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1.
A nanocomposite reservoir‐type hydrogel dressing of poly vinyl alcohol (PVA) was fabricated by a freeze–thaw method and loaded with silver‐nanoparticle‐coated chitosan wafers (Ag–CHWs). The Ag–CHWs were synthesized by a sonication technique with silver nitrate (AgNO3) and chitosan powder. Scanning electron microscopy images showed silver nanoparticles (AgNPs) with a size range of 10 ± 4 nm on the surface of the chitosan wafers, and the antibacterial efficacy (minimum inhibitory concentration) of the Ag–CHWs was measured against Pseudomonas aeruginosa (32 µg/mL), Staphylococcus aureus, (30 µg/mL) and Escherichia coli (32 µg/mL). The antimicrobial PVA hydrogel showed an improved tensile strength (~0.28 MPa) and gel content (~92%) in comparison with the blank hydrogels. Full‐thickness‐excision wound studies of the nanocomposite dressing on Wistar rats revealed enhanced wound contraction, improved inflammation response, re‐epithelization rate, neoangiogenesis, and granulation tissue formation in comparison to the control group. A flexible, biocompatible, nanocomposite reservoir dressing not only established the chitosan as a stabilizer but also proved the efficacious and safe utility of AgNPs toward chronic wound management. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43472.  相似文献   

2.
This work investigates the effect of the incorporation of zinc oxide (ZnO) nanoparticles within a poly(l -lactic acid) (PLLA) matrix as an approach to speed up the hydrolysis of PLLA film surfaces. Hydrolysis was done by immersing nanocomposite films having 1 wt % of ZnO in 0.25 M sodium hydroxide at 58 °C. This concentration has been selected as it provides the maximum changes of physicochemical properties of hosting PLLA matrix. The evolution of the thermal properties, ultraviolet–visible transparency, wettability, and morphology were monitored at different time points. The amount of carboxylic groups onto PLLA/ZnO surfaces was quantified according to Toludine Blue-O assay. Hydrolysis was mainly limited to film surfaces, which were grafted by carboxylic groups as a result of the random scission of PLLA ester linkages. The presence of such functional groups decreases the inherent surface hydrophobicity of PLLA at short hydrolysis times. On the contrary, long hydrolyses increase the hydrophobicity as a result of surface nanostructuring induced by the degradation of PLLA to water-soluble oligomers. Overall, ZnO nanoparticles enable shorter surface modification times and provide a quick approach for the modification on the polarity of polylactide surfaces. The potential of hydrolyzed films as antimicrobial materials was explored using Gram-negative Escherichia coli as a model. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47786.  相似文献   

3.
A layer of a polyethylene–silver nanoparticles composite was deposited on a five layer barrier film structure. Different methods were used for the nanocomposite layer deposition: laminating, casting, and spraying over the multilayer structure. For the casting and spraying methods, the silver nanoparticles were previously dispersed in the polymer solution, with the assistance of ultrasound energy. The effect of silver nanoparticles and deposition method on the barrier, mechanical, and optical properties of the multilayer films was evaluated. The efficiency of silver ion release from the PE‐Silver nanocomposite deposited on the multilayer films and their antimicrobial characteristics were investigated and discussed. The silver ion release and biocide effect of the multilayer films was found to be dependant on the silver nanoparticle content and on the deposition method used. The observed results could be helpful in the design of industrial films for packaging. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

