scholarly journals Solid State Photoreduction of Silver on Mesoporous Silica to Enhance Antifungal Activity

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2340
Author(s):  
Giulia Quaglia ◽  
Valeria Ambrogi ◽  
Donatella Pietrella ◽  
Morena Nocchetti ◽  
Loredana Latterini
Keyword(s):  
Solid State ◽  
Mesoporous Silica ◽  
Surface Defects ◽  
Antimicrobial Properties ◽  
Biofilm Growth ◽  
X Ray ◽  
Silica Nanocomposites ◽  
Transmission Electron ◽  
Silver Cations

A solid-state Ultraviolet-photoreduction process of silver cations to produce Ag0 nanostructures on a mesoporous silica is presented as an innovative method for the preparation of efficient environmental anti-fouling agents. Mesoporous silica powder, contacted with AgNO3, is irradiated at 366 nm, where silica surface defects absorb. The detailed characterization of the materials enables us to document the silica assisted photo-reduction. The appearance of a Visible (Vis) band centered at 470 nm in the extinction spectra, due to the surface plasmon resonance of Ag0 nanostructures, and the morphology changes observed in transmission electron microscopy (TEM) images, associated with the increase of Ag/O ratio in energy dispersive X-ray (EDX) analysis, indicate the photo-induced formation of Ag0. The data demonstrate that the photo-induced reduction of silver cation occurs in the solid state and takes place through the activation of silica defects. The activation of the materials after UV-processing is then tested, evaluating their antimicrobial activity using an environmental filamentous fungus, Aspergillus niger. The treatment doubled inhibitory capacity in terms of minimal inhibitory concentration (MIC) and biofilm growth. The antimicrobial properties of silver–silica nanocomposites are investigated when dispersed in a commercial sealant; the nanocomposites show excellent dispersion in the silicon and improve its anti-fouling capacity.

SrTiO3 films on platinized (0001) Al2O3: Characterization of texture and nonstoichiometry accommodation

2004 ◽  
Vol 19 (5) ◽  
pp. 1477-1486 ◽  
Author(s):  
Dmitri O. Klenov ◽  
Troy R. Taylor ◽  
Susanne Stemmer
Keyword(s):  
Surface Defects ◽  
X Ray Diffraction ◽  
Pt Electrode ◽  
Lattice Match ◽  
Planar Defects ◽  
X Ray ◽  
Grain Sizes ◽  
Transmission Electron ◽  
Pt Films

Transmission electron microscopy and x-ray diffraction were used to study SrTiO3 films grown on platinized (0001) Al2O3 substrates. The Pt films were epitaxial with an orientation relationship described by (111)Pt‖(0001)Al2O3 and [110]Pt‖[10¯10]Al2O3. SrTiO3 films with two different Sr to Ti ratios, 1.02 and 1.4, were deposited by radio-frequency magnetron sputtering. In the film with a large amount of Sr excess, the grain sizes were smaller and a high density of planar defects was observed. The films were predominantly (111) textured, but a weaker (110) texture component was also found, independent of stoichiometry. While the (111) texture could be explained with the excellent lattice match with (111) Pt, the (110) textured grains had a large mismatch with the Pt electrode. We propose that the presence of the (110) oriented grains is due to nucleation at Pt surface defects. Planar defects in the films with a large amount of Sr excess served to accommodate the nonstoichiometry. Comparison with homoepitaxial SrTiO3 films showed that the density of planar defects in the SrTiO3 films on (111)Pt/Al2O3 is insufficient to accommodate all the excess Sr. The influence of the film microstructure on the dielectric properties is also discussed.

scholarly journals Fabrication and Characterization of CuInSe2Thin Film Applicable for a Solar Energy Light Absorption Material via a Low Temperature Solid State Reaction

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Kuo-Chin Hsu ◽  
Yaw-Shyan Fu ◽  
Pei-Ying Lin ◽  
I-Tseng Tang ◽  
Jiunn-Der Liao
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Low Temperature ◽  
Solid State Reaction ◽  
Light Absorption ◽  
Intermediate Phase ◽  
Energy Dispersive Spectrometer ◽  
X Ray ◽  
Transmission Electron

The chalcopyrite CuInSe2thin film synthesized via a low temperature solid state reaction from CuSe and InSe powders was investigated using X-ray diffractomy (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), and UV-vis absorption spectroscopy. CuSe and InSe phases react and directly transform into CuInSe2without the occurrence of any intermediate phase. The morphology of the newly formed CuInSe2crystalline was close to that of the CuSe reactant particle based on the TEM results, which indicate that the solid state reaction kinetics may be dominated by the In3+ions diffusion. The CuInSe2thin film prepared from the solid state reaction did not use the selenide process; its band gap might reach 1.06 eV, which is competent and suitable to be used for a thin film solar cell light absorption layer.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Current Status of Solid-State X-Ray Systems

