Poly(dimethylsiloxane)-containing thermoplastic elastomer/gold-silver alloy nanocomposites for thermally/oxidatively stable and antimicrobial coating

Abstract

Polymer materials with embedded silver (Ag) nanoparticle (NP) are of considerable interest owing to their enhanced antimicrobial activity and physical properties compared to host polymer. Antimicrobial and thermally/oxidatively stable coating not only enhances the durability of the coated material but also reduces the growth of bacteria/fungus and thus reduces the chance of infection. For this purpose, we have prepared polydimethylsiloxane‐containing predominantly poly(meth)acrylates‐based pentablock thermoplastic elastomer (TPE)/gold (Au)–Ag alloy nanocomposites (NCs) with antimicrobial activity and enhanced physical properties. In situ simultaneous reduction of appropriate amount of metal salts in the presence of block copolymer produced Au–Ag NPs of size 5–10 nm. Such embedded 5–10 nm sized particles (loading, 0.1–0.2 wt%) improved the mechanical property, thermal/oxidative stability, and antimicrobial activity of the NCs. The NC films also exhibited tunable surface wetting behavior and optical properties. The NC films showed low level of Ag leaching as confirmed by inductively coupled plasma spectrometer and UV–visible spectroscopy. Improved thermal/oxidative resistance of the TPE/Au–Ag alloy NCs enhanced antimicrobial activity, together with low level of leaching characteristic of the embedded NPs deemed suitable for further use of these NCs material for antimicrobial and oxidatively stable coating applications. POLYM. COMPOS., 36:2103–2112, 2015. © 2014 Society of Plastics Engineer

Multifunctionalization of Poly(vinylidene fluoride)/Reactive Copolymer Blend Membranes for Broad Spectrum Applications

“…PVDF/copolymer-1-Ag and PVDF/cys-1-Ag showed similar inhibition zones to those of PVDF/copolymer-2-Ag and PVDF/cys-2-Ag. The formation of inhibition zone may be explained by the leaching of even very low concentration of Ag ions as well as by contact killing mechanism. , …”

“…The formation of inhibition zone may be explained by the leaching of even very low concentration of Ag ions as well as by contact killing mechanism. 49,50 Figure 8 shows the quantification of the bacteria attachment on the surface of Ag NC membranes and membranes without Ag NP. The Ag NCs membranes showed much lower propensity toward attachment of bacteria.…”

“…Since the leaching of Ag in form of ions is negligible, most probably the contact killing mechanism is majorly responsible for the antimicrobial effect of these NC membranes. 49,50 ■ CONCLUSION Covalent functionalization of PVDF membranes was successfully accomplished through post-nucleophilic substitution reaction between activated benzyl chloride groups of PVDF blend membrane and amine groups of macromolecules. Good stability of the grafted macromolecules was realized by this method owing to covalent cross-linking.…”

Composite Anion Exchange Membranes with Antibacterial Properties for Desalination and Fluoride Ion Removal

“…Well-dispersed nanoparticles in membranes show the same optical behavior as in a solution . There are reports for the preparation of polymer nanocomposite with different nanoparticles. , Among them, the well-dispersion of silver nanoparticles (AgNPs) in polymer/membranes is very useful due to the excellent optical, electric, antibacterial properties, and low human toxicity of AgNPs. − The biofouling property of the membranes could be reduced if AgNPs are embedded in the membrane surface. , Aminated poly­(ether sulfone)-AgNPs composite membranes were used for water treatment applications . AgNPs composite membrane in a polysulfone matrix with enhanced antimicrobial property was used for water purification …”

Addition of a small amount of multiwalled carbon nanotubes and flaked graphene to epoxy resin

“…3 Since the beginning of their existence, they have been the subject of intense research aiming to apply them in many technological fields. An example of such solutions is the application of chitosan nanoplates as medicine carriers, 4 elastomer nanoparticles carrying silver/gold as antimicrobial coatings, 5 supermagnetic nanoparticles for providing different materials with magnetic properties, 6 modified nano-bentonite for the improvement of flame resistance, 7 or introduction of various nanoparticles as catalysts in chemical processes. 8 In the recent years, the most popular nano-additives have been carbon nanotubes and graphene.…”