Silver Nanocomposites Research Articles

Electrical conductivity and morphological observation of hybrid filler: Silver-graphene oxide nanocomposites for wearable antenna

Copper was formerly used for the antenna conductive patch, which was expensive, subject to multipath fading, bulky, ecologically sensitive, and difficult to manufacture. The miraculous nanotechnology of graphene has made it a feasible contender to replace copper due to its extraordinary electrical conductivity and greater strength compared to metal, all while being adaptable and flexible. As a consequence, graphene is utilized in this study to create conductive silver nanocomposites. The electrical conductivity of pressed pellets of the silver-graphene (Ag/GO) sample is measured using the four-point probe method, resulting in an electrical conductivity value of approximately 21.386 S/cm. The proposed wearable antenna is designed, measured, and fabricated, consisting of a circular patch embedded with four slots to enhance the impedance bandwidth, resonating at 2.45 GHz. Besides, the wearable antenna has achieved a high gain of 11.78 dBi and a return loss of more than −20 dB. In consideration of health and safety concerns in wearable devices, the specific absorption rate (SAR) is evaluated. The SAR is determined to be 0.9 W/kg per 10 g of tissue for an input power of 0.5 W, confirming the safety of the proposed graphene wearable antenna for use in wearable devices. These findings suggest promising prospects for the utilization of Ag/GO nanocomposites as a conductive patch for wearable antennas in wireless communication.

Preparation of photo-grafted magnetic nano-silver composites and their catalytic studies on organic dyes

More active and stable catalyst is needed for degradation of organic dyes in wastewater. A new kind of polymethyl methacrylate (PMMA) microsphere hybridized with Ag and Fe3O4 was developed as catalyst. PMMA microspheres were prepared by photoinitiated dispersive polymerization, and then acrylic acid (AA) was photo-grafted on the surface of microspheres with 365 nm UV light to prepare PMMA-AA microspheres whose carboxyl group was up to 164 × 1021 per microsphere. Under the effect of NaBH4, the Ag nanoparticles on the surface of PMMA and PMMA-AA microspheres were successfully modified with the help of carboxyl groups on the surface of PMMA and PMMA-AA microspheres. Fe3O4 particles were adsorbed onto the microsphere surface to obtain two kinds of microspheres (PMMA@Ag@Fe3O4, PMMA-AA@Ag@Fe3O4) for the catalytic reduction of methylene blue (MB) and rhodamine B (Rh-B), respectively. PMMA-AA@Ag@Fe3O4 microspheres exhibited excellently catalytic performance that the apparent rate coeffcients of MB and Rh-B were 0.045 s−1 and 0.036 s−1 respectively. The catalytic efficiency of PMMA-AA@Ag@Fe3O4 heterogeneous catalyst can reach 90% even after 8 cycles for MB. It has excellent catalytic performance, high non-selective adsorption and good reusability. Excellent catalytic performance, high non-selective adsorption and reusability even in the presence of mixed dyes.

Assessment of olive leaf extract–mediated chitosan–silver nanocomposites as antibacterial and biocorrosion mitigation agents

Assessment of olive leaf extract–mediated chitosan–silver nanocomposites as antibacterial and biocorrosion mitigation agents

Photocatalytic Dye Degradation Potential of Silver Nanocomposite from Exo-polysaccharide of Bacillus sp., An Associative Bacterium of Sargassum wightii

Photocatalytic Dye Degradation Potential of Silver Nanocomposite from Exo-polysaccharide of Bacillus sp., An Associative Bacterium of Sargassum wightii

Sensing platform for the highly sensitive detection of catechol based on composite coupling with conductive Ni3(HITP)2 and nanosilvers.

Catechol, which has a high toxicity and low degradability, poses significant risks to both human health and the environment. Tracking of catechol residues is essential to protect human health and to assess the safety of the environment. We constructed sensing platforms to detect catechol based on the conductive metal-organic frameworks [Ni3(HITP)2] and their nanosilver composites. The reduction process of catechol at the Ni3(HITP)2/AgNP electrode is chemically irreversible as a result of the difference in compatibility of the oxidation stability and conductivity between the Ni3(HITP)2/AgNS and Ni3(HITP)2/AgNP electrodes. The electrochemical results show that the Ni3(HITP)2/AgNS electrode presents a lower detection limit of 0.053 μM and better sensitivity, reproducibility and repeatability than the Ni3(HITP)2/AgNP electrode. The kinetic mechanism of the catechol electrooxidation at the surface of the electrode is controlled by diffusion through a 2H+/2e- process. The transfer coefficient is the key factor used to illustrate this process. During the electrochemical conversion of phenol to ketone, more than half of ΔG is used to change the activation energy. We also studied the stability, anti-interference and reproducibility of these electrode systems.

Green synthesis and characterisation of silver nanocomposites and nanoparticles derived from banana leaves

Green synthesis and characterisation of silver nanocomposites and nanoparticles derived from banana leaves

A selective colorimetric and efficient removal strategy for mercury(II) in aquatic systems using mesoporous Fe3O4-loaded silver probes.

Mesoporous Fe3O4-loaded silver nanocomposites (Fe3O4@Ag) were simply fabricated as bi-functional nanozymes for the catalysis-based detection and removal of Hg2+ ions. It was found that the as-prepared magnetic Fe3O4@Ag could display peroxidase-like catalysis activity that could be rationally enhanced in the presence of Hg2+ ions. To our surprise, the shell of the Ag element may decrease the catalysis of the Fe3O4 to some degree. However, the Ag particles could serve as the probes for specifically recognizing Hg2+ ions and trigger increased catalysis through the formation of Ag-Hg alloys, with a decreased signal background. A high-throughput colorimetric analytical method was thereby developed based on the Fe3O4@Ag catalysis for probing Hg2+ ions in the muscles of fish by using 96-well plates, at linear Hg2+ concentrations ranging from 0.010 to 2.5 mg kg-1. Moreover, the developed colorimetric analytical method was applied to evaluate Hg2+ levels in muscle samples of different kinds of fish. Unexpectedly, an obvious difference of Hg2+ levels in muscles of four kinds of fish was discovered, with the order of snakehead (Ophicephalus argus) > largemouth bass (Micropterus salmoides) > crucian carp (Carassius auratus) > silver carp (Hypophthalmichthys molitrix), where the carnivorous fish showed higher Hg2+ levels than the omnivorous or plant-based ones. Moreover, the as-fabricated Fe3O4@Ag adsorbents with their large specific surface area and high environmental robustness could exhibit efficient Hg2+ adsorption with capacities of up to 397.60 mg g-1. A removal efficiency of 99.40% can also be expected for Hg2+ ions from wastewater, with the magnet-aided recycling of Fe3O4@Ag adsorbents. Such an Fe3O4@Ag-based colorimetric analysis and removal strategy for Hg2+ ions should find wide applications in the fields of aquatic food safety, environmental monitoring, and clinical diagnostics of Hg-poisoning diseases.

Synthesis, characterization and application of silk sericin-based silver nanocomposites for antibacterial and food coating solutions.

The rising demand for fresh and safe food is driving advancements in preservation technologies, with nanoparticles offering a revolutionary solution. These particles extend shelf life, preserve nutritional value, and enhance food safety, aligning with present consumer expectations. This study explores the eco-friendly synthesis, characterization, and application of silk sericin-based silver nanoparticles (SS-AgNPs) for antibacterial and food coating purposes. Silk sericin, a byproduct of the silk industry, is typically discarded despite its valuable properties like biocompatibility, biodegradability, and antimicrobial activity. In this research, sericin from Bombyx mori cocoons was used as a reducing and stabilizing agent to synthesize SS-AgNPs. Characterization was performed using UV-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and dynamic light scattering (DLS). Antibacterial tests confirmed the efficacy of SS-AgNPs against Pseudomonas sp. and Staphylococcus sp., while food coating trials on tomatoes significantly reduced weight loss and microbial contamination. Biocompatibility was further verified through hemolysis and MTT assays, confirming SS-AgNPs' safety for biomedical and food-related uses. This study underscores the potential to convert sericin waste into a valuable resource, promoting sustainability and increasing the commercial value of sericulture.

Green synthesis and characterisation of silver nanocomposites and nanoparticles derived from banana leaves

Green synthesis and characterisation of silver nanocomposites and nanoparticles derived from banana leaves

Solid polymer electrolyte and antimicrobial performance of Polyvinyl alcohol/Silver nanoparticles composite film

