Antimicrobial, starch based barrier coatings prepared using mixed silver/sodium exchanged bentonite

CLEGG, Francis, BREEN, Christopher, MURANYI, P and SCHÖNWEITZ, C (2019). Antimicrobial, starch based barrier coatings prepared using mixed silver/sodium exchanged bentonite. Applied Clay Science, 179, p. 105144.

[img]
Preview
PDF
Clegg-AntimicrobialStarchBased(AM).pdf - Accepted Version
Creative Commons Attribution Non-commercial No Derivatives.

Download (1MB) | Preview
Official URL: https://www.sciencedirect.com/science/article/pii/...
Link to published version:: https://doi.org/10.1016/j.clay.2019.105144

Abstract

The effect of silver nitrate concentration, pre-washed bentonite (to remove extraneous salt) and back-exchange procedures have been explored to assess the type of silver species formed and their behaviour upon exposure to further salts. X-ray fluorescence was used to quantify the amount of silver present and whether in cation exchange sites, whereas X-ray diffraction and transmission electron microscopy identified the silver compounds present. A further objective was to assess the antimicrobial, barrier and dispersion properties of the silver/sodium bentonites when incorporated into a starch-plasticiser-clay coating used for packaging. The silver/sodium bentonites demonstrated very strong antimicrobial activity towards Escherichia coli, Kocuria rhizophila and Aspergillus niger. Incorporating just 0.03 wt% of silver/sodium bentonite in the coating (0.2 μmol/m2 Ag in dried coating with thickness of 14 μm) produced a > 4.4 log reduction against an initial loading of 2.1 × 105 CFU/object for E. coli. Water vapour barrier properties of coatings prepared on paper and containing the mixed silver/sodium bentonite were unaffected since water vapour transmission rate values of ~20–40 g/m2.day (23°C, 50% relative humidity) were maintained. Also the presence of silver did not adversely affect the clay dispersion. The Ag+ release profile from mixed silver/sodium clay upon addition of HNO3 and NaNO3 is discussed.

Item Type: Article
Uncontrolled Keywords: Civil Engineering; 04 Earth Sciences; 09 Engineering
Identification Number: https://doi.org/10.1016/j.clay.2019.105144
Page Range: p. 105144
SWORD Depositor: Symplectic Elements
Depositing User: Symplectic Elements
Date Deposited: 01 Jul 2019 11:07
Last Modified: 18 Mar 2021 01:33
URI: https://shura.shu.ac.uk/id/eprint/24777

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year

View more statistics