Polyacrylonitrile/Aminated Polymeric Nanosphere Nanofibers as Efficient Adsorbents for Cr(VI) Removal

In this work, polyacrylonitrile/aminated polymeric nanosphere (PAN/APN) nanofibers were prepared by electrospinning of monodispersed aminated polymeric nanospheres (APNs) for removal of Cr(VI) from aqueous solution. Characterization results showed that obtained PAN/APNs possessed nitrogen functionalization. Furthermore, the adsorption application results indicated that PAN/APN nanofibers exhibited a high adsorption capacity of 556 mg/g at 298 K for Cr(VI) removal. The kinetic data showed that the adsorption process fits the pseudo-second order. A thermodynamic study revealed that the adsorption of Cr(VI) was spontaneous and endothermic. The coexisting ions Na+, Ca2+, K+, Cl-, NO3- and PO43- had little influence on Cr(VI) adsorption, while SO42- in solution dramatically decreased the removal performance. In the investigation of the removal mechanism, relative results indicated that the adsorption behavior possibly involved electrostatic adsorption, redox reaction and chelation. PAN/APN nanofibers can detoxify Cr(VI) to Cr(III) and subsequently chelate Cr(III) on its surface. The unique structure and nitrogen functionalization of PAN/APN nanofibers make them novel and prospective candidates in heavy metal removal.

Automated summary

Polyacrylonitrile/aminated polymeric nanosphere (PAN/APN) nanofibers were successfully prepared by electrospinning for the removal of Cr(VI) from aqueous solution. The obtained PAN/APNs showed nitrogen functionalization and exhibited a high adsorption capacity. The adsorption process followed pseudo-second order kinetics and was found to be spontaneous and endothermic. Coexisting ions had little influence on Cr(VI) adsorption, except for SO42-, which significantly decreased the removal performance. The adsorption mechanism possibly involved electrostatic adsorption, redox reaction, and chelation.