Nanoparticle silver oxide

Ag/Si02 composites prepared by the one-step method and two-step methods were characterized by TGA/DTA, FTIR, XRD, and TEM. The results showed that Ag or silver oxide nanoparticles in 20 to30 nm were dispersed on the surface of the carrier Si02. The calcination temperature and prepared method affect the crystal phase of the functional component. 

It is natural to expect that in the first case localization of silver nanoparticles-labeled protein A is caused by presence of antibodies on the surface, which results in silver oxidation current signal. In the second case, localization does not happen as antibodies are not present in the solution. 

It can be concluded that silver-oxidation current can be used as a signal-generating reaction for measuring the given antibody concentration in the test sample and the use of protein A labeled with silver nanoparticles is valid. 

Our study h as demonstrated that formation of silver nanoparticles in "Ag -Ge02" system proceeds through the decomposition of silver germanate formed after the earlier steps of film heating. That mechanism provides a considerable stability of Ag nanoparticles to oxidation on heating up to 900°C, suggesting that the silver particles are encapsulated by the matrix. 

The crystallinity of hydrogel/silver nanocomposite could be established by diffraction studies. The formation of silver nanoparticle confirm by International Centre of Diffraction Data, ICDD, library of silver. The diffraction peaks for hydrogel/silver nanocomposites found at 26 value of 38.1°, 44.26°, 64.50°, and 77.42° are attributed due to (111], (200], (220], and (311] planes of FCC, respectively (Bajpai et al., 2013 Daniel et al., 1996 Murali Mohan et al., 2010]. Pure hydrogel failed to show any peak in the XRD indicating its amorphous nature. In order to check whether the silver nanoparticles were oxidized to silver oxide, the XRD pattern of composite after storing it for three months was compared with original one. If it has the same pattern as that of fresh hydrogel/silver nanocomposite, this indicates its stability at ambient condition. 

X. Zhou, Y. Lu, L.-L. Zhai, Y. Zhao, Q. Liu, W.-Y. Sun, RSC Adv. 2013, 3, 1732-1734. Propargylamines formed from three-component coupling reactions catalyzed by silver oxide nanoparticles. 

Boron nitride nanocages with silver nanoparticles encapsulated in them have been synthesized by Oku et al." Reaction of urea and boric acid in the presence of silver nitrate produced BN matrices at 700°C. The ingredients were previously dissolved in deionized water and dried consequently to produce a homogenous mixture and annealed separately at 300°C and 700°C. The presence of silver nanoparticles and sometimes silver oxide nanoparticles were detected under TEM (Figure 20.15a) and x-ray diffraction studies. A similar methodology has been developed by Xing et al. in their preparation of zinc oxide- and titanium oxide-encapsulated BN nanocages." ... 

As already mentioned, PVA is a water soluble polymer used in applications such as packaging films where water solubility is desired. It is the most readily biodegradable of the vinyl polymers, which makes it a potentially useful material in biomedical, agricultural, and water treatment areas, for example, as a flocculant, or scavenger of metal ions. Moreover, due to its water solubility, PVA can also be used as a model for particle dispersion in aqueous suspensions, especially those from CNWs and some clays. As a consequence, PVA has been largely used to produce nanocomposites with clays, cellulose, and chitin whiskers, silver nanoparticles, graphite oxide, and carbon nanotubes. 

Park K, Park E-J, Chun IK et al (201 lb) Bioavailability and toxicokinetics of citrate-coated silver nanoparticles in rats. Arch Pharmacol Res 34(1) 153-158 Piao Ml, Kang KA, Lee IK et al (2011) Silver nanoparticles induce oxidative cell damage in human liver cells through inhibition of reduced glutathione and induction of mitoehondria-involved apoptosis. Toxicol Lett 201(1) 92-100 Podsiadlo P, Kaushik AK, Arruda EM et al (2007) Ultrastrong and stiff layered polymer nanocomposites. Science 318(5847) 80-83... 

H., Bilmes, SA., Fainstein, A., and Soler-Illia, G.J. (2014) Silver nanoparticle mesoporous oxide nanocomposite thin films a platform for spatially homogeneous SERS-active substrates with enhanced stabiUty. ACS AppL Mater. Interfaces, 6, 5263-5272. 

In this chapter, photoelectrochemical control of size and color of silver nanoparticles, i.e., multicolor photo-chromism [1], is described. Silver nanoparticles are deposited on UV-irradiated Ti02 by photocatal5dic means [2]. Size of the nanoparticles can be roughly controlled in the photocatalytic deposition process. However, it is rather important that this method provides nanoparticles with broadly distributed sizes. The deposited silver nanoparticles are able to be dissolved partially and reduced in size by plasmon-induced photoelectrochemical oxidation in the presence of an appropriate electron acceptor such as oxygen. If a monochromatic visible light is used, only the particles that are resonant with the light are dissolved. That is, size-selective dissolution is possible [3]. This is the principle of the multicolor photochromism. 

The present technique enables light-induced redox reaction UV light-induced oxidative dissolution and visible light-induced reductive deposition of silver nanoparticles. Reversible control of the particle size is therefore possible in principle. The reversible redox process can be applied to surface patterning and a photoelectrochemical actuator, besides the multicolor photochromism. 

Cu2+ and Hg2+ are perhaps the most obvious targets for reaction-based signaling systems. However, this approach has also been realized for monovalent Ag+. Here, again a rhodamine derivative (rhodamine B spirolactam 48, Fig. 18) allows the highly selective detection of Ag+ with a detection limit of 14 ppb in water containing 20% ethanol. Silver nanoparticles, a topical analyte today, can also be detected, after oxidation of the particles with H2O2/H3PO4 [141]. The selectivity was tested with Ca2+, Ba2+, Mg2+, Cr2+, Mn2+, Fe3+, Co2+, Ni2+, Cu+, Cu2+, Zn2+, Pd2+, Cd2+, Hg+, and Hg2+ and no interference was found. 

Point of Use Wastewater Treatment Using Agglomerated Nanoparticles of Titanium (IV) oxide and Blotter Paper Impregnated with Silver Nanoparticles in Colum Mode... 

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