화학공학소재연구정보센터
Journal of Hazardous Materials, Vol.334, 160-167, 2017
Enhancing the antimony sorption properties of nano titania-chitosan beads using epichlorohydrin as the crosslinker
Antimony is classified as a pollutant of priority importance by USEPA. We have earlier reported the synthesis of nano-titania impregnated epichlorohydrin crosslinked chitosan (TA-Cts-Epi) beads, in a format suitable for large scale applications with high sorption capacity for antimony. To understand the sorption mechanism, and to fine tune the bead composition, the effect of crosslinking density on the swelling and sorption properties of the beads was investigated in detail. Epichlorohydrin effected significant changes in physical and sorption properties of the beads. The antimony sorption capacity of the TA-Cts-Epi beads prepared by crosslinking 03 g non-crosslinked titania-chitosan beads (TA-Cts-NCL) with 6.4 mmol epichlorohydrin was 493 mu mol/g, while those crosslinked with 0.64 mmol showed a capacity of 133 mu mol/g. Whereas, TA-Cts-NCL beads showed a capacity of 75 mu mol/g. The increase in uptake capacity with increase in crosslinking demonstrated the active involvement of the epichlorohydrin moieties in antimony binding leading to enhanced sorption. Apart from altering the stability, swelling behaviour and sorption kinetics of the beads, crosslinking significantly increased the uptake of the anionic species via electrostatic interactions. Epichlorohydrin crosslinked chitosan beads prepared without TiO2 also showed similar behaviour. The results demonstrated the involvement of chitosan, TiO2 and epichlorohydrin in sorption. (C) 2017 Elsevier B.V. All rights reserved.