A nanocomposite based on polyvinyl alcohol (PVA) is developed using silver nanoparticles (Ag NPs) prepared by the chemical reduction method. The nanocomposite is analyzed by X-ray diffraction method (XRD) and Fourier transform infrared (FTIR) analyses. XRD analysis confirms the purity of the synthesized silver nanoparticles with the average crystallite size of 15 nm. It also shows the presence of nanoparticles in the nanocomposite films. The interaction of silver nanoparticles with the polymer matrix is demonstrated by the FTIR spectrum. Scanning electron microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDAX) and UV–Visible spectroscopy confirm the formation of silver nanoparticles with spherical morphology and surface Plasmon resonance at 424 nm. Further, nanocomposite as solid polymer electrolyte and antimicrobial properties of the nanocomposite are illustrated. The addition of nanoparticles increases the electrical conductivity (1.7866 × 10-6 Scm−1) of the PVA silver nanocomposite film that is measured from electrochemical impedance spectroscopy through Cole-Cole plots. The PVA/Silver nanoparticles composite films show a high zone of inhibition for both Gram-negative and Gram-positive bacteria than pure PVA films. The electrochemical performance shows the ability to use as a solid polymer electrolyte in electrochemical devices. Polyvinyl alcohol (PVA)/Silver nanoparticles composite films with high anti-bacterial activity can be used for wound dressings and active food packaging.

Retracted: Preparation of Graphene Nanosilver Composites for 3D Printing Technology

Retracted: Preparation of Graphene Nanosilver Composites for 3D Printing Technology

Biological Synthesis and Characterization of Silver-Doped Nanocomposites: Antibacterial and Mechanistic Studies

The development of antimicrobial resistance has increased the prevalence of infectious diseases, causing a global health problem that accounts for over 4.95 million deaths worldwide annually. The side effects associated with current antibiotics prompt a crucial need to search for effective and safe antimicrobial agents. In this study, silver nanoparticles (AgNPs) were prepared by chemical reduction method using silver nitrates as a metallic precursor and Croton macrostachyus bark aqueous extract as a reducing and capping agent. The nanoparticles were further functionalized using C. macrostachyus-based activated carbon (CAC) to generate nanocomposites (CAC-AgNPs). The nanomaterials were characterized by ultraviolet-visible (UV–vis) absorption spectra and Fourier transform infrared (FTIR) spectra. The antibacterial activity of the as-prepared nanomaterials was evaluated against an array of bacterial strains by microdilution method, whereas their cytotoxicity profile was evaluated using Vero cells (human mammalian cells). Antibacterial mechanistic studies of active nanomaterials were carried out through bacterial growth kinetics, nucleic acid leakage tests, and catalase inhibition assays. As a result, the as-prepared nanomaterials exhibited antibacterial activity against an array of bacterial strains (minimum inhibitory concentration (MIC) range: 62.5 to 500 µg/mL), the most susceptible being Escherichia coli and Staphylococcus aureus. Cytotoxicity studies of the nanomaterials on Vero cells revealed that the nanocomposite (median cytotoxic concentration (CC50): 213.6 µg/mL) was less toxic than its nanoparticle (CC50 value: 164.75 µg/mL) counterpart. Antibacterial mechanistic studies revealed that the nanomaterials induced (i) bacteriostatic activity vis à vis E. coli and S. aureus and (ii) inhibition of catalase in these bacteria. This novel contribution regarding the antibacterial mechanisms of action of silver nanocomposites from C. macrostachyus-based activated carbon may contribute to our understanding of the antibacterial action of these biomaterials. Nevertheless, more chemistry and in vivo experiments as well as in depth antibacterial mechanistic studies are warranted for the successful utilization of these antibacterial biomaterials.

Graphene based hydrogel silver nano-composites for antibacterial and antitumor applications: In vitro evaluation

Graphene based hydrogel silver nano-composites for antibacterial and antitumor applications: In vitro evaluation

Establishment and inactivation of mono-species biofilm in a semipilot-scale water distribution system using nanocomposite of silver nanoparticles/montmorillonite loaded cationic chitosan

This study presents a novel approach in the synthesis and characterization of nanocomposites comprising cationic chitosan (CCS) blended with varying concentrations of silver nanoparticles/montmorillonite (AgNPs/MMT). AgNPs/MMT was synthesized using soluble starch as a reducing and stabilizing agent. Subsequently, nanocomposites, namely CCS/AgMMT-0, CCS/AgMMT-0.5, CCS/AgMMT-1.5, and CCS/AgMMT-2.5, were developed by blending 2.5 g of CCS with 0, 0.5, 1.5, and 2.5 g of AgNPs/MMT, respectively, and the corresponding nanocomposites were prepared using ball milling technique. Transmission electron microscopy (TEM) analysis revealed the formation of nanocomposites that exhibiting nearly spherical morphologies. Dynamic light scattering (DLS) measurements displayed average particle sizes of 1183 nm, 131 nm, 140 nm, and 188 nm for CCS/AgMMT-0, CCS/AgMMT-0.5, CCS/AgMMT-1.5, and CCS/AgMMT-2.5, respectively. The narrow polydispersity index (~0.5) indicated uniform particle size distributions across the nanocomposites, affirming monodispersity. Moreover, the zeta potential values exceeding 30 mV across all nanocomposites that confirmed their stability against agglomeration. Notably, CCS/AgMMT-2.5 nanocomposite exhibited potent antibacterial and antibiofilm properties against diverse pipeline materials. Findings showed that after 15 days of incubation, the highest populations of biofilm cells, Pseudomonas aeruginosa biofilm, developed over UPVC, MDPE, DCI, and SS, with corresponding HPCs of 4.79, 6.38, 8.81, and 7.24 CFU/cm2. The highest cell densities of Enterococcus faecalis biofilm in the identical situation were 4.19, 5.89, 8.12, and 6.9 CFU/cm2. The nanocomposite CCS/AgMMT-2.5 exhibited the largest measured zone of inhibition (ZOI) against both P. aeruginosa and E. faecalis, with measured ZOI values of 19 ± 0.65 and 17 ± 0.21 mm, respectively. Remarkably, the research indicates that the youngest biofilm exhibited the most notable rate of inactivation when exposed to a dose of 150 mg/L, in comparison to the mature biofilm. These such informative findings could offer valuable insights into the development of effective antibiofilm agents and materials applicable in diverse sectors such as water treatment facilities, medical devices, and industrial pipelines.

Novel evolution of gamma irradiated PVP/Cu–Ag nanocomposite for dye polluted water treatment

A novel polyvinylpyrrolidone/copper–silver (PVP/Cu–Ag) nanocomposite was synthesized via aqueous solution reduction and gamma radiation techniques for the treatment of methylene blue dye (MB) polluted water as a common organic dye pollutant in wastewater which is harmful to human health and aquatic life. Different analyses were used for the characterization of the synthesized Cu–Ag nanoparticles (NPs) and PVP/Cu–Ag nanocomposites such as XRD, TEM, DLS, FTIR, EDX, and TGA The XRD results indicated the typical peaks of CuNPs and AgNPs and the formation of pure crystalline nanoparticles in addition to their corresponding peaks were noticed in the PVP/Cu–Ag nanocomposite. Results of FTIR for the PVP/Cu–Ag nanocomposite confirmed the successful interaction between Cu–Ag NPs and PVP chains. The SEM of the PVP/Cu–Ag nanocomposite appeared rough and dense porous surface with white spots of Cu–Ag nanoparticles that dispersed homogeneously all over the surface of the PVP matrix. The effect of the dose of gamma radiation on the gelation and swelling of PVP hydrogel and PVP/Cu–Ag nanocomposite was studied. Using 15 kGy, the gel content of 89% and 97.1% for PVP and PVP/Cu–Ag, respectively. The swelling degree of PVP/Cu–Ag nanocomposite shows pH dependence and the maximum swelling was at pH 6. The point of zero charge (pHpzc) of PVP/Cu–Ag nanocomposite was 5.8. The factors affecting the removal of MB dye were evaluated as the effect of reaction time, dosage, temperature, pH, and dye concentration. The PVP/Cu–Ag nanocomposite shows fast adsorption of MB dye with a removal percentage of 95% after 50 min, at pH 8, 200 mg/L dye concentration, and 0.1 g nanocomposite dosage. Based on the kinetic, isotherm, and thermodynamic studies, it was found that the adsorption of MB dye onto PVP/Cu–Ag nanocomposite fitted to the Pseudo-second-order kinetic model and the Langmuir isotherm model and the reaction was an endothermic, spontaneous, and chemisorption. The fast removal of the dye using the PVP/Cu–Ag nanocomposite confirms its possible use in wastewater treatment applications as an effective adsorbent for dye treatment.

Influence of preparation method on the structure, morphology, and conducting property of poly(m‐aminophenol)/silver nanocomposite

AbstractThe aim is to create a nanocomposite with well‐defined morphology having enhanced electronic characteristics, suitable for a diverse range of applications including sensors, supercapacitors, and electrode materials, among others. A composite consisting of the functional conjugated polymer, such as poly(m‐aminophenol), combined with silver nanoparticles, can be fabricated by meticulously regulating its structure, morphology, and properties. In the current research, three different morphologies, viz., nanoparticles distributed, nanofibrous, and core–shell were obtained following three different methods of preparation. The nanocomposite with a uniform distribution of 5.15 wt% small silver nanoparticles exhibited the highest average DC conductivity of 1.3 × 10−4 S cm−1. However, the nanofibrous composite with 2.79 wt% silver loading and core–shell nanocomposite with 5.59 wt% silver loading were found to have poor conductivities in order of 10−7 S cm−1. The electronic conduction of the nanocomposites prepared in three different methods was correlated with the structural features of the polymer matrix and the interfacial interaction between the components. This suggests that the nanocomposites with uniform distribution of small silver nanoparticles hold high potential as electronic material for a wide range of applications.Highlights Optimization of preparation of poly(m‐aminophenol)/silver nanocomposite. Investigation of structure and morphologies of the composites. Morphologies—nanocomposites, nanofiber composite, and core–shell composite. Highest average DC‐conductivity of nanocomposite obtained as 1.3 × 10−4 S cm−1. Conductivity in order of 10−7 S cm−1 was observed for the other two nanocomposites.

Angular surface plasmon resonance-based sensor with a silver nanocomposite layer for effective water pollution detection

For sensing various samples of polluted water and various sodium chloride concentrations using an angular surface plasmon resonance (ASPR), we have introduced a conventional structure and a hybrid heterostructure in the current research. The suggested structures are composed of silver metal, dielectric layers, silver nanocomposite, and a sensing medium. The reflectance spectra of all structures in the visible region were obtained through the utilization of the transfer matrix method by using the angular interrogation method depending on the Kretschmann configuration. Through our findings, five substrate parameters have been optimized to attain the utmost level of sensitivity across all structures: the thickness of Ag-metal, the type and thickness of dielectric materials, the host material type and the volume fraction of nanoparticles for the nanocomposite layer. In this regard, the suggested sensor provides excellent performance with a sensitivity of 448.1°/RIU\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$/\ ext{RIU}$$\\end{document}, signal-to-noise ratio of 0.787, sensor resolution of 0.284°, and figure of merit of 78.766 RIU−1. Therefore, we believe that the introduced design of our ASPR sensor presents a good candidate for an accurate and efficient detection of low concentrations of contaminated water and sodium chloride as well.

Active biosoluble composite material obtained by real-time LbL photoreduction of silver via light-based 3D printing

In this study, a silver-containing photopolymerizable resin was developed and synthesized to create an active biosoluble composite for various applications, including biomedical devices. The main goal was to investigate the properties of this material, which can be produced through real-time LbL (Layer-by-Layer) in situ silver photoreduction during resin photopolymerization. This process uses the 405 nm LEDs of an MSLA (Masked Stereolithography Apparatus) 3D printer. Characterization techniques reveal chemical changes caused by the photoreduction of silver as well as an improvement in physical properties attributed to the presence of metallic silver. The silver nanocomposite has the potential for applications such as 3D-printed antimicrobial structures for biomedicine and engineering. To demonstrate the application of the developed material, a PoC (Proof of Concept) of 3D printing of bioinspired microneedles is presented, aiming to contribute to methods of drug administration that bypass the stratum corneum without causing pain.

Antifungal Properties of Graphene Silver Nanocomposites against Candida Sp.

Antifungal Properties of Graphene Silver Nanocomposites against Candida Sp.

Fabrication of chitosan/fibrin-armored multifunctional silver nanocomposites to improve antibacterial and wound healing activities

A wound healing substitute promotes rapid tissue regeneration and protects wound sites from microbial contamination. The silver-based antiseptic frequently moist skin stains, burns and irritation, penetrates deep wounds and protects against pathogenic infections. Thus, we formulated a novel fibrin/chitosan encapsulated silver nanoparticle (CH:F:SPG-CH:SNP) composites bandage accelerating the polymicrobial wound healing. Electrospinning method was employed to form the nano-porous, inexpensive, and biocompatible smart bandages. The structural, functional, and mechanical properties were analyzed for the prepared composites. The biological capacity of prepared CH:F:SPG-CH:SNP bandage was assessed against NIH-3 T3 fibroblast and HaCaT cell lines. In vitro hemolytic assays using red blood cells were extensively studied and explored the low hemolytic effect (4.5 %). In addition, the improved drug delivery nature captured for the CH:F:SPG-CH:SNP composite bandage. Antibacterial experiments were achieved against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Lactobacillus bulgaricus using zone inhibition method. Moreover, in-vivo wound healing efficacy of fabricated smart bandage was evaluated on the albino Wistar rats which revealed the significant improvement on the postoperative abdomen wounds.