Preparation of boron nitride nanofibers/PVA composite foam for environmental remediation

Abstract

By combining of one-dimensional porous boron nitride nanofibers (BNNFs) with polyvinyl alcohol (PVA) via a freeze-drying method, a new type of BNNFs/PVA composite foam has been successfully obtained. The composite foam shows a honeycomb network structure containing a large number of pores. The BNNFs, with the characteristics of high aspect ratio, large pore volume, high specific surface area and good flexibility, act as a bridge connecting matrix to improve the flexibility of the composite foam. With the increasing of contents of BNNFs, the composite foam displays enhanced specific surface area. The addition of BNNFs also leads a tendency to change the foam from hydrophilic to hydrophobic. The BNNFs/PVA composite foams show excellent oil-water separation performance with absorption capacities for silicon oil and pump oil in the range of 1979∼6110 wt%. Moreover, the addition of BNNFs significantly improves the adsorption capacity of the composite foam for cationic dyes due to the hydrogen bonding and electrostatic interaction between BNNFs/PVA composite and cationic dyes. The high specific surface area of composite foam is also beneficial for the CO2 gas adsorption. The developed BNNFs/PVA composite foam has shown a great potential in the field of environmental remediation.