Green synthesis process of a polyurethane-silver nanocomposite having biocide surfaces

Abstract

Silver nanoparticles were prepared by microwave irradiation of a silver nitrate (AgNO 3 ) aqueous solution in poly(ethylene glycol) (PEG) in the absence of other chemicals. Optimal monodispersed, stable and spherical silver nanoparticles with 35 ± 5 nm diameter were obtained after 20 min of microwave irradiation at 120 1C in the presence of PEG 2000. Polyurethanes (PUs) containing silver (Ag) nanoparticles (35 nm, 1 Â 10 À3 -3 Â 10 À3 wt-%) were then prepared by introducing the nanoparticles suspension at different times of the waterborne PU synthesis. The Ag nanoparticles were found to be well dispersed in PU when introduced initially with the reagents. In these conditions, the PEG was well chemically linked to the PU chains and the presence of Ag nanoparticles didn't impact the thermo-mechanical properties of the PU. The prepared silver nanoparticles exhibited biocidal properties against Pseudomonas aeruginosa and Enterococcus faecalis both in liquid suspension and on the PUs surfaces.

Enhancing the antimicrobial activity of natural extraction using the synthetic ultrasmall metal nanoparticles

“…This can be attributed to the advantages of NPs and the limitation of Catechin. Catechin- Cu nanoparticle had a size of 5.3 ± 0.1 nm that can be easier attach to the surface of bacteria 22 and the positive surface charge on Catechin- Cu nanoparticles facilitates a direct interaction between the particles 23 and the negatively charged bacteria membranes. In addition, S. aureus , a strain representing Gram-positive bacteria, exhibited a lower survival rate in comparison to the E. coli strain and was hence lower resistant to the antibacterial effect of the Catechin- Cu nanoparticles.…”

Biobased polyurethanes for biomedical applications

“…Regarding antibacterial properties, silver NPs are largely used due to their excellent antibacterial and bactericidal properties. Despite their cytotoxicity, in low concentration they are found non-toxic in vitro [ 117 ]. Moreover, silver NPs prepared by in situ reduction of silver ion, usually in form of silver nitrate [ 118 , 119 ], to particles results in better NP distribution homogeneity inside PU matrix [ 111 , 117 , 120 ].…”

Novel Waterborne Polyurethane Adhesives Based on Ag@SiO2Nanocomposites

“…Some authors [12,13,[25][26][27] have referred to the fact that nanometric silver is not ''free'' in the polyurethane matrix, as it forms several complex structure polyurethane-Ag-polyurethane through C = O, CN, NH groups, which could explain the changes in the FTIR spectrum of the polyurethane containing silver nanoparticles (WPU-100AgNPs). In the case of the Ag@SiO 2 nanocomposites, the silica could avoid the chemical interactions of the silver with the polyurethane matrix.…”

“…There are some papers about the use of AgNPs in waterborne adhesives [12][13][14] and also about the synthesis of silver-silica nanocomposites [5,10,11,15]; however, no literature was found which combines the use of silver-silica nanocomposites to confer antimicrobial properties to waterborne polyurethane adhesives. Therefore, the main objective of this study is the synthesis of AgNPs@silica composites and the evaluation of the properties of waterborne polyurethane adhesives (WPU) based on AgNPs@silica nanocomposites, as well as the possible interactions between silver nanocomposites and the polyurethane matrix.…”