Papers by Keyword: Silver Nitrate

Abstract: Commercially pure titanium and its alloys have been widely applied as implant materials with excellent long-term results and present benefits compared to other metal biomaterials because of the good mechanical strength and modulus of elasticity with values close to those of the bone. Titanium implants coated with hydroxyapatite give the metal a bioactive surface, which induces a direct connection between the implant and the bone tissue. As a consequence, the time for osseointegration, and hence the total treatment time, may be reduced. This paper aimed at studying the bactericidal effect of silver nitrate at 10 ppm and 100 ppm, incorporated in the layer on the surface of commercial titanium. The results showed efficiency in both osseointegration and bactericidal effect, confirmed by scanning electron microscopy, X-ray diffraction and corrosion tests. The bacterial culture tests, by means of the halo inhibition tests, indicate that the doping with AgNO₃ in concentrations 10 and 100 ppm did not present significant variation.

Abstract: We report our investigation of roles of polyvinyl alcohol (PVA) as a high-performance capping agent in synthesizing silver nanowires (AgNWs) using polyol method. For this purpose, we varied the concentration of silver nitrate (AgNO3), from 0.3 M to 1.0 M, and molar ratios of [PVA:AgNO3] from 2 to 6. The UV-vis spectra show the AgNWs growth optimally at a molar ratio of 4.5 with the absorbance peaks of 378 nm and 380 nm. Meanwhile, from XRD patterns, it was found that the crystal structure of the AgNWs can be identified as a face-centered cubic (fcc) with a lattice constant according to the spacing distance between the {111} planes of 4.087 Å. Finally, scanning electron microscopy (SEM) and transmission electron microscopy TEM images show the diameter and length of the AgNRs are 150 to 230 nm and 50 to 120 µm, respectively. These results show that the AgNWs synthesized using PVA having a long size.

Abstract: In this research work, a very simple, low cost eco-friendly method is presented for the synthesis of silver nanoparticles to be used in colorimetric optical sensors based on localized SPR (LSPR) measurement for gas ammonia. Silver nitrate salts are reduced using gaur gum which acts as a capping and reducing agent. Commonly used reducing agents such as trisodium citrate or sodium borohydride are replaced by a more environmental friendly natural polysaccharide. Nanocomposite films of ~ 1.5 μm thicknesses were fabricated using Gaur Gum and silver nanoparticles. The uniformity of nanoparticles size was measured by SEM and TEM, while face centred cubic structure of crystalline silver nanoparticles was characterized using the X-ray diffraction technique. The optical properties of the composite film were tested by UV-VIS Spectroscopy. The formation of Gaur Gum/silver nanocomposite films was confirmed using SEM images. Also the resistivity of nanocomposite thin film was measured which could be then used for gas sensing application.

Abstract: In this work, silver nanoparticles were synthesized using the precipitation method at room temperature. The size of the silver nanoparticle was analyzed using transmission electron microscope and found to be in the range of 20 to 40 nm. The multi-functional transparent film on glass substrate was prepared using silver nanoparticle solutions and 3-Glycidyloxypropyltrimethoxy silane (GLYMO) by dip coating method. Ultraviolet visible spectroscopy measurement shows low absorbance thus confirming high transparency level. The critical load obtained from the micro-scratch test showed an increase from 3000 mN to 3319 mN.

Abstract: onic conductivity and dielectric properties of starch based polymer electrolytes doped with silver nitrate (AgNO₃) at elevated temperatures were studied. The solid polymer electrolytes were prepared using the solution cast method. X-ray diffraction (XRD) analysis implied that the incorporation of 6 wt.% AgNO₃ increased the amorphous phase of the electrolyte. Temperature dependence conductivity plots showed that electrolyte containing 6 wt.% AgNO₃ obeyed Arrhenius rule with activation energy, E_a of 0.71 eV. The effect of temperature on the dielectric properties of the electrolyte was also studied in relation to the conductivity properties. The variation of dielectric loss with frequency was obtained from the power law exponent. Temperature dependence of the power law exponent concluded that the conduction mechanism of the 94 wt.% starch-6 wt.% AgNO₃ electrolyte followed the correlated barrier hopping (CBH) model.

Abstract: Flake silver powder has attracted tremendous interesting due to its specially electrical and optical properties. Chemical reduction method with the advantages of reaction conditions easily controlled and mass production is widely used to prepare flake silver particles. In order to more easily prepare flake silver particles, the generation mechanism of flake silver particles is studied by analyzing the impacts of reaction conditions, such as pH value, kinds of silver seeds, kind of surfactant and concentration of raw material. The results show that flake silver particles can be prepared through controlling reaction conditions. Some problems existing in the preparation of flake silver particles are put forward, and future research directions are also proposed.

Abstract: Abstract: This investigation develops a novel method for fabricating silver chloride films by the heterogeneous precipitation of sodium chloride from aqueous solution and supersaturated solid-state silver nitrate out of aqueous solution. The morphology of the bottom surface of the silver chloride film thus obtained comprises numerous porous stick structures. The top surface comprises equiaxed grains, and columnar grains are observed in the cross-section.

Abstract: Cotton fabric with excellent antibacterial properties was obtained by treated with polyamide-amine (PAMAM) dendrimers as a carrier and silver nitrate as an antibacterial agent. The antibacterial cotton fabrics were prepared by the methods of one-bath process and two-bath process. Antibacterial activity of cotton fabrics treated by two different methods was good, but the antibacterial durability of cotton fabric treated with two-bath process was better than that treated with one-bath process. After 50 washing cycles, cotton fabric treated with two-bath process still had good antibacterial property and its inhibitory rate to Gram-positive S. aureus and Gram-negative E. coli was over 99 %. It was found that the breaking strength retention of finished cotton fabrics was 85.83 % and the decrease of cotton fabrics’ whiteness index was about 15 %.

Abstract: The present study is concerned with the morphology, physical properties and biocidal activity of Al2O3-Ag nanopowders produced by two methods: thermal decomposition-reduction and the silver nitrate reduction. The innovative method of thermal decomposition-reduction has been described in our earlier publication and is protected by our patent application, whereas the silver nitrate reduction method is commonly used in industry at the present. The nano-powders produced by these two methods differ considerably from one another in terms of their morphology and physical properties. The proposed method of thermal decomposition-reduction gives Al2O3-Ag nano-powders which are not only much less agglomerated with the average agglomerate sizes below 1 µm, but also the average size of their particles is considerably smaller (below 60 nm). Moreover, their specific surface is larger (above 200 m2g-1) and they have good bactericidal and fungicidal properties.