4.
This work focuses the preparation of polymer‐silver nanocomposite (Ag‐Nc) dense free standing films and nonwoven fabric supported porous ultrafiltration membranes with improved membrane performance and long‐term antibiofouling properties. New polyacrylonitrle‐based Ag‐Ncs, poly(acrylonitrle‐co‐acrylic acid)‐silver (PAN‐co‐PAA‐Ag) containing 35 wt% of PAA and 0.35–0.65 wt% of Ag‐nanoparticles (Nps) were synthesized and used as additives for the fabrication of PAN‐based (PAN/PAN‐co‐PAA‐Ag) Ag‐Nc porous membranes and dense‐free standing films. The Ag‐Nps were homogeneously dispersed into the PAN‐co‐PAA random copolymer matrix. The prepared membranes (PAN/PAN‐co‐PAA‐Ag) showed combination of properties such as excellent antimicrobial activity towards both Gram Negative and Gram Positive bacteria (prevent biofilm formation), improved protein antifouling properties, and enhanced water flux when compared to neat PAN‐based membrane. The antimicrobial properties, hydrophilicity, and the water flux of various membranes follow the following order for the membranes PAN < PAN/PAN‐co‐PAA < PAN/PAN‐co‐PAA‐Ag. Extraneous addition of small amount of polyethylene glycol (PEG) during preparation of additive i.e. [PEG + PAN‐co‐PAA]‐Ag further improved the protein antifouling properties of the PAN‐based membranes (PAN/[PEG+PAN‐co‐PAA‐Ag]). The dispersed Ag‐Nps were stable on the surface of phase inverted membranes for long period of time and PAN/PAN‐co‐PAA‐Ag membranes are therefore suitable for long‐term water treatment under bacterial environment. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers  相似文献   

5.
Silver nanoparticles were deposited on the surface of the external polyamide 6 (PA6) layer of a multilayer film, by spraying and ultrasound‐assisted methods. The effect of silver nanoparticles content and deposition method on the mechanical and optical properties of the multilayered films as well as the efficiency of silver ion release and their fungicidal characteristics were evaluated. Itaconic (IA) and Maleic anhydride (MA) were used as adhesion promoter agents for preventing the agglomeration of the silver nanoparticles and for improving the adhesion to the PA6 polymer surface. With IA, a homogeneous distribution of silver nanoparticles on the PA6 surface was achieved. The silver ion release and biocide effect of the multilayered films was found to be dependent on the anhydride type and on the deposition method used. The multilayer films with a layer of PA6‐silver nanocomposite demonstrated good fungicidal activity, specifically against fungus Aspergillius niger. The observed results could be applied in the design of industrial films for packaging. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

6.
Hydrogel silver nanocomposites are found to be excellent materials for antibacterial applications. To enhance their applicability novel hydrogel‐silver nanoparticle‐curcumin composites have been developed. For developing, these composites, the hydrogel matrices are synthesized first by polymerizing acrylamide in the presence of poly(vinyl sulfonic acid sodium salt) and a trifunctional crosslinker (2,4,6‐triallyloxy 1,3,5‐triazine, TA) using redox initiating system (ammonium persulphate/TMEDA). Silver nanoparticles are generated throughout the hydrogel networks using in situ method by incorporating the silver ions and subsequent reduction with sodium borohydride. Curcumin loading into hydrogel‐silver nanoparticles composite is achieved by diffusion mechanism. A series of hydrogel‐silver nanoparticle‐curcumin composites are developed and are characterized by using Fourier transform infrared (FTIR) and UV–visible (UV–vis) spectroscopy, X‐ray diffraction, thermal analyses, as well as scanning and transmission electron microscopic (SEM/TEM) methods. An interesting arrangement of silver nanoparticles i.e., a shining sun shape (ball) (~ 5 nm) with apparent smaller grown nanoparticles (~ 1 nm) is observed by TEM. The curcumin loading and release characteristics are performed for various hydrogel composite systems. A comparative antimicrobial study is performed for hydrogel‐silver nanocomposites and hydrogel‐silver nanoparticle‐curcumin composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

