Isolation and characterization of cellulose-based nanofibers for nanoparticleextraction from an aqueous environment

Abstract

The increased use of nanoparticles in various commercial products enhances the contamination of nanomaterials in the environment which may cause serious health concern in the near future. To address this problem, new methods need to be developed for removal of nanomaterials from the environment. In this report, we explored the removal of nanoparticles from water using cellulosic nanofibers extracted from a renewable source such as sugarcane bagasse. The nanofibers were coated with chitosan to introduce additional functional groups on the surface. The designed cellulosic nanofibers showed high extraction efficiency (80–90%) towards silver (Ag) and gold (Au) nanoparticles. The maximum adsorption efficiency (Q_t) towards citrate and polyvinylpyrrolidone (PVP) capped Ag-nanoparticles using chitosan coated cellulose nanofibers was 13.1 mg g⁻¹. Similarly, Q_t values for citrate and PVP capped Au-nanoparticles were 17.9 mg g⁻¹ and 17.4 mg g⁻¹, respectively. The adsorption of nanoparticles onto the nanofibers was confirmed using scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX). Even though we used spiked solutions for the current study, it is expected that such low cost, highly abundant nanofibers may be used for setting up a large-scale nanoparticle removal system for water purification.