Engineering of responsive polymer based nano-reactors for facile mass transport and enhanced catalytic degradation of 4-nitrophenol

Robina Begum; Zahoor H Farooqi; Zonarah Butt; Qingshi Wu; Weitai Wu; Ahmad Irfan

doi:10.1016/j.jes.2017.12.003

Engineering of responsive polymer based nano-reactors for facile mass transport and enhanced catalytic degradation of 4-nitrophenol

J Environ Sci (China). 2018 Oct:72:43-52. doi: 10.1016/j.jes.2017.12.003. Epub 2017 Dec 14.

Authors

Robina Begum¹, Zahoor H Farooqi², Zonarah Butt³, Qingshi Wu⁴, Weitai Wu⁴, Ahmad Irfan⁵

Affiliations

¹ Centre for Undergraduate studies, University of the Punjab, New Campus, Lahore 54590, Pakistan.
² Institute of Chemistry, University of the Punjab, New Campus, Lahore 54590, Pakistan. Electronic address: zahoor.chem@pu.edu.pk.
³ Institute of Chemistry, University of the Punjab, New Campus, Lahore 54590, Pakistan.
⁴ State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
⁵ Department of Chemistry, Faculty of Science, King Khalid University, Abha 61413, Saudi Arabia; Research Center for Advanced Materials Science, King Khalid University, Abha 61413, Saudi Arabia.

PMID: 30244750
DOI: 10.1016/j.jes.2017.12.003

Abstract

Silver nanoparticles with average diameter of 10±3nm were synthesized within the sieves of poly(N-isopropylacrylamide-2-hydroxyethylmethacrylate-acrylic acid) (p(NIPAAm-HEMA-AAc)) polymer microgels. Free radial emulsion polymerization was employed for synthesis of p(NIPAAm-HEMA-AAc) polymer microgels. Silver nanoparticles were introduced within the microgels sphere by in situ reduction method. Microgels and hybrid microgels were characterized by Fourier transform infrared spectroscopy, ultra violet-visible spectroscopy, transmission electron microscopy and dynamic light scattering measurements. Catalytic activity of Ag-p(NIPAAm-HEMA-AAc) hybrid microgels was studied using catalytic reduction of 4-nitrophenol (4-NP) as a model reaction in aqueous media. The influence of sodium borohydride (NaBH₄) concentration, catalyst dose and 4-NP concentration on catalytic reduction of 4-NP was investigated. A linear relationship was found between catalyst dose and apparent rate constant (k_app). The mechanism of catalysis by hybrid microgels was explored for further development in this area. The deep analysis of catalytic process reveals that the unique combination of NIPAAm, HEMA and AAc does not only stabilize silver nanoparticles in polymer network but it also enhances the mass transport of hydrophilic substrate like 4-NP from outside to inside the polymer network.

Keywords: Catalytic degradation; Hybrid microgels; Metal nanoparticles; Polymer microgels.

MeSH terms

Metal Nanoparticles / chemistry*
Models, Chemical*
Nitrophenols / chemistry*
Silver / chemistry*

Substances

Nitrophenols
Silver
4-nitrophenol