7.
This article reports the temperature‐sensitive, green tea (GT)‐based silver‐nanocomposite hydrogels for bacterial growth inactivation. The temperature‐sensitive hydrogels were prepared via free‐radical polymerization using temperature‐sensitive N‐isopropylacrylamide (NIPAM) monomer with GT as the hydrogel matrix. The nanocomposite hydrogels were encapsulated with silver ions via swelling method, which was later reduced to silver nanoparticles using Azadirachta indica leaf extract. The temperature‐sensitive silver nanocomposite hydrogels were analyzed by using Fourier transforms infrared, UV–visible spectroscopy, differential scanning calorimetry–thermogravimetric analysis, X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. The prepared hydrogels exhibited higher phase volume transition temperature than the NIPAM. The inhibition zone study of the inactivation of bacteria on the developed hydrogels was carried out against Gram negative (Escherichia coli) and Gram positive (Staphylococcus aureus), which revealed that the prepared hydrogels are helpful for the inactivation of these bacteria due to the high stabilization of antibacterial properties of the silver nanoparticles. The developed hydrogels are promising for biomedical applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45739.  相似文献   

8.
Poly(L ‐lactic acid) (PLLA), poly(ε‐caprolactone) (PCL), and their films without or blended with 50 wt% poly(ethylene glycol) (PEG) were prepared by solution casting. Porous films were obtained by water‐extraction of PEG from solution‐cast phase‐separated PLLA‐blend‐PCL‐blend‐PEG films. The effects of PLLA/PCL ratio on the morphology of the porous films and the effects of PLLA/PCL ratio and pores on the physical properties and biodegradability of the films were investigated. The pore size of the blend films decreased with increasing PLLA/PCL ratio. Polymer blending and pore formation gave biodegradable PLLA‐blend‐PCL materials with a wide variety of tensile properties with Young's modulus in the range of 0.07–1.4 GPa and elongation at break in the range 3–380%. Pore formation markedly increased the PLLA crystallinity of porous films, except for low PLLA/PCL ratio. Polymer blending as well as pore formation enhanced the enzymatic degradation of biodegradable polyester blends. Copyright © 2006 Society of Chemical Industry  相似文献   

9.
X‐Ray diffraction and X‐ray photoelectron spectroscopy studies, applied on some silicone‐silver nanocomposites, revealed the influence of the solvent used in preparation on the morphology of the resulted materials. It has been emphasized that dimethylformamide solvent favors the formation of silver nanoparticles and their migration at the surface, while water solvent favors the formation of a homogeneous composite with small silver nanoparticles. The places occupied by Ag nanoparticles (some prevent their oxidation and others that favor the oxidation process) are dependent on the mixture used in sol‐gel technique and have influence on the nanocomposite electrical conductivity. The temperature dependence of the electrical conductivity is investigated. A linear relationship between the pre‐exponential factor (σ0) and activation energy (Ea) was observed, in the high temperature range (T > 315 K), for all the samples, indicating that the conductivity data obey Meyer‐Neldel rule. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers  相似文献   

10.
Novel bioactive and optically active poly(N‐acryloyl‐L ‐phenylalanine) (PAPA) was synthesized by atom transfer radical polymerization. PAPA‐silver (Ag) nanocomposites have been successfully prepared via in situ reducing Ag+ ions anchored in the polymer chain using hydrazine hydrate as reducing agent in an aqueous medium. By controlling of the amount of Ag+ ions introduced, we have produced an organic/inorganic nanocomposite containing Ag nanoparticles with well controlled size. Nanocomposites were characterized by X‐ray diffraction (XRD), UV–Vis spectrophotometry, transmission electron microscopy, and Fourier transform infrared. XRD pattern showed presence of Ag nanoparticles. The PAPA/Ag nanocomposites with 1 : 10 silver nitrate (AgNO3) : PAPA ratio revealed the presence of well‐dispersed Ag nanoparticles in the polymer matrix. All of these Ag nanoparticles formed are spherical and more than 80% of them are in the range of 15–25 nm. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

