and adsorptive capacity for MB onto ACF950was270mg/g at25±1℃.(2) Magnetic carbon composite nanofibres, with the mixed homogeneous solution consist of PAN, ferric acetylacetonate(AAI) and dimetbylformamide(DMF), were prepared by using electrospinning-calcination technology. Results showed that saturation magnetization(Ms) and remanent magnetization(Mr) increase with the increasing of the temperature. When carbonization temperature was900℃, MSt Mr and coercivity(Hc) were27.55emu/g,5.10emu/g and250Oe. Moreover, SRET and Vtotal were up to354.0m2/g and0.315mL/g, respectively. The carbon nanofibre diameter of sample CF900is about130-210nm. It can be used to prepare recoverable efficient adsorbent, catalyst carrier, microwave absorption materials, battery materials, etc.(3) The electrospinning-chemical activation method was applied to obtained magnetic porous carbon composite nanofibres from a solution containing PAN, AAI and DMF. Experimental evidence suggested that SBET,Vtotal, Vmi and Vmic. of magnetic carbon composite nanofibres increased significantly after adding KOH. When the concentration of KOH solution was1.0wt%, SBet,Vtotal, Vmia, Vmit and VmiD were up to1295.7m2/g,0.647cm3/g,0.562cm3/g,0.530cm3/g and0.541cm3/g. The ACF1.0, of which Ms, Mr and Hc were6.64emu/g,0.54emu/g and150Oe, was a good material for wastewater treatment and catalyst carrier.