Formulation of epoxy–polyester powder coatings containing silver-modified nanoclays and evaluation of their antimicrobial properties

Abstract

Current interest in antimicrobial coatings is driven by an urgent need for more effective strategies to control microbial infection. In this study, antimicrobial nanoclays were prepared by ion-exchange of sodium montmorillonite (MMT) with silver ions which have been previously reported to exhibit biocidal activity. The extent of ion exchange achieved was estimated by x-ray photoelectron spectroscopy (XPS). The silver-modified nanoclay (AgMMT) fully inhibited growth of Gram negative Escherichia coli DH5α (E. coli) over 24 hours;annealing AgMMT under typical conditions used to prepare polymer composites did not reduce its antimicrobial efficacy. However, powder coatings of AgMMT dispersed in epoxy/polyester resin exhibited no antimicrobial effect E. coli. This is believed to be caused by poor wetting of the polymer coating, which restricted the diffusion of silver ion from the coating.

Synthesis and application of silver nanoparticles loaded on modified montorillonite

“…A high-resolution scan of Ag 3d (Fig. 2) was composed of a doublet corresponding to 3d 5/2 and 3d 3/2 ; a similar situation was also reported by Armstrong et al [9]. The Ag 3d 5/2 signal at 368.22 eV corresponds to Ag + ions [10], whereas that occurring at 368.4 is related to metallic Ag 0 [11].…”

An introduction to polymer nanocomposites

“…Approach 1: Formulation of epoxy-polyester powder coatings containing silver-modified nanoclays (Armstrong et al 2012) Approach 2: Synthesis of titania-silver and alumina-silver composite nanoparticles and formulation into silicone and epoxy nanocomposites (Bala et al 2011) Approach 1: Formulation of epoxy-polyester powder coatings containing silver-modified nanoclays Sodium montmorillonite nanoclay was modified with both silver nitrate and quaternary ammonium surfactant (following the approach described in Figure 9) to achieve antimicrobial properties and mixing with epoxy matrix. The resulting nanoclay was then characterised by XRD to assess the change in gallery spacing (Smart and Moore 1995b) and x-ray photoelectron spectroscopy (XPS) (Moulder et al 1992) to determine whether there were silver ions present on the nanoclay surface as desired.…”

High performance epoxy/polyester-based nanocomposite coatings for multipurpose applications: A review

“…77 Rai et al 78 studied silver nanoparticles in antimicrobial coatings. Armstrong et al 79 prepared silver-modified nanoclay as a filler for epoxy-based coatings. The antimicrobial coatings were used to inhibit Gram-negative bacterium Escherichia coli growth.…”