11.
Self‐segregating hyperbranched polymer (HBP) additives have been utilized to concentrate silver nanoparticles (AgNPs) at the air interface of polyurethane films. The limited spontaneous surface migration of the AgNPs was enhanced through the addition of appropriately functionalized HBPs. Both amine and thiol terminated additives were employed to allow interaction of the HBP with the nanoparticles. Both types of additives increased surface concentration of silver modestly, though the thiol‐terminated HBPs demonstrated nearly a seven‐fold enhancement of surface migration. It was also found that wholly‐aliphatic HBPs demonstrated only slightly reduced ability to bias AgNP concentration as compared to HBPs functionalized with perfluorinated chains. In addition, films containing 1% total silver concentration were tested for antimicrobial activity using the ASTM‐E 2180 protocol. Significant reduction of the microorganisms was observed for all samples, 6‐log reduction was achieved for the gram‐negative bacteria P. aeruginosa, the gram‐positive bacteria S. aureus, and the fungi C. albicans. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

12.
Novel nanocomposite films of chitosan/phosphoramide/Ag NPs were prepared containing 1–5% of silver nanoparticles. The Ag NPs were synthesized according to the citrate reduction method. The XRD and SEM analysis of Ag NPs, chitosan (CS), phosphoramide (Ph), CS/Ph, CS/Ag NPs films and the nanocomposite films 1–5 containing CS/Ph/1–5% Ag NPs were investigated. The in vitro antibacterial activities were evaluated against four bacteria including two Gram‐positive Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus) and two Gram‐negative Escherchia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) bacteria. Results revealed greater antibacterial effects of the films against Gram‐positive bacteria. Also, nanocomposite films containing higher percent of Ag NPs showed more antibacterial activities. POLYM. COMPOS. 36:454–466, 2015. © 2014 Society of Plastics Engineers  相似文献   

13.
Silver nanoparticles were produced inside a poly(N‐vinyl‐2‐pyrrolidone) hydrogel (PVP) by an innovative method based on the electrochemical reduction of Ag+ ions within the swollen PVP hydrogel. UV‐visible spectroscopy showed the highest value of the absorbance intensity and the lowest values of the wavelength of the absorbance maximum and the full width at the half‐maximum absorbance for the Ag/PVP nanocomposite obtained at 200 V during 4 min. Cyclic voltammetry results suggested an adequate entrapment of the silver nanoparticles. The mechanical properties under bioreactor conditions of the Ag/PVP nanocomposite suggested the possibility of wound dressing application. Silver release from Ag/PVP nanocomposites was confirmed under static conditions as well as by their antimicrobial activity against Staphylococcus aureus. POLYM. COMPOS., 35:217–226, 2014. © 2013 Society of Plastics Engineers  相似文献   

14.
In this scientific work, a novel class of antimicrobial nanocomposite hydrogels were designed and synthesized by chemical and environmentally bioprocess using Kolliphor, acrylamide, and mint leafs in order to achieve antiseptic property for wound applications. In the bioprocess approach, silver nitrate and gold chloride were nucleated with mint leafs in order to obtain effective free individual nano‐inorganic compounds to provide superior antibacterial assets. The formations of dual inorganic nanoparticles were confirmed by transmission electron microscopy, which indicated the size of nanoparticles in the range of approximately 3 ± 2 nm and without agglomeration. The formations of biomaterials were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopic–energy dispersive spectrometric studies and their swelling properties were determined. Furthermore, the pure hydrogel and the dual inorganic nanocomposite hydrogels developed were tested for antibacterial activities. When compared with the neat hydrogel, the nanocomposite hydrogels significantly improved their anti‐bacterial activities on Bacillus bacterium. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42781.  相似文献   

