scholarly journals Natural and Activated Allophane Catalytic Activity Based on the Microactivity Test in Astm Norm 3907/D3907M-2019

2020 ◽  
Vol 10 (9) ◽  
pp. 3035
Author(s):  
Edward Henry Jiménez Calderón ◽  
Ana Emperatriz Paucar Tipantuña ◽  
Paulina Fernanda Herrera Mullo ◽  
Daniel Alejandro Hidalgo Cháfuel ◽  
Washington Ruiz ◽  
...  
Keyword(s):  
Analytical Techniques ◽  
Bet Surface Area ◽  
Navier Stokes ◽  
Maximum Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Catalytic Activation ◽  
Atomic Force ◽  
Activating Agent

The optimal conditions of the catalytic activation of allophane were evaluated for possible use as a catalyst within a fluidized bed catalytic cracking unit (FCC). The physicochemical properties of natural allophane and activated allophane were studied by using an alkaline activating agent, followed by a hydrothermal treatment. For the characterization, analytical techniques were used: Fourier transform infrared spectroscopy, particle size, (BET) surface area, thermogravimetry (TGA), X-ray diffraction (XRD), chemisorption, X-ray fluorescence (XRF), atomic force microscopy (AFM), and chromatography. The catalytic evaluation was determined by the (MAT) micro activity test equipment constructed according to ASTM D-3907/D3907M-2019. In addition, the Navier–Stokes 3D equations (nonlinear partial derivatives) were studied, which allow studying molecular dynamics contributing substantively to chemical kinetics describing the process of decomposition of crude oil in thermal cracking, determining the maximum temperature at which it retains its properties through the action of heat.

Use of Allophane as Face Mask Filter for Coronaviruses (Sars-Cov-2)

2021 ◽  
Vol 878 ◽  
pp. 62-72
Author(s):  
Edward H. Jiménez Calderon ◽  
Marco Rosero ◽  
Magdalena Diaz
Keyword(s):  
Analytical Techniques ◽  
Face Mask ◽  
Bet Surface Area ◽  
Navier Stokes ◽  
Technological Problem ◽  
Active Centers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Organic Surfactant ◽  
Area X

The traditional mouth cover masks can be made by hand. But with the arrival of the Coronavirus pandemic, these masks have special requirements and we will have to use these until at least 2022. Therefore, the current technological problem is what must be the appropriate filter nanomaterial (cuprum, zinc, zeolite or Allophane) to absorb and/or destroy coronaviruses. In addition, the preparation of this specific purpose mask must be certified, easy to manufacture and inexpensive. Taking these requirements into account, there is a suitable nanomaterial called Allophane, which has active centers of silicon and aluminum (Si / Al), which rapidly absorb micro droplets and nanodrops of water [3, 5] nm. Coronaviruses are microscopically embedded in water droplets. To build an absorbent filter that also destroys coronaviruses, we can use some organic surfactant in optimal proportions and that works cooperatively with Allophane. The physicochemical properties of natural Allophane were studied. For the characterization, analytical techniques were used: Fourier transform infrared spectroscopy (FTIR), BET surface area, X-ray diffraction (XRD), Chemisorption and Atomic Force Microscopy (AFM). In addition, the Navier Stokes 3D equations were studied, which allow us studying molecular dynamics contributing substantively to chemical kinetics describing the process of absorption of water and decomposition of water + coronavirus.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Low Molecular Weight Microfibers with Light Sensing Properties

2017 ◽  
Vol 54 (4) ◽  
pp. 655-658
Author(s):  
Andrei Bejan ◽  
Dragos Peptanariu ◽  
Bogdan Chiricuta ◽  
Elena Bicu ◽  
Dalila Belei
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Force Microscopy ◽  
Light Sensing ◽  
Sensing Applications ◽  
Atomic Force ◽  
Low Molecular Weight Compounds

Microfibers were obtained from organic low molecular weight compounds based on heteroaromatic and aromatic rings connected by aliphatic spacers. The obtaining of microfibers was proved by scanning electron microscopy. The deciphering of the mechanism of microfiber formation has been elucidated by X-ray diffraction, infrared spectroscopy, and atomic force microscopy measurements. By exciting with light of different wavelength, florescence microscopy revealed a specific optical response, recommending these materials for light sensing applications.

Nanocrystalline Solutions as Precursors to The Spray Deposition of Cdte Thin Films

1995 ◽  
Vol 382 ◽  
Author(s):  
Martin Pehnt ◽  
Douglas L. Schulz ◽  
Calvin J. Curtis ◽  
Helio R. Moutinho ◽  
Amy Swartzlander ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Cdte Nanoparticles ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Cdte Thin Films

ABSTRACTIn this article we report the first nanoparticle-derived route to smooth, dense, phase-pure CdTe thin films. Capped CdTe nanoparticles were prepared by injection of a mixture of Cd(CH3)2, (n-C8H17)3 PTe and (n-C8H17)3P into (n-C8H17)3PO at elevated temperatures. The resultant nanoparticles 32-45 Å in diameter were characterized by x-ray diffraction, UV-Vis spectroscopy, transmission electron microscopy, thermogravimetric analysis and energy dispersive x-ray spectroscopy. CdTe thin film deposition was accomplished by dissolving CdTe nanoparticles in butanol and then spraying the solution onto SnO2-coated glass substrates at variable susceptor temperatures. Smooth and dense CdTe thin films were obtained using growth temperatures approximately 200 °C less than conventional spray pyrolysis approaches. CdTe films were characterized by x-ray diffraction, UV-Vis spectroscopy, atomic force microscopy, and Auger electron spectroscopy. An increase in crystallinity and average grain size as determined by x-ray diffraction was noted as growth temperature was increased from 240 to 300 °C. This temperature dependence of film grain size was further confirmed by atomic force microscopy with no remnant nanocrystalline morphological features detected. UV-Vis characterization of the CdTe thin films revealed a gradual decrease of the band gap (i.e., elimination of nanocrystalline CdTe phase) as the growth temperature was increased with bulk CdTe optical properties observed for films grown at 300 °C.

Frequency and Temperature Dependence of Dielectric Properties of Orthorhombic HoMnO3 Thin Films

2014 ◽  
Vol 1025-1026 ◽  
pp. 427-431
Author(s):  
Ping Gao ◽  
Wei Zhang ◽  
Wei Tian Wang
Keyword(s):  
Dielectric Properties ◽  
Pulsed Laser ◽  
Signal Amplitude ◽  
Debye Model ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cole Diagram

Orthorhombic HoMnO3 films were prepared epitaxially on Nb-doped SrTiO3 single crystal substrates by using pulsed laser deposition technique. The films showed perfectly a-axis crystallographic orientations. X-ray diffraction and atomic force microscopy were used to characterize the films. The complex dielectric properties were measured as functions of frequency (40 Hz~1 MHz) and temperature (80 K~300 K) with a signal amplitude of 50 mv. The respective dielectric relaxation peaks shifted to higher frequency as the measuring temperature increased, with the same development of real part of the complex permittivity. The cole-cole diagram was obtained according to the Debye model, and the effects of relaxation process were discussed.

Lateral Size of Self-Patterned Nanostructures Controlled by Multi-Step Deposition

2005 ◽  
Vol 106 ◽  
pp. 117-122 ◽  
Author(s):  
Izabela Szafraniak ◽  
Dietrich Hesse ◽  
Marin Alexe
Keyword(s):  
Electron Microscopy ◽  
Ultrathin Films ◽  
Lateral Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Non Volatile Memory ◽  
Ferroelectric Capacitors ◽  
Scanning Electron

Self-patterning presents an appealing alternative to lithography for the production of arrays of nanoscale ferroelectric capacitors for use in high density non-volatile memory devices. Recently a self-patterning method, based on the use of the instability of ultrathin films during hightemperature treatments, was used to fabricate nanosized ferroelectrics. This paper reports the use of the method for the preparation of PZT nanoislands on different single crystalline substrates - SrTiO3, MgO and LaAlO3. Moreover, a multi-step deposition procedure in order to control lateral the dimension of the crystals was introduced. The nanostructures obtained were studied by atomic force microscopy, scanning electron microscopy and X-ray diffraction.

scholarly journals Influence of the growth parameters of TiO2 thin films deposited by the MOCVD method

Cerâmica ◽  
2002 ◽  
Vol 48 (305) ◽  
pp. 38-42 ◽  
Author(s):  
M. I. B. Bernardi ◽  
E. J. H. