scholarly journals Silver/poly(N-vinyl-2-pyrrolidone) nanocomposites obtained by the electrochemical synthesis

2011 ◽  
Vol 65 (6) ◽  
pp. 687-696 ◽  
Author(s):  
Zeljka Jovanovic ◽  
Aleksandra Radosavljevic ◽  
Zorica Kacarevic-Popovic ◽  
Vesna Miskovic-Stankovic
Keyword(s):  
Applied Voltage ◽  
Ag Nanoparticles ◽  
Silver Ions ◽  
Mie Scattering ◽  
Visible Spectroscopy ◽  
Vis Spectroscopy ◽  
Theoretical Predictions ◽  
Implementation Time ◽  
Uv Visible

Silver/poly(N-vinyl-2-pyrrolidone) (Ag/PVP) nanocomposites were obtained by electrochemical reduction of Ag+ ions at a constant voltage, by the in situ synthesis of silver nanoparticles inside poly(N-vinyl-2-pyrrolidone) matrix, previously crosslinked by ?-irradiation. Optimal values of synthesis parameters were investigated: the composition of the solution for swelling of PVP hydrogel, implementation time and applied voltage. Ag/PVP nanocomposites were characterized by UV-visible spectroscopy, and IR spectroscopy. UV-visible spectroscopy results shown that the reduction of silver ions was more efficient when the more conductive solution for swelling of PVP hydrogel was used, i.e. the solution containing 3.9 mM AgNO3 with 0.1 M KNO3. Also, it was shown that the concentration of the reduced silver increases with the increase in implementation time and applied voltage, up to the values of 4 min, and 200 V, respectively. The Ag nanoparticle size was estimated to be 25 nm, by comparison of the experimental results of UV-vis spectroscopy with the theoretical predictions obtained by the calculations in ?MiePlot v.3.4? computer program, having the algorithm based on Mie scattering from a sphere. The results of FTIR spectroscopy have shown that Ag nanoparticles are mainly bonded to PVP by coordination bondages between Ag nanoparticles and N from the pyrrolidone ring of PVP.

Biocompatibility of Silver Nano Bio-conjugates from Vitis vinifera Seeds and its Major Component Resveratrol

2016 ◽  
Vol 6 (3) ◽  
Author(s):  
R. Preethi ◽  
P. Padma
Keyword(s):  
Zeta Potential ◽  
Vitis Vinifera ◽  
Silver Ions ◽  
Seed Extract ◽  
Polydispersity Index ◽  
Potential Range ◽  
Visible Spectroscopy ◽  
Grape Seeds ◽  
X Ray ◽  
Uv Visible

The study focused on the green synthesis of silver nanobioconjugates (AgNPs) from phenolic-rich fruit source, Vitis vinifera seed extract and its major component phenolic, resveratrol respectively. Sunlight exposure for 20 minutes was the method of choice for the synthesis of AgNPs of the extract as well as the phenolic, resveratrol. The synthesized nanobioconjugates were characterized using UV-Visible spectroscopy, Transmission electron microscopy (TEM), Energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), Polydispersity index, Zeta potential and Fourier transform infrared spectroscopy (FTIR). The reduction of silver ions was confirmed by UV-visible spectroscopy with peaks at 440nm for both nanobioconjugates synthesized from seed extract and compound. The nanobioconjugates showed the spherical in shape with 14-35nm in size and crystalline in nature. The conjugates are well dispersed with 0.301 and 0.287 polydispersity index and the zeta potential range at -13.6 and -14.3mV for stability. The FTRI data proved that the components in grape seeds act as good reductants and stabilizers for the silver nanobioconjugate synthesis. All the synthesized nanobioconjugates exhibited steady and sustained release of the medicinal components conjugated, proving their druggability, and were biocompatible with human cells, demonstrating their safety. The findings of the study validate the anticancer properties of silver nanobioconjugates of Vitis vinifera and its active component resveratrol.