15.
Silver nanoparticle‐reinforced thermoplastic polyurethane (PU/AgNP) nanocomposite foams were prepared using in situ polymerization techniques in accordance with DOW chemicals’ industrial standards. The foams exhibited improved mechanical performance, induced antimicrobial properties, and intact stability when subjected to a thermal degradation treatment. Scanning electron microscopy (SEM) indicated a homogeneous dispersion of the silver nanoparticle (AgNP) within the polymeric matrix at low filler loadings and a cluster formation at higher loadings. SEM also indicated the agglomeration of the silver nanofiller particles as a result of the thermal degradation treatment, which caused them to lose their nanoscopic characteristics and act as ordinary silver metal. Molecular modeling techniques were used to explain these observations and confirmed the higher repulsive interactions between the polymer chains and the silver nanoparticles with the increase in the nanofiller content. Stress relaxation of the nanocomposites showed optimum mechanical performance and lowest hysteresis for the 0.1% AgNP nanocomposites due to the confinement of the PU chains between the large number of the nanoparticles. Incubation with 0.1% foam inhibited the growth of Klebseilla spp. and Escherichia coli and to some extent Staphylococcus spp. This is very interesting as the same nanocomposite loaded with 0.1% AgNp has also shown the best mechanical performance highlighting the strong action of this “unclustered” low concentration on both the material and biomedical sides. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43125.  相似文献   

16.
Silver (Ag) nanoparticles are known to hold an important place in nanotechnology, and studies herein present the preparation and characterization of Ag metallic nanoparticles bearing antibacterial properties. In situ polymerization was used to prepare the conductive polymer polyaniline (PANI) and polyaniline/silver (PANI/Ag) nanocomposites. Increases in electrical conductivities of the nanocomposite films were observed compared to neat PANI, whereby these increases may be a result of the Ag doping effect or its complex formation. Spectroscopic techniques, such as, UV–Vis, FTIR, and photoluminescence were used for the characterizations of PANI and PANI/Ag nanocomposites. UV–Vis and FTIR data showed the quinoid units along the polymer chain being affected, such that strong interactions between Ag nanoparticles and quinoidal sites of PANI were presumed. The PANI/Ag nanocomposites showed higher photoluminescence intensities than neat PANI. TGA analyzes were used to determine weight losses and thermostabilities of PANI and PANI/Ag nanocomposites. Scanning electron microscopy was used for morphological evaluations of the nanoparticles and films, where the micrographs revealed that Ag nanoparticles were well dispersed and isolated in nanocomposite films. The presence and distribution of the Ag nanoparticles in PANI film matrix were analyzed by EDX. Antimicrobial properties of the nanocomposite films obtained were also explored. POLYM. ENG. SCI., 59:E182–E194, 2019. © 2018 Society of Plastics Engineers  相似文献   

17.
Poly(L ‐lactide), that is, poly(L ‐lactic acid) (PLLA), poly(ε‐caprolactone) (PCL), and their blend (50/50) films containing different amounts of poly(L ‐lactide‐co‐ε‐caprolactone) (PLLA‐CL), were prepared by solution casting. The effects of added PLLA‐CL on the enzymatic hydrolysis of the films were investigated in the presence of proteinase K and Rhizopus arrhizus lipase by use of gravimetry. The addition of PLLA‐CL decreased the proteinase K–catalyzed hydrolyzabilities of the PLLA and PLLA/PCL (50/50) films as well as the Rhizopus arrhizus lipase‐catalyzed hydrolyzability of the PCL and PLLA/PCL (50/50) films. The decreased enzymatic hydrolyzabilities of the PLLA and PCL films upon addition of PLLA‐CL are attributable to the fact that the PLLA‐CL is miscible with PLLA and PCL and the dissolved PLLA‐CL must disturb the adsorption and/or scission processes of the enzymes. In addition to this effect, the decreased enzymatic hydrolyzabilities of the PLLA/PCL (50/50) films upon addition of PLLA‐CL can be explained by the enhanced compatibility between the PLLA‐rich and PCL‐rich phases arising from the dissolved PLLA‐CL. These effects result in decreased hydrolyzable interfacial area for PLLA/PCL films. The decrement in proteinase K–catalyzed hydrolyzability of the PLLA film upon addition of PLLA‐CL, which is miscible with PLLA, was in marked contrast with the enhanced proteinase K–catalyzed hydrolyzability of the PLLA film upon addition of PCL, which is immiscible with PLLA. This confirms that the miscibility of the second polymer is crucial to determine the proteinase K–catalyzed hydrolyzabilities of the PLLA‐based blend films. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 412–419, 2003  相似文献   

18.
Octylamine‐coated silver nanoparticles with an average size of 10 nm were synthesized and added to the AZO powder as fillers to increase the density of the sintered target. The resulting Ag–AZO nanocomposite powder was formed into compacts by a uniaxial pressing process. It was found that the addition of octylamine‐ coated silver nanoparticles can increase the density of AZO powder compacts by ~ 4% after sintering. The optimum content of silver addition is about 0.13 wt%. It is suggested that the melted silver fills the void space between agglomerate pores and enhances the interconnection between nanocrystalline AZO powders. The films deposited using the here‐synthesized Ag–AZO target showed lower resistivity and high carrier concentration compared with the one using AZO target.  相似文献   

19.
Blended films of poly(L ‐lactide) [ie poly(L ‐lactic acid)] (PLLA) and poly(?‐caprolactone) (PCL) without or mixed with 10 wt% poly(L ‐lactide‐co‐?‐caprolactone) (PLLA‐CL) were prepared by solution‐casting. The effects of PLLA‐CL on the morphology, phase structure, crystallization, and mechanical properties of films have been investigated using polarization optical microscopy, scanning electron microscopy, differential scanning calorimetry and tensile testing. Addition of PLLA‐CL decreased number densities of spherulites in PLLA and PCL films, and improved the observability of spherulites and the smoothness of cross‐section of the PLLA/PCL blend film. The melting temperatures (Tm) of PLLA and PCL in the films remained unchanged upon addition of PLLA‐CL, while the crystallinities of PLLA and PCL increased at PLLA contents [XPLLA = weight of PLLA/(weight of PLLA and PCL)] of 0.4–0.7 and at most of the XPLLA values, respectively. The addition of PLLA‐CL improved the tensile strength and the Young modulus of the films at XPLLA of 0.5–0.8 and of 0–0.1 and 0.5–0.8, respectively, and the elongation at break of the films at all the XPLLA values. These findings strongly suggest that PLLA‐CL was miscible with PLLA and PCL, and that the dissolved PLLA‐CL in PLLA‐rich and PCL‐rich phases increased the compatibility between these two phases. © 2003 Society of Chemical Industry  相似文献   

20.
A series of polypropylene carbonate (PPC)/ZnO nanocomposite films with different ZnO contents were prepared via a solution blending method. The morphological structures, thermal properties, oxygen permeability, water sorption, and antibacterial properties of the films were investigated as a function of ZnO concentration. While all of the composite films with less than 5 wt % ZnO exhibited good dispersion of ZnO in the PPC matrix, FTIR and SEM results revealed that solution blending did not lead to a strong interaction between PPC and unmodified ZnO. As such, poor dispersion was induced in the composite films with a high ZnO content. By incorporating inorganic ZnO filler nanoparticles, the diffusion coefficient, water uptake in equilibrium, and oxygen permeability decreased as the content of ZnO increased. The PPC/ZnO nanocomposite films also displayed a good inhibitory effect on the growth of bacteria in the antimicrobial analysis. The enhancement in the physical properties achieved by incorporating ZnO is advantageous in packaging applications, where antimicrobial and environmental‐friendly properties, as well as good water and oxygen barrier characteristics are required. Furthermore, UV light below ~ 350 nm can be efficiently absorbed by incorporating ZnO nanoparticles into a PPC matrix. ZnO nanoparticles can also improve the weatherability of a PPC film. In future research, the compatibility and dispersion of the PPC matrix polymer and the inorganic ZnO filler nanoparticles should be increased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.  相似文献   

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