1985 ◽  
Vol 43 ◽  
pp. 158-161
Author(s):  
Martin Peckerar ◽  
Anastasios Tousimis
Keyword(s):  
Solid State ◽  
Electric Fields ◽  
Spectral Lines ◽  
Current Status ◽  
Mobile Charge ◽  
Electron Hole ◽  
X Ray ◽  
Sensing Systems ◽  
Transmission Electron ◽  
Electron Microscopes

Solid state x-ray sensing systems have been used for many years in conjunction with scanning and transmission electron microscopes. Such systems conveniently provide users with elemental area maps and quantitative chemical analyses of samples. Improvements on these tools are currently sought in the following areas: sensitivity at longer and shorter x-ray wavelengths and minimization of noise-broadening of spectral lines. In this paper, we review basic limitations and recent advances in each of these areas. Throughout the review, we emphasize the systems nature of the problem. That is. limitations exist not only in the sensor elements but also in the preamplifier/amplifier chain and in the interfaces between these components.Solid state x-ray sensors usually function by way of incident photons creating electron-hole pairs in semiconductor material. This radiation-produced mobile charge is swept into external circuitry by electric fields in the semiconductor bulk.

scholarly journals Synthesis and characterization of Fe, Co, and Ni colloids in 2-mercaptoethanol

2020 ◽  
Vol 10 ◽  
pp. 184798042096688
Author(s):  
Galo Cárdenas-Triviño ◽  
Sergio Triviño-Matus
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Colloidal Dispersions ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Chemical Liquid Deposition ◽  
Liquid Deposition

Metal colloids in 2-mercaptoethanol using nanoparticles (NPs) of iron (Fe), cobalt (Co), and nickel (Ni) were prepared by chemical liquid deposition method. Transmission electron microscopy, electron diffraction, UV-VIS spectroscopy, and scanning electron microscopy with electron dispersive X-ray spectroscopy characterized the resulting colloidal dispersions. The NPs exhibited sizes with ranges from 9.8 nm for Fe, 3.7 nm for Co, and 7.2 nm for Ni. The electron diffraction shows the presence of the metals in its elemental state Fe (0), Co (0), and Ni (0) and also some compounds FeO (OH), CoCo2S4, and NiNi2S4.

Characterization of ordered mesoporous films on silicon (001) surface using X-ray and electron diffraction

2005 ◽  
Vol 38 (1) ◽  
pp. 211-216 ◽  
Author(s):  
Pang-Hung Liu ◽  
Kuei-Jung Chao ◽  
Xing-Jian Guo ◽  
Kuo-Ying Huang ◽  
Yen-Ru Lee ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Film ◽  
Continuous Film ◽  
X Ray ◽  
Transmission Electron ◽  
Ordered Mesoporous ◽  
Direction Dependence

A continuous silica film with well aligned mesochannels parallel to the Si(001) surface was found to be formed through sol–gel dip-coating of a silica precursor with nonionic ethylene oxide surfactant. Two two-dimensional mesoporous structures in centered and non-centered rectangular symmetries and with the short axes of elongated ellipsoidal pores normal to the surface were observed by X-ray and electron diffraction. Detailed transmission electron microscopy investigations were employed to view the direction dependence of the channel or pore packing in the continuous film.

Characterization of some mesogenic alkyl 1-thioglycosides

2002 ◽  
Vol 80 (8) ◽  
pp. 1162-1165 ◽  
Author(s):  
B Henrissat ◽  
G K Hamer ◽  
M G Taylor ◽  
R H Marchessault
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Solid State ◽  
Solid State Nmr ◽  
Liquid Crystalline ◽  
Liquid Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Liquid Crystalline Phases

A series of dodecyl 1-thio-β-D-glycosides has been synthesized and characterized (DSC, NMR, CP MAS, X-ray diffraction) as possible new marking materials with liquid-crystalline properties. These compounds undergo solid to liquid crystal phase transitions at various temperatures, which depend on the nature of the carbohydrate part of the structure. Their liquid-crystalline phases show extreme shear thinning behaviour.Key words: liquid crystal, powder X-ray diffraction, phase transition, thioglycoside, solid-state NMR, marking material

Detonation Synthesis of Nano-Size Materials

1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleation And Growth ◽  
Detonation Synthesis ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Size

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.

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