Microfibrillated Cellulose-silver Nanocomposite Based PVA Hydrogels and Their Enhanced Physical, Mechanical and Antibacterial Properties

Modification of cellulose with silver nanoparticles produces various nanocomposites with significantly developed properties. This work aims to prepare a PVA hydrogel modified with cellulose/silver nanocomposites having potential applications in various fields including biomedical, antimicrobial inhibition, textile wears, etc. Microfibrillated cellulose/silver nanocomposites hydrogels were prepared in the aqueous medium with aid of microwave-assisted heating. Different percentages of nanocomposites were incorporated in PVA hydrogel to enhance the properties of PVA hydrogel. Prepared products were characterized by UV-Visible spectroscopy, FTIR, TGA, XRD, and SEM. The swelling (in water saline, acidic and alkaline solution), tensile, thermal, and antibacterial properties were also examined. The formation of Ag nanoparticles (AgNPs) in the (MFC-Ag) NC was confirmed by XRD and UV–Vis spectra. UV–Vis spectra showed the characteristic peaks of Ag in the UV–Vis spectra at 425 nm. Final products exhibited significant porosity and maximum swelling of 519.44%. The thermal stability of hydrogel increased with an increased percentage of (MFC-Ag)NC. Hydrogels exhibited significant antimicrobial inhibition against multidrug-resistant microorganisms, including Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.

Silver Nanoparticulate Matter Reinforced Conducting Polymer Polyaniline Nanocomposite: Sol-Gel Processing, Schottky-Diode Making and Electronic Worthiness Testing

Polyaniline nanoparticles is synthesized by chemical oxidation of aniline by copper sulphate. Chemical reduction of silver nitrate by sodium citrate yileds silver nanoparticles. Both aforesaid nanomaterials are mixded with polyvinyl alcohol to get nanocomposite gel. Nanoparticles are characterized by ultraviolet-visible absorption spectroscopy. Schottky diode is made by applying nanocomposite with copper wire on one side of aluminium foil and on other side attaching copper wire for another electrical contact. Current-voltage electrical characterization is analyzed by making simple circuit encompassing polyaniline/silver nanocomposite diode. Keywords: Nanoelecttronics, Nanoparticles, Polyaniline, Nanocomposite, Schottky-diode

Electromagnetic interference shielding effectiveness of polypyrrole-silver nanocomposite films on silane-modified flexible sheet

The conventional electromagnetic interference (EMI) shielding materials are being gradually replaced by a new generation of supported conducting polymer composites (CPC) films due to their many advantages. This work presents a contribution on the effects of silane surface–modified flexible polypyrrole-silver nanocomposite films on the electromagnetic interference shielding effectiveness (EMI-SE). Thus, the UV-polymerization was used to in-situ deposit the PPy-Ag on the biaxial oriented polyethylene terephthalate (BOPET) flexible substrates whose surfaces were treated by 3-aminopropyltrimethoxysilane (APTMS). X-ray Photoelectron Spectroscopy (XPS) analyzes confirmed the APTMS grafting procedure. Structural, morphological, thermal, and electrical characteristics of the prepared films were correlated to the effect of substrate surface treatment. Thereafter, EMI-SE measurements of the elaborated films were carried out as per ASTM D4935 standard for a wide frequency band extending from 50 MHz to 18 GHz. The obtained results confirmed that the APTMS-treated BOPET film exhibit higher EMI shielding performance and better electrical characteristics compared to the untreated film. In fact, a 32% enhancement of EMI-SE was noted for the treated films compared to the untreated ones. Overall, these results put forward the role played by the surface treatment in strengthening the position of flexible PPy-Ag supported films as high-performance materials in electronic devices and electromagnetic interference shielding applications.

Application of Green Synthesized MMT/Ag Nanocomposite for Removal of Methylene Blue from Aqueous Solution

Textile industries are the largest consumer of synthetic dyestuff compounds and consequently, they are the prime contributor of colored organic contaminants to the environment. The dye compounds when released in soil or freshwater resources such as rivers, cause a potential hazard to living beings due to their toxic, allergic and carcinogenic nature. Current conventional treatment methods for removal or degradation of such dyestuff materials from water systems are not sufficient, and therefore, there is an immediate need to find efficient and eco-friendly approaches. In this regard, nanotechnology can offer an effective solution to this problem. In the present work, montmorillonite/silver nanocomposite (MMT/Ag nanocomposite) is developed through green synthesis methods using naturally occurring montmorillonite (MMT) clay and silver nanoparticles. The material was characterized by using a particle size analyzer (PSA), UV/Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray (EDX) spectroscopy and a Brunner–Emmett–Teller (BET) surface area analyzer. The adsorption efficiency of the nanocomposite and per cent removal of methylene blue (MB) was investigated by using a batch system.

Development of Sustainable and Functional Fabrics from Recycled and Nanocomposite Polyester Fibers

Antimicrobial knitted and woven fabrics were developed from recycled polyester (PET) and silver nanocomposite (SNC) fibers. Two different fabrics were produced from two different blend proportions of the fibers. The antimicrobial properties of fabrics were tested against those of the S. aureus (Gram-positive) and E. coli (Gram-negative) bacterial natures, and their yarn properties and hand-related characteristics were investigated. The results show uneven fabrics properties such as irregularity in thickness and SNC-recycled PET fiber ratio increase, and the tensile strength decreases while the NEP number increases. This implies that fabrics made from a blend with higher SNC-recycled PET fiber ratios have higher surface roughness levels, higher bending rigidity, and harder texture. As a consequence, the antimicrobial efficiency of the fabrics was improved as the percentage of SNC increased. The recycled PET fiber within the blended yarn shows a good antimicrobial property (above 90%) observed in all fabrics. The reduction of bacterial colonies was constantly exceeding 90% for both E. coli and S. aureus in all fabric samples.