Preparation of Hierarchically Structured AOPAN@Mg(OH)2 Composite Nanofibrous Membrane and Cr(VI)-removal Capacity

The hierarchial aminated polyacrylonitrile(AOPAN)@ Mg(OH)(2) composite nanofibrous membrane was obtained by electrospinning technique and surface modification with hydroxylamine chloride prior to hydro-thermal method. The composite nanofibrous membranes were characterized by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), X-ray diffraction(XRD) and transmission electron microscope(TEM) to confirm the formation of Mg(OH)(2) nanoparticles on the AOPAN nanofibers. The results revealed that 40 degrees C/7 h was the best hydrothermal condition and Mg(OH)(2) nanoparticles were effectively load. ed on the surface of AOPAN nanofibrous membrane. The adsorption process showed pH dependence and the maximum Cr(VI) adsorption occurred at pH = 2. The Langmuir adsorption model described well the experimental adsorption data and estimated a maximum loading capacity of 123.5 mg/g. This is mainly due to the protonation of -NH2 groups and Mg(OH)(2) nanoparticles under the acid condition, which is benefit for adsorbing HCrO4-. The kinetics studies indicated that the adsorption equilibrium was attained after 5 h and the experimental data followed the pseudo. second order model. Meanwhile, the AOPAN@ Mg(OH)(2) composite nanofibrous membrane can be easily separated from liquid solutions and shows excellent cyclic utilization per. formance. The composite membrane maintained over 50% removal rate after rinsing with dilute NaOH solution by four cycles. Therefore, the AOPAN@ Mg(OH)(2) composite nanofibrous membrane could be a good candi. date for removing Cr(VI) from wastewater, and the study provides a simple and effective route for the develop. ment of new environmental remediation nanomaterials.