Polyaniline nanofibers as highly effective re-usable adsorbent for removal of reactive black 5 from aqueous solutions

Madhumita Bhaumik; Rob I McCrindle; Arjun Maity; Shilpi Agarwal; Vinod Kumar Gupta

doi:10.1016/j.jcis.2015.12.056

Polyaniline nanofibers as highly effective re-usable adsorbent for removal of reactive black 5 from aqueous solutions

J Colloid Interface Sci. 2016 Mar 15:466:442-51. doi: 10.1016/j.jcis.2015.12.056. Epub 2015 Dec 30.

Authors

Madhumita Bhaumik¹, Rob I McCrindle², Arjun Maity³, Shilpi Agarwal¹, Vinod Kumar Gupta⁴

Affiliations

¹ Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa.
² Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria, South Africa.
³ Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa; DST/CSIR National Centre for Nanostructured Materials, Materials Science and Manufacturing, Council for Scientific and Industrial Research (CSIR), Pretoria, South Africa. Electronic address: amaity@csir.co.za.
⁴ Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa; Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India. Electronic address: vinodfcy@gmail.com.

PMID: 26771507
DOI: 10.1016/j.jcis.2015.12.056

Abstract

Polyaniline nanofibers (PANI NFs) with 50-80 nm in diameter were successfully prepared at room temperature (22 °C) using ferric chloride (FeCl3) as an oxidant via a simple rapid mixing polymerization method. The prepared PANI NFs were characterized by FE-SEM, HR-TEM, BET, ATR-FTIR and by Zeta potential measurement method. The adsorption of azo dye Reactive Black 5 (RB5) onto PANI NFs from aqueous solutions was investigated. Adsorption studies were carried out at different initial dye concentrations, initial solution pH and adsorbent doses. The kinetic data fitted well with the pseudo-second-order model while the equilibrium data were satisfactorily described by the Langmuir isotherm model. The Langmuir maximum adsorption capacity of RB5 at pH 6.0 was found to be 312.5, 389.1 and 434.7 mg/g at 25 °C, 35 °C and 45 °C, respectively. Thermodynamic parameters including the Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) changes indicated that the adsorption of RB5 onto PANI NFs was feasible, spontaneous, and endothermic. Moreover, desorption experiments revealed that the PANI NFs can be reused effectively for five consecutive adsorption-desorption cycles without any loss of its original capacity.

Keywords: Adsorption; Isotherm; Kinetics; Nanofibers; Polyaniline; Reactive black 5.

Publication types

Research Support, Non-U.S. Gov't