Issue 8, 2020

Hierarchically aligned nano silver/chitosan–PVA hydrogel for point-of-use water disinfection: contact-active mechanism revealed

Abstract

The unsafe disposal of biomedical waste poses hazardous consequences to natural water resources, which may get contaminated through several means of leakage into waterways. Herein, the disinfection potential of nano-silver loaded chitosan–PVA hydrogel to completely eradicate biomedical contaminants coexisting with natural contaminants in environmental samples was successfully demonstrated for the first time. The polymeric network of the hydrogel served a dual role for in situ synthesis and immobilization of silver nanoparticles (AgNPs) simultaneously. Porous Ag-loaded hydrogels displayed a temperature-dependent swelling behavior and exhibited an improved mechanical strength (Young's modulus, 12.36 ± 0.29 MPa; elongation at break, 180%) by effectively distributing the external stress and restored its structural integrity. Complete disinfection (100% killing) could be achieved within 4 h against all the four tested contaminants, demonstrating a distinct strain-specific biocidal activity. Being a diffusion-controlled process, the oxidative dissolution of AgNPs deeply buried in the interiors of the hydrogel architectures was adversely affected on repeated use and restricted the maximum silver release to 38.8 ± 5.6 μg g−1 hydrogel in an aqueous suspension over 7 days. Correlating the reusability and silver release kinetics, a predominant contact-active role of the hydrogel was envisaged via ‘capture and kill’ over leaching of silver ions for rapid water disinfection. The Ag-loaded hydrogels also severely inhibited the biofilm formation of Escherichia coli and Staphylococcus aureus till 48 h. Finally, the hydrogels could completely disinfect the natural water samples, i.e., river, ground, and tap water with inherited microbiota and biomedical contaminants in 2 h under the real conditions.

Graphical abstract: Hierarchically aligned nano silver/chitosan–PVA hydrogel for point-of-use water disinfection: contact-active mechanism revealed

Supplementary files

Article information

Article type
Paper
Submitted
19 avr. 2020
Accepted
11 juin 2020
First published
11 juin 2020

Environ. Sci.: Nano, 2020,7, 2337-2350

Hierarchically aligned nano silver/chitosan–PVA hydrogel for point-of-use water disinfection: contact-active mechanism revealed

N. K. Dhiman and S. Agnihotri, Environ. Sci.: Nano, 2020, 7, 2337 DOI: 10.1039/D0EN00405G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements