MMT-supported Ag nanoparticles for chitosan nanocomposites: Structural properties and antibacterial activity (original) (raw)
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Journal of Advance Nanobiotechnology, 2018
Silver nanostructures as an effective antibacterial materials were synthesized via three various hydrothermal, sono-chemical and microwave methods using water as a green solvent. Then Chitosan-Ag polymer based nanocomposites were made by a fast chemical procedure. The influence of power, temperature and time on the morphology and particle size of the products was investigated. Scanning electron microscopy (SEM) approved that mono-disperse nanoparticles were achieved using all three procedures. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy confirmed preparation of pure products. The antibacterial behaviour of Chitosan-Ag nanocomposites was evaluated using degradation of E coli bacteria. The results show a nanocomposite with applicable antibacterial performance in burn wounds.
Advances in Materials Science and Engineering, 2013
The aim of this study is to investigate the antibacterial properties and characterization of chitosan-silver nanoparticle composite materials. Chitosan-silver nanoparticle composite material was synthesized by adding AgNO3and NaOH solutions to chitosan solution at 95°C. Different concentrations (0,02 M, 0,04 M, and 0,06 M) of AgNO3were used for synthesis. Chitosan-silver nanoparticle composite materials were characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet (UV) spectrophotometer, and Fourier transform infrared (FTIR) spectrometer techniques.Escherichia coli,Acinetobacter baumannii,Staphylococcus aureus,Enterococcus faecalis,Pseudomonas aeruginosa, andStreptococcus pneumoniaewere used to test the bactericidal efficiency of synthesized chitosan-Ag nanoparticle composite materials. The biological activity was determined by the minimum bacterial concentration (MBC) of the materials. Antibacterial effect of chitosan-silver nanoparticle materia...
International Journal of Nanomedicine, 2010
Problem statement: Silver/Montmorillonite/Chitosan Bionanocomposites (Ag/MMT/Cts BNCs) have been synthesized by UV-irradiation reduction method in the absence of any reducing agent or heat treatment which is used to antibacterial application and medical devices. Approach: MMT, Chitosan and AgNO 3 were used as a solid support, stabilizer and silver precursor, respectively. The properties of Ag/MMT/Cts BNCs were studied as a function of UV-irradiation times. The crystalline structure, d-spacing of interlayer of MMT, the size distributions and surface plasmon resonance of synthesized silver nanoparticles (Ag-NPs) were characterized using Powder X-Ray Diffraction (PXRD), Transmission Electron Microscopy (TEM) and UV-vis spectroscopy. The functional groups of prepared BNCs were also determined by Fourier Transform Infrared (FT-IR). Results: The results obtained from UV-vis spectroscopy of synthesized Ag-NPs showed that the intensity of the maximum wavelength of the plasmon peaks were increased with the increasing in the UV-irradiation times. Results from UV-visible spectroscopy and Transmission Electron Microscopy (TEM) microphotographs show that particles size of Ag-NPs decrease with the increase of UV-irradiation time. Conclusion: UV-irradiation disintegrated the Ag-NPs into smaller size until a relatively stable size and size distribution were achieved. Ag/MMT/Cts BNCs could be suitable to antimicrobial applications and medical devices.
European Polymer Journal
n the present work chitosan-silver (CS/Ag) nanocomposites, either in the form of nanoparticles (AgNP) or as ionic dendritic structures (Ag+), are synthesized by a simple and environmentally friendly in situ chemical reduction process. The antibacterial activity of the resulting nanocomposites in the form of films is studied against two bacteria, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The relationship between electrical, structural and antibacterial properties of CS/AgNP and CS/Ag+ nanocomposites are studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction, and UV-Vis, impedance, infrared and X-ray photoelectron spectroscopies. The results demonstrate that in contrast to CS/Ag+ ion films, the CS/AgNP composites films (average particle size less than 10 nm) showed a significantly higher antibacterial potency. The collective action of AgNP and Ag+ ions facilitate the enhancement and synergetic antibacteria...
Synthesis and characterization of silver/clay/chitosan bionanocomposites by UV-irradiation method
Am J Appl Sci, 2009
In this study, we report an effective process for preparing silver nanoparticles (Ag NPs) by using Green reduction method of AgNO 3 in interlamellar space of Montmorillonite/Starch Bionanocomposites (MMT/Stc BNCs) suspension with moderate temperature. In here MMT, Starch, ȕ-D-glucose and AgNO 3 were used as a solid support, stabilizer, green reducing agent and silver precursor, respectively. Bionanocomposites material based on MMT, starch and silver nanoparticles (Ag/MMT/Stc BNCs) were prepared by adding starch and silver nitrate respectively into montmorillonite (MMT) dispersions in double distill water solution. The crystalline structure, d-spacing of interlayer of MMT, the size distributions, surface Plasmon resonance and functional groups of synthesized Ag NPs in the MMT/Stc BNCs were characterized using Powder X-Ray Diffraction (PXRD), Transmission Electron Microscopy (TEM), UV-visible spectroscopy and Fourier Transform Infrared Spectroscopy (FT-IR). The results obtained from TEM showed that the Ag NPs prepared in the extra surface of MMT layers have larger than Ag NPs intercalated between MMT layers, the particle size of nanoparticles synthesized by this processes were from 9 to 39 nm. Powder X-Ray Diffraction analysis showed that the synthesized Ag NPs crystallized in face centered cubic (fcc) symmetry. With gentle heating, this system is a mild, renewable, inexpensive, and nontoxic reducing agent. The synthesized bionanocomposites are very stable in aqueous solution over a long period of time (i.e., 3 months) without any sign of precipitation. Silver nanoparticles in MMT/Stc suspension could be suitable to use various medical applications. Since MMT is viewed as ecologically and environmentally inert material and used for biological application such as cosmetics and pharmaceutical usage.
Factors Affecting the Antibacterial Activity of Chitosan-Silver Nanocomposite
IET Nanobiotechnology, 2017
This study provides the optimum preparation parameters of chitosan-silver nanoparticles composite (CSNC) with promising antibacterial activity against the most common bacterial infections found on burn wounds. CSNC was synthesised by simple green chemical reduction method with different preparation factors. Chitosan was used to reduce silver nitrate and stabilise silver nanoparticles in the medium. For this reason, spectroscopic and microscopic techniques as, ultraviolet-visible Fourier transform infrared spectroscopy and transmission electron microscopy were used in the study of the molecular and morphological properties of the resultant composites. Furthermore, the composite was assessed in terms of Ag-ions release by AAS and its efficacy as antibacterial material. As a result, CSNC showed stronger antibacterial effect than its individual components (chitosan and silver nitrate solutions) towards Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria. CSNC prepared in this study showed highest inhibition percentage of bacterial growth up to 96% at concentration of 220 μg/ml.
Synthesis of Chitosan-silver nanocomposites and their antibacterial activity
International Journal of Scientific and Engineering Research
The present study explores the in situ fabrication of chitosan-silver nanocomposites in view of their increasing applications as antimicrobial packaging, wound dressing and antibacterial materials. Chitosan/Silver nanocomposites were prepared by embedding of silver nanoparticles in chitosan polymer. Synthesis of nanocomposites was confirmed by Fourier Transform Infrared (FTIR) spectroscopy, X-Ray Diffraction (XRD) analysis and Differential Scanning Calorimetry (DSC) etc. In addition, the formed nanocomposites have an average particle size of ~10-15 nm as observed by Transmission Electron Microscopy (TEM). Their antibacterial activity was assessed by zone of inhibition method against Staphylococcus aureus MTCC 1809, Pseudomonas aeruginosa MTCC 424 and Salmonella entrica MTCC 1253 in vitro.
Comparative Studies of Chitosan-Silver Nanocomposites from Commercial and Biowaste Sources
Nanochemistry Research, 2023
In this work, silver nanoparticles/chitosan nanocomposites were prepared for possible industrial and biomedical applications. Chemical reduction of silver nitrate salt produced silver nanoparticles (AgNPs). Low molecular weight chitosan (LMWCS) which connotes artificial chitosan (ArCS) was obtained, and biodegradable chitosan was extracted from snail shells using standard procedures. Sodium tripolyphosphate (TPP) was used to produce chitosan nanoparticles (snail shell nanochitosan (ScCSNPs) and artificial nanochitosan (ArCSNPs)) from extracted chitosan and LMWCS. AgNPs-CSNPs were produced by incorporating AgNPs into CSNPs as antimicrobial agents. Characterization of the chitosan doped silver nanoparticles was conducted using scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD). The morphological properties of nanochitosan (ScCSNPs and ArCSNPs) and AgNPs-nanochitosan (ScCSNPs-AgNPs and ArCSNPs-AgNPs) indicated porosity and agglomeration, while functional groups -OH, -NH, and C-H were revealed. The presence of AgNPs in the polymeric matrix of nanochitosan was confirmed by a shift in some of the adsorption bands.
XRD and DSC results revealed that the nanochitosan is crystalline, and they also confirmed the presence of AgNPs in the chitosan polymeric matrix. The study established that chitosan extracted from snail shells, which contributeo environmental pollution, could be a good source for the preparation of nanocomposite materials, which are useful in a variety of industrial and biomedical applications.
Purpose: To study the effect of chitosan molecular weight on the physicochemical and antibacterial properties of silver-chitosan nanoparticles. Methods: A series of silver-chitosan nanoparticles of different sizes were produced using various molecular weight (MW) grades of chitosan by an aqueous chemical reduction method. The nanoparticles were characterized by ultraviolet-visible absorption spectroscopy (UV-Vis), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), dynamic light scattering (DLS) and laser Doppler electrophoresis (LDE). The antibacterial properties of the nanoparticles were also evaluated by agar diffusion method. Results: The size of the silver-chitosan nanoparticles, ranging from 21.9 to 175.3 nm, was influenced by chitosan MW as well as by other process conditions. Although, the nanoparticles were not stable in liquid form, they however showed good stability in the solid state due to their low zeta potential. SEM images indicate that the nanoparticles were spherical. The antibacterial activity of the nanoparticles against Staphylococcus aureus increased with decrease in particle size owing to increase in surface area. The smallest particle size (21.9 nm) was obtained by using high chitosan MW at 4 °C and a stirring speed of 800 rpm. Conclusion: Chitosan is an effective agent for the preparation of silver nanoparticles. The size of the nanoparticles can be modulated by varying both chitosan MW and process conditions such as temperature and stirring speed.