Study on integration of aluminum-doped zinc oxide (AZO) thin films with graphene oxide (GO)

2018 ◽  
Vol 32 (19) ◽  
pp. 1840044
Author(s):  
Aditya Dalal ◽  
Animesh Mandal ◽  
Shubhada Adhi ◽  
Kiran Adhi
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Aluminum Doped Zinc Oxide ◽  
Uv Visible

Aluminum (0.5 at.%)-doped ZnO (AZO) thin films were deposited by pulsed laser deposition technique (PLD) in oxygen ambient of 10[Formula: see text] Torr. The deposited thin films were characterized by x-ray diffraction (XRD), photoluminescence (PL), Raman spectroscopy and uv–visible spectroscopy (UV–vis). Next, graphene oxide (GO) was synthesized by Hummers method and was characterized by XRD, UV–vis spectroscopy, Raman spectroscopy and transmission electron microscopy (TEM). Thereafter, GO solution was drop-casted on AZO thin films. These films were then characterized by Raman Spectroscopy, UV–vis spectroscopy and PL. Attempt is being made to comprehend the modifications in properties brought about by integration.

In Situ Polymerization and Characterization of Poly(ε-caprolactone)/Layered Double Hydroxide Nanocomposites

2012 ◽  
Vol 557-559 ◽  
pp. 371-374
Author(s):  
Lian Liu ◽  
Teng Yu ◽  
Pei Wang ◽  
Guang Shuo Wang
Keyword(s):  
Layered Double Hydroxide ◽  
In Situ Polymerization ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Uv Visible ◽  
Absorbance Peak ◽  
Double Hydroxide

Nanocomposites of poly(ε-caprolactone) (PCL) and layered double hydroxide (LDH) were prepared by in situ polymerization at low LDHs loadings in this work. The resultants were characterized by FTIR spectroscopy, X-ray diffraction (XRD), differential scanning calorimeter (DSC) and UV-visible spectroscopy (UV-vis). FTIR showed that the PCL/LDHs nanocomposites were prepared successfully by in situ polymerization and XRD spectra showed that the crystal structure did not change greatly in the presence of LDHS. DSC results confirmed that LDHs could act as nucleating agents. UV-vis spectra showed that LDHs had stronger absorbance peak than LDH. Moreover, the PCL/LDHs nanocomposites had strong anti-ultraviolet effect by introduction of LDHs into polymer matrix.

scholarly journals Extent of Reduction of Vanadium Oxides during Catalytic Oxidation of Alkanes Measured by in-Situ UV−Visible Spectroscopy

2004 ◽  
Vol 108 (7) ◽  
pp. 2345-2353 ◽  
Author(s):  
Morris D. Argyle ◽  
Kaidong Chen ◽  
Carlo Resini ◽  
Catherine Krebs ◽  
Alexis T. Bell ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Vanadium Oxides ◽  
Visible Spectroscopy ◽  
Uv Visible

Synthesis of New Hexakis-Heterocyclic Compounds and their Use in the Formation and Stabilization of Au and Ag Nanoparticles

2014 ◽  
Vol 976 ◽  
pp. 3-7
Author(s):  
María Isabel Montalvo-Sierra ◽  
Miriam A. Martins Alho ◽  
Ana María Herrera-Gonzalez ◽  
Jesús García-Serrano ◽  
Paola Belem Bocardo-Tovar
Keyword(s):  
Ir Spectroscopy ◽  
Ag Nanoparticles ◽  
Heterocyclic Compounds ◽  
Cyano Group ◽  
Cycloaddition Reaction ◽  
Aldehyde Group ◽  
Dipolar Cycloaddition ◽  
Vis Spectroscopy ◽  
Aldehyde Derivative

The stabilization of nanoparticles in solution is a challenge of major proportions, and avoiding the formation of aggregates and eventual coalescence of particles is directly linked to the conservation of its unique properties. In this work, we reported the synthesis of two hexakis-heterocyclic compounds, containing the tetrazole or 2-amino-1,3,4-thiadiazole group, respectively. The hexa-heterocyclic compounds were used in the synthesis and stabilization of Au and Ag nanoparticles. To obtain these molecules was used phosphonitrilic chloride trimer compound as core, which reacted with phenols properly substituted in theparaposition with either cyano or aldehyde group. The cyano group was successfully converted to the corresponding tetrazole using a 1,3-dipolar cycloaddition reaction with ammonium azide generatedin situ. In the case of aldehyde derivative, it was converted to the corresponding thiosemicarbazone, which was further cyclized using FeCl3. Compounds were characterized by RMN and IR spectroscopy. The UV-Vis spectroscopy was used for nanoparticles analysis.

scholarly journals Forensic Discrimination Potential of Blue, Black, Green, and Red Colored Fountain Pen Inks Commercially Used in Pakistan, by UV/Visible Spectroscopy, Thin Layer Chromatography, and Fourier Transform Infrared Spectroscopy

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Mehwish Sharif ◽  
Madeeha Batool ◽  
Sohail Chand ◽  
Zahoor Hussain Farooqi ◽  
Syed Azhar Ali Shah Tirmazi ◽  
...  
Keyword(s):  
Developing Countries ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Thin Layer ◽  
Ftir Spectroscopy ◽  
Visible Spectroscopy ◽  
Discriminating Power ◽  
Vis Spectroscopy ◽  
Uv Visible ◽  
Layer Chromatography

Examination and comparison of fountain pen inks are very important in forensic questioned documents examination in developing countries where the chances of fraud are greater in cases of cheques, marriage papers, entry of birth and death, etc. In this study, fountain pen inks of blue, black, green, and red colours that are commercially used in Pakistan have been discriminated by UV-Vis spectroscopy, TLC, and FTIR spectroscopy. We have calculated and compared the results in terms of discriminating power. UV/Visible Spectroscopy of fountain pen inks of different brands showed different composition despite their similar colours. TLC was effectively used to differentiate between the colored components of inks. FTIR results showed that each brand could be distinguished by studying the pattern of their absorption spectra that appeared due to the presence of different functional groups. On the basis of combined results of UV-VIS, TLC, and FTIR, the DP was found from 0.73-0.8 for blue, 0.80-1.0 for black, 0.5-1.0 for green, and 1.0 for red colored fountain pen inks. Overall, this study demonstrated the elevated worth of analysis of fountain pen inks commercially used in Pakistan as the study for fountain pen inks, while not very common, remains an interesting target study.

Spectral-Luminescence Properties of Water Dispersions of CdS and Ag Nanoparticles Stabilized with Na2SiO3

2016 ◽  
Vol 683 ◽  
pp. 325-330 ◽  
Author(s):  
Alexander A. Biryukov ◽  
Ekaterina Gotovtseva ◽  
Valery Svetlichnyi
Keyword(s):  
Surface Plasmon Resonance ◽  
Ag Nanoparticles ◽  
Sodium Metasilicate ◽  
Visible Range ◽  
Spectroscopy Data ◽  
Cds Quantum Dots ◽  
Visible Spectroscopy ◽  
Uv Visible ◽  
Average Size ◽  
Spectral Luminescence

It was shown, that using of sodium metasilicate (Na2SiO3) as stabilizing agent for CdS quantum dots or Ag nanoparticles in water leads to the formation of stable colloids of CdS/SiO32- and Ag/SiO32- particles. These colloids are active in the visible range of the spectrum. According to TEM and UV-visible spectroscopy data, an average size of the particles in colloids was ∼ 5 nm for CdS and 2-10 nm for Ag. Ag/SiO32- water colloids showed an absorption band with a maximum at 380-410 nm. This band belonged to surface plasmon resonance. CdS/SiO32- water dispersions were characterized by luminescence at the region of 500-800 nm. The luminescence intensity increased after addition of Ag+ into the colloids of CdS/SiO32-.

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