Farrell, Sinéad T. and Breslin, Carmel B. (2004) Reduction of Cr(VI) at a polyaniline film: Influence of film thickness and oxidation state. Environmental Science and Technology, 38 (17). pp. 4671-4676. ISSN 0013-936X

Preview

Download (129kB) | Preview

Abstract

Hexavalent chromium [Cr(VI)] is highly toxic, carcinogenic, and mutagenic to living organisms. In this paper, the reduction of Cr(VI) to the much less toxic trivalent state [Cr(III)] was studied at polyaniline films grown to different thickness. Much higher rates of Cr(VI) reduction were observed for the “thick” polyaniline films. This was explained in terms of the morphology of the polymer and the higher surface area of polymer in contact with the Cr(VI) solution. For “thin” polyaniline films, the Cr(VI) reduction reaction was found to obey pseudo-first-order kinetics for the duration of exposure. However, in the case of thick polyaniline layers, the Cr(VI) reduction reaction followed a two-stage process, with each stage obeying pseudo-first-order kinetics. This was explained in terms of oxidation of the polymer from the leucoemeraldine to the emeraldine state and then further oxidation of the polymer from the emeraldine to the pernigraniline state. Much higher rates of Cr(VI) reduction were observed on oxidation of the polymer from the leucoemeraldine to the emeraldine state.

Item Type:	Article
Keywords:	Cr(VI); polyaniline film; film thickness; oxidation state; Hexavalent chromium [Cr(VI)]; Toxicity;
Academic Unit:	Faculty of Science and Engineering > Chemistry
Item ID:	7930
Identification Number:	https://doi.org/10.1021/es0498585
Depositing User:	Dr. Carmel Breslin
Date Deposited:	15 Feb 2017 16:37
Journal or Publication Title:	Environmental Science and Technology
Publisher:	American Chemical Society
Refereed:	Yes
Funders:	Daniel O’Connell Scholarship, Enterprise Ireland (EI)
URI:	http://pubs.acs.org
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

Repository Staff Only(login required)

Item control page

Downloads

Origin of downloads