Preparation and characterization of poly(vinyl alcohol) cryogel‐silver nanocomposites and evaluation of blood compatibility,cytotoxicity, and antimicrobial behaviors

In this investigation, cryogels composed of poly(vinyl alcohol) (PVA) were prepared by repeated freeze‐thaw method. The prepared cryogels served as templates for producing highly stable and uniformly distributed silver nanoparticles via in situ reduction of silver nitrate (AgNO₃) using alkaline formaldehyde solution as reducing agent. The structure of the PVA/Ag cryogel nanocomposites was characterized by a Fourier transform infrared and Raman spectroscopy. The morphologies of pure PVA cryogels and PVA/Ag nanocomposites were observed by a scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The SEM analysis suggested that cryogels show a well defined porous morphology whereas TEM micrographs revealed the presence of nearly spherical and well separated Ag nanoparticles with diameter about 100 nm. XRD results showed all relevant Bragg's reflections for crystal structure of silver nanoparticles. The amount of silver in cryogel nanocomposites and thermal stability were determined by inductively coupled plasma atomic emission spectrometry (ICP‐AES) and thermogravimetric analysis measurements. Mechanical properties of nanocomposites were observed in terms of tensile strength. The antibacterial studies of the synthesized nanosilver containing cryogels showed good antibacterial activity against both gram‐negative and gram‐positive bacteria. The prepared PVA/Ag nanocomposites were also investigated for swelling and deswelling behaviors. The results reveal that both the swelling and deswelling process depends on the chemical composition of the cryogel silver nanocomposites, number of freeze‐Thaw cycles and pH and temperature of the swelling medium. The biocompatibility of the prepared nanocomposites was judged by in vitro methods of percent hemolysis and protein (BSA) adsorption. POLYM. COMPOS., 36:1983–1997, 2015. © 2014 Society of Plastics Engineer     

Preparation and characterization of acrylic acid/itaconic acid hydrogel coatings containing silver nanoparticles

Hydrogel silver nanocomposites have been used in applications with excellent antibacterial performance. Acrylic acid (AA)/itaconic acid (IA) hydrogels silver nanocomposites were prepared and applied as a coating on a textile substrate. Hydrogel matrices were synthesized first by the polymerization of an AA/IA aqueous (80/20 v/v) solution and mixed with 2‐2‐azobis(2‐methylpropionamide) diclorohydrate and N,N′‐methylene bisacrylamide until the hydrogel was formed. Silver nanoparticles were generated throughout the hydrogel networks with an in situ method via the incorporation of the silver ions and subsequent reduction with sodium borohydride. Cotton (C) and cotton/polyester (CP) textile fibers were then coated with these hydrogel silver nanocomposites. The influence of these nanocomposite hydrogels on the properties of the textile fiber were investigated by infrared spectroscopy (attenuated total reflectance), scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and antibacterial tests against Pseudomona aeruginosa and Staphylococcus aureus. The better conditions, in which no serious aggregation of the silver nanoparticles occurred, were determined. It was proven that the textiles coated with hydrogels containing nanosilver had an excellent antibacterial abilities. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2713–2721, 2013     

‘Green’ synthesis and optical properties of silver–chitosan complexes and nanocomposites

Silver nanoparticles were synthesized in a chitosan biopolymer by an in situ ‘green’ chemical procedure, using d-glucose as the reducing agent. The reaction intermediates (silver–chitosan complexes) as well as the obtained nanocomposites were investigated using transmission electron microscopy, UV–vis, FTIR and photoluminescence spectroscopy. The theoretical analysis of the UV–vis absorption of the Ag–chitosan complexes suggested that the significant contribution to the complex spectrum arises from clusters of silver containing 4–9 atoms. The absorption spectrum of the nanocomposite exhibited a strong surface plasmon resonance band at 406 nm. The photoluminescence behavior of the pure chitosan, the silver–chitosan complexes and the nanocomposites were discussed in terms of morphology and silver weight content.     

A Novel Approach to Prepare Poly(Vinyl Acetate)/Ag Nanocomposite for Effective Antimicrobial Coating Applications

Polyvinyl acetate nanocomposites were successfully prepared based on silver nanoparticles. First, silver nanoparticles were directly prepared during the in situ emulsion polymerization of vinyl acetate monomer using AgNO₃ as a source of Ag⁺ ions and poly(vinyl alcohol) was used for dual functions as emulsifier for emulsion polymerization and as a stabilizing agent, trisodium citrate (C₆H₅O₇Na₃) was used as reducing agent for Ag⁺ ions during the polymerization process. The prepared polyvinyl acetate/Ag nanocomposites were assessed using X-ray diffraction, scanning electron microscopy, Fourier transform infrared, transmission electron microscopy, and ultraviolet spectra. The antibacterial properties of the prepared polyvinyl acetate/Ag nanocomposites were investigated as antimicrobial activity against pathogenic bacteria, i.e., Staphylococcus aureus (G^+ve bacteria) and Escherichia coli (G^?ve bacteria). These polyvinyl acetate nanocomposites could be used as a promising material for enhanced and continuous antibacterial applications as coating and packaging materials.     

Antibacterial activity of silver nanoparticles prepared by a chemical reduction method

Silver nanoparticles were obtained by chemical reduction of silver nitrate in water with sodium borohydride (NaBH₄) in the presence of SDS (sodium dodecyl sulfate) as a stabilizer. The synthesized silver nanoparticles were characterized by UV-vis spectroscopy (UV-vis) and transmission electron microscopy (TEM). The formation of silver nanoparticles was confirmed from the appearance of surface plasmon absorption maxima at 400 nm by UV-vis. TEM showed the spherical nanoparticles with size in 10–20 nm. The antibacterial activity of silver nanoparticles was tested by using Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coil (E. coli). The silver nanoparticles, whose bacterial activity was dependent on the aggregation degree between particles, exhibited bacterial activity against S. aureus and E. coli.     

Development of Gelatin Based Inorganic Nanocomposite Hydrogels for Inactivation of Bacteria

In this investigation, silver nanocomposite hydrogels were developed by using acrylamide and biodegradable gelatin. Silver nanoparticles were generated throughout the hydrogel networks using in situ method by incorporating Ag⁺ ions and the subsequent treatment with sodium borohydride. The effect of gelatin on the swelling studies was investigated. The hydrogel synthesized silver nanocomposites were characterized by using Fourier transform infrared, UV–Visible spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron and transmission electron microscopy techniques. The biodegradable gelatin-based silver nanocomposite hydrogels were tested for antibacterial properties. The results indicate that these biodegradable silver nanocomposite hydrogels can be useful in medical applications, as antibacterial agents.     

Development and Characterization of Curcumin Loaded Silver Nanoparticle Hydrogels for Antibacterial and Drug Delivery Applications

The present work involves the development of curcumin loaded silver hydrogel nanocomposites based on acrylamide and 2-acrylamido-2-methyl propanesulfonic acid, as a template by redox co-polymerization in the presence of hydrophilic crosslinker N,N ¹-methylenebisacrylamide. Silver nitrate was taken as the metal precursor and sodium borohydride as a reducing agent. The formation of silver nanoparticles was monitored using UV–Vis absorption spectroscopy. The developed hydrogel silver nanocomposites (HSNC) were characterized by FTIR, UV–Vis, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. The curcumin loading and release characteristics were performed for different hydrogel systems. The developed HSNCs were evaluated for preliminary antibacterial applications.     

Hydrogel–silver nanoparticle composites: A new generation of antimicrobials

Design of consistant and eco‐friendly methods for the synthesis of silver nanoparticles (AgNPs) is a significant forward direction in the field of application of antibacterial bionanotechnology. One among the available options is hydrogel templates, which are highly useful to achieve this goal. This investigation involves the development of poly(acrylamide)/poly(vinyl alcohol) hydrogel–silver nanocomposites (HSNCs) to achieve AgNPs of ～2–3 nm size in gel networks. The nanocomposite synthesis process is quite convenient, direct, and very fast, and the obtained hydrogel AgNP composites can be used for antibacterial and wound dressing applications. All the nanocomposite aqueous solutions have shown absorption peaks at 420 nm in UV–visible absorption spectrum corresponding to the Plasmon absorbance of AgNPs. X‐ray diffraction spectrum of the HSNC exhibited 2θ values matching with silver nanocrystals. Transmission electron microscopy images of nanocomposites represent discrete AgNPs throughout the gel networks in the range of 2–3 nm. The developed nanocomposites were evaluated for antibacterial application on E. coli. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and properties of silver‐containing nylon 6 nanofibers formed by electrospinning

Nylon 6 nanofibers containing silver nanoparticles (nylon 6/silver) were successfully prepared by electrospinning. The structure and properties of the electrospun fibers were studied with the aid of scanning electron microscopy, transmission electron microscopy, energy‐dispersive spectroscopy, and X‐ray diffraction. The structural analysis indicated that the fibers electrospun at maximum conditions were straight and that silver nanoparticles were distributed in the fibers. Finally, the antibacterial activities of the nylon 6/silver nanofiber mats were investigated in a broth dilution test against Staphylococcus aureus (Gram‐positive) and Klebsiella pneumoniae (Gram‐negative) bacteria. It was revealed that nylon 6/silver possessed excellent antibacterial properties and an inhibitory effect on the growth of S. aureus and K. pneumoniae. On the contrary, nylon 6 fibers without silver nanoparticles did not show any such antibacterial activity. Therefore, electrospun nylon 6/silver nanocomposites could be used in water filters, wound dressings, or antiadhesion membranes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Silver hydroxyapatite reinforced poly(vinyl alcohol)—starch cryogel nanocomposites and study of biodegradation,compressive strength and antibacterial activity

In the present work polyvinyl alcohol‐starch/silver hydroxyapatite (PVA‐starch/AgHap) cryogel nanocomposites were prepared by successive freezing‐thawing of a blend of PVA and starch solutions to fabricate a cryogel followed by its reinforcement with silver hydroxyapatite (AgHap). The prepared macroporous cryogel nanocomposites were characterized by Infra‐red spectroscopy (FTIR), environmental scanning electron microscopy (ESEM), and particle size and charge analysis. The amylase induced enzymatic degradation of nanocomposites was studied gravimetrically in phosphate buffer saline (PBS) and effect of various parameters like chemical composition of the nanocomposite, number of freeze‐thaw cycles, and enzyme activity were assessed on the extent of degradation of the nanocomposite. The influence of chemical composition and experimental conditions like the number of freeze thaw cycles was studied on the elastic modulii of the cryogels. The in vitro cytotoxicity and antibacterial activity of nanocomposites was also evaluated against L‐529 fibroblast cells and gram positive and gram negative bacteria, respectively. POLYM. ENG. SCI., 59:254–263, 2019. © 2018 Society of Plastics Engineers     

Breathing‐in/breathing‐out approach to preparing nanosilver‐loaded hydrogels: Highly efficient antibacterial nanocomposites

The key objective of developing novel materials for hygienic living conditions is to lower the risk of transmitting diseases and biofouling. To this end, a number of silver–hydrogel nanocomposite systems are under development. In this study, we attempted a unique strategy to prepare silver‐nanoparticle‐loaded poly(acrylamide‐co‐N‐vinyl‐2‐pyrolidone) hydrogel composites. To load nanosilver particles into such a nonionic hydrogel, a novel breathing‐in/breathing‐out (BI–BO) approach was employed. As the number of BI–BO cycles increased, the amount of the silver nanoparticles loaded into these hydrogels also increased. This behavior was obvious and was confirmed by ultraviolet–visible spectroscopy and thermal analysis. Furthermore, the hydrogel–silver‐nanoparticle composites were confirmed with Fourier transform infrared spectroscopy and transmission electron microscopy studies. Antibacterial studies of these hydrogel–silver nanocomposites showed excellent results against Escherichia coli. The antibacterial activity increased with the number of BI–BO cycles, and samples that underwent three BI–BO cycles showed optimal bactericidal activity. The degree of crosslinking and the silver content had a great influence on the antibacterial efficacy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Physicochemical properties and antimicrobial activity of biocompatible carboxymethylcellulose‐silver nanoparticle hybrids for wound dressing and epidermal repair

Skin loss can be caused by accident, burn, trauma, chronic wounds, and diseases, which is severely aggravated by multidrug‐resistant bacterial infections. Soft hybrids based on biopolymers combined with silver nanoparticles (AgNPs) have potential applications as wound dressing supports and skin tissue repair. Thus, our study focused on the design, green synthesis, and comprehensive characterization of carboxymethyl cellulose (CMC–AgNP) nanocomposites for producing hydrogel membranes, with tunable physicochemical properties, cytocompatibility, and biocidal activity for potential application as wound dressing and skin repair. These nanocomposites were prepared using CMC with two degrees of carboxymethylation, distinct concentrations of citric acid (CA) crosslinker, and AgNPs by in situ chemical reduction, forming hybrid membranes by the solvent casting method. The results demonstrated that superabsorbent hydrogels were produced with swelling and degradation behaviors dependent on the concentration of CA crosslinker, degree of carboxymethylation of CMC, and content of AgNP in the matrices. Moreover, the Fourier transform infrared spectroscopy analysis evidenced that the CMC functional groups (e.g., ? COOH and ? OH) were directly involved in the chemical reactions for the formation of AgNPs and hydrogel crosslinking pathway. These nanocomposites were cytocompatible using in vitro 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyltetrazolium bromide cell viability assay with of human embryonic kidney cells. Conclusively, the CMC–AgNP nanohybrids demonstrated to be simultaneously non‐toxic combined with highly effective antibacterial activity against gram‐positive multi‐resistant wound/skin pathogens (Staphylococcus aureus) and moderate effect towards gram‐negative strains (Escherichia coli and Pseudomonas aeruginosa). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45812.     

Radiation synthesis, characterisation and antimicrobial application of novel copolymeric silver/poly(2-hydroxyethyl methacrylate/itaconic acid) nanocomposite hydrogels

Silver nanoparticles were fabricated via in situ reduction of silver nitrate embedded in swollen P(HEMA/IA) hydrogel, using gamma radiolysis method. Copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA), previously synthesised by gamma radiation for wound dressing application, were used as a carrier and a stabilising agent, while ethyl alcohol was used as a free radical scavenger. The influence of different P(HEMA/IA) hydrogels and silver salt concentrations on the size and distribution of nanoparticles was investigated. The Ag/P(HEMA/IA) nanocomposites were characterised by high resolution scanning electron microscopy, energy dispersive spectroscopy, wide-angle X-ray diffraction, UV-Vis spectroscopy and swelling measurements. Escherichia coli (Gram-negative bacterium), Staphylococcus aureus (Gram-positive bacterium) and Candida albicans (fungus) were used to prove the antimicrobial properties of Ag/P(HEMA/IA) nanocomposites. The inhibition kinetics of bacteria growth was investigated by measuring the colony-forming unit. The antimicrobial effectiveness of the Ag/P(HEMA/IA) hydrogel nanocomposite was demonstrated even at small silver concentrations. P(HEMA/IA) hydrogels containing nanosilver particles was found suitable to be used as wound dressing.     

Antibacterial performance of Ag nanoparticles and AgGO nanocomposites prepared via rapid microwave-assisted synthesis method

Silver nanoparticles and silver-graphene oxide nanocomposites were fabricated using a rapid and green microwave irradiation synthesis method. Silver nanoparticles with narrow size distribution were formed under microwave irradiation for both samples. The silver nanoparticles were distributed randomly on the surface of graphene oxide. The Fourier transform infrared and thermogravimetry analysis results showed that the graphene oxide for the AgNP-graphene oxide (AgGO) sample was partially reduced during the in situ synthesis of silver nanoparticles. Both silver nanoparticles and AgGO nanocomposites exhibited stronger antibacterial properties against Gram-negative bacteria (Salmonella typhi and Escherichia coli) than against Gram-positive bacteria (Staphyloccocus aureus and Staphyloccocus epidermidis). The AgGO nanocomposites consisting of approximately 40 wt.% silver can achieve antibacterial performance comparable to that of neat silver nanoparticles.     

Microbial levan biopolymer production and its use for the synthesis of an antibacterial iron(II,III) oxide–levan nanocomposite

Levan biopolymer is an exopolysaccharide characterized with biocompatibility and unique properties that is widely used in different industries. In this study, this biopolymer was used to synthesize a nanocomposite containing magnetic nanoparticles of iron with antibacterial effects. The effects of three factors at three levels of sucrose (5, 7, and 9 g), KH₂PO₄ (0.3, 0.5, and 0.7 g), and soy flour (3, 5, and 7 g) were evaluated to produce levan exopolysaccharide by Bacillus polymyxa PTCC1020. Nine experiments were designed with different environmental conditions via the Taguchi method. The nanoparticles of iron oxide were synthesized with the coprecipitation method. In addition, nanocomposites containing magnetic nanoparticles of iron and levan biopolymer were produced. The highest level of levan extraction was observed with conditions of 5 g of soy flour (second level), 0.7 g of KH₂PO₄ (third level), and 5 g of sucrose (first level) as 27 g/L. The Fourier transform infrared analysis and ultraviolet–visible spectroscopy showed the formation of nanocomposites containing magnetic particles of iron. The results indicate that the synthesized nanocomposites had antibacterial effects on both Escherichia coli and Staphylococcus aureus. We concluded that levan and Fe₃O₄ could be used to synthesize antibacterial nanocomposites with high potential for various industrial applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44613.     

Chemical,biological, and antibacterial characterization of silica glass containing silver and gold nanoparticles

The aim of this study has been the preparation of sol‐gel glasses with potential antibacterial properties. Bioactive glasses containing different percentages of silver and gold nanoparticles have been synthesized via the sol‐gel method. The obtained glasses have 0.5, 1, 1.5, and 2 wt% silver as well as a constant amount of gold nanoparticles (AuNP) added as colloidal solution (15 wt%). Fourier Transform Infrared (FTIR) spectroscopy was used to characterize the materials. Scanning electron microscopy (SEM) has been used to investigate the surface of each sample. Moreover, the materials have been characterized in order to verify their antibacterial activities as well as their bioactivity and cytocompatibility as a function of Ag and Au content. SEM/EDX analysis has shown that the samples are bioactive because they are able to stimulate hydroxyapatite nucleation on their surface when soaked in a simulated body fluid (SBF). WST‐8 assay of 3T3 cells, placed in contact with the material extracts, has showed that the glass does not induce cytotoxicity. Staphylococcus epidermidis and Pseudomonas aeruginosa strains have been used for the evaluation of the antibacterial properties of each sample. The experimental data have shown that all synthesized materials have antibacterial activity. However, the two bacterial strains respond differently to the materials. The data show that the presence of AuNP causes a decrease in the antibacterial activity of Ag⁺ ions.     

A novel method for preparing silver/poly(siloxane‐b‐methyl methacrylate) nanocomposites with multiple properties in the DMF‐toluene mixture solvent

A novel method for preparing silver/poly(siloxane‐b‐methyl methacrylate) (Ag/(PDMS‐b‐PMMA)) hybrid nanocomposites was proposed by using the siloxane‐containing block copolymers as stabilizer. The reduction of silver nitrate (AgNO₃) was performed in the mixture solvent of dimethyl formamide (DMF) and toluene, which was used to dissolve double‐hydrophobic copolymer, as well as served as the powerful reductant. The presence of the PMMA block in the copolymer indeed exerted as capping ligands for nanoparticles. The resultant nanocomposites exhibited super hydrophobicity with water contact angle of 123.3^° and the thermogravimetry analysis (TGA) revealed that the resultant nanocomposites with more PDMS were more heat‐resisting. Besides, the antimicrobial efficiency of the most desirable nanocomposite (Ag/PDMS₆₅‐b‐PMMA₃₀ loaded with 7.3% silver nanoparticle) could reach up to 99.4% when contacting with escherichia coli within 120 min. As a whole, the resultant nanocomposites by the integration of excellent properties of silver nanoparticles as well as siloxane‐block copolymers can be a promising for the development of materials with hydrophobic, heat‐resisting and outstanding antibacterial properties from the chemical product engineering viewpoint. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4780–4793, 2013     

Synthesis and characterization of silver/alanine nanocomposites for radiation detection in medical applications: the influence of particle size on the detection properties

Silver/alanine nanocomposites with varying mass percentage of silver have been produced. The size of the silver nanoparticles seems to drive the formation of the nanocomposite, yielding a homogeneous dispersion of the silver nanoparticles in the alanine matrix or flocs of silver nanoparticles segregated from the alanine crystals. The alanine crystalline orientation is modified according to the particle size of the silver nanoparticles. Concerning a mass percentage of silver below 0.1%, the nanocomposites are homogeneous, and there is no particle aggregation. As the mass percentage of silver is increased, the system becomes unstable, and there is particle flocculation with subsequent segregation of the alanine crystals. The nanocomposites have been analyzed by transmission electron microscopy (TEM), UV-Vis absorption spectroscopy, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy and they have been tested as radiation detectors by means of electron spin resonance (ESR) spectroscopy in order to detect the paramagnetic centers created by the radiation. In fact, the sensitivity of the radiation detectors is optimized in the case of systems containing small particles (30 nm) that are well dispersed in the alanine matrix. As the agglomeration increases, particle growth (up to 1.5 μm) and segregation diminish the sensitivity. In conclusion, nanostructured materials can be used for optimization of alanine sensitivity, by taking into account the influence of the particles size of the silver nanoparticles on the detection properties of the alanine radiation detectors, thus contributing to the construction of small-sized detectors.     

Tuned interactions of silver nanoparticles with ZSM-5 zeolite by adhesion-promoting poly(acrylic acid) deposited by electrospray ionization (ESI)

The electrospray ionization (ESI) method was used for deposition of thin films of poly(acrylic acid) (PAA) on Cu/ZSM-5 (5 wt.% Cu) and Ag–Cu/ZSM-5 (1 wt.% Ag and 4 wt.% Cu) composites. For comparative purposes, the ZSM-5 zeolite was synthesized under hydrothermal conditions and loaded with PAA under the same treating conditions as the composites. This method allowed the formation of uniform polymer films of controlled thickness on conductive substrates. The structural characteristics were characterized by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, atomic force microscopy and X-ray diffraction (XRD). The deposited PAA layer over ZSM-5 acts as a common dispersing and stabilizing agent through coordination-driven guest-templated polymer via interaction of Ag⁺ and Cu²⁺ with carboxylic acid groups, thus increasing and controlling the adhesion and the release of metallic species. A short exposure to light and temperature has reduced the metal ions to Cu⁰ and Ag⁰ metallic nanoparticles. The results of XRD analysis let suggest that the interaction of Cu and Ag with carboxylic groups of PAA inhibits the formation of large metallic silver particles. These samples were being studied for their potential as antibacterial agents toward the bacterial strains such as Staphylococcus pneumonia, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa as Gram positive and Gram negative bacteria, respectively. Aspergillus fumigatus and Candida albicans as Fungi were also evaluated. The Cu/ZSM-5 and Ag–Cu/ZSM-5 nanocomposites coated with a 10 nm thick PAA layer exhibit significant antibacterial activity.     

Preparation and characterization of cellulose/Ag nanocomposites

A simple, green, and efficient microwave‐assisted heating method was developed to synthesize the cellulose/Ag nanocomposites by reducing silver nitrate in aqueous solution. The structure of nanocomposites was analyzed with X‐ray diffraction and Fourier transform infrared, the results showed that nanosilver particles were synthesized successfully on the surface of cellulose and did not change the structure of cellulose obviously. The shape and average size of silver nanoparticles and its distribution on cellulose fiber surface were observed by scanning electron microscopy, and the results demonstrated that the silver nanoparticles had a good distribution on the surface of cellulose fiber and high dosage of polyvinyl pyrrolidone decreased the size of nanosilver particles. Atomic absorption spectroscopy was used to measure the silver content in the composites, it was found that the silver content was higher in composites obtained by microwave heating compared with oil bath heating. The effect of silver nanoparticles on the thermal stability of cellulose fiber was studied by thermogravimetric analysis and differential scanning calorimetry, and it revealed that the silver nanoparticles had no obvious influence on the thermal stability of cellulose. The excellent antimicrobial activity against both Escherichia coli (gram‐negative bacteria) and Staphylococcus aureus (gram‐positive bacteria) showed a potential application in medical and health care field. POLYM. COMPOS., 36:2220–2229, 2015. © 2014 Society of Plastics Engineers