Effect of Dispersion Solvent on the Deposition of PVP-Silver Nanoparticles onto DBD PlasmaTreated Polyamide 6,6 Fabric and Its Antimicrobial Efficiency.

Ana I Ribeiro,Mike De Vrieze,Andrea Zille,Martina Modic,Bogdana Mitu,Anton Nikiforov,Helena P Felgueiras,Gheorghe Dinescu,António P Souto,Uros Cvelbar,Christophe Leys,Iryna Kuchakova

doi:10.3390/nano10040607

Abstract

Polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) dispersed in ethanol, water and water/alginate were used to functionalize untreated and dielectric barrier discharge (DBD) plasma-treated polyamide 6,6 fabric (PA66). The PVP-AgNPs dispersions were deposited onto PA66 by spray and exhaustion methods. The exhaustion method showed a higher amount of deposited AgNPs. Water and water-alginate dispersions presented similar results. Ethanol amphiphilic character showed more affinity to AgNPs and PA66 fabric, allowing better uniform surface distribution of nanoparticles. Antimicrobial effect in E. coli showed good results in all the samples obtained by exhaustion method but using spray method only the DBD plasma treated samples displayed antimicrobial activity (log reduction of 5). Despite the better distribution achieved using ethanol as a solvent, water dispersion samples with DBD plasma treatment displayed better antimicrobial activity against S. aureus bacteria in both exhaustion (log reduction of 1.9) and spray (methods log reduction of 1.6) due to the different oxidation states of PA66 surface interacting with PVP-AgNPs, as demonstrated by X-ray Photoelectron Spectroscopy (XPS) analysis. Spray method using the water-suspended PVP-AgNPs onto DBD plasma-treated samples is much faster, less agglomerating and uses 10 times less PVP-AgNPs dispersion than the exhaustion method to obtain an antimicrobial effect in both S. aureus and E. coli.

Highlights

Silver nanoparticles (AgNPs) and their composites are some of the most used nanomaterials
Despite the better distribution achieved using ethanol as a solvent, water dispersion samples with dielectric barrier discharge (DBD) plasma treatment displayed better antimicrobial activity against S. aureus bacteria in both exhaustion and spray due to the different oxidation states of PA66 surface interacting with PVP-AgNPs, as demonstrated by X-ray Photoelectron Spectroscopy (XPS) analysis
The average size and polydispersity index (PdI) of the PVP-AgNPs in ethanol, water and water/alginate dispersions were determined by dynamic light scattering (DLS) (Table 1)

Summary

Introduction

Silver nanoparticles (AgNPs) and their composites are some of the most used nanomaterials. Several methods are used to incorporate AgNPs into fabrics and can be divided by direct AgNPs stabilization onto fabrics (pad-dry-cure, dip-coating, spin coating, electroless deposition, thermo-synthesizing, spraying, sol-gel, microwave-assisted deposition and ultrasound-assisted deposition) or using pretreatments to activate the surface (plasma treatment using different gases, UV irradiation and other physico-chemical fabric functionalization) [22,23,24,25]. These methods often consume many chemicals, energy and time; require special equipment; and the antimicrobial agents have weak adhesion to the substrate [10]. The antimicrobial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria were assessed

Materials

Antimicrobial Analyses

Results and Discussion

Reflectance

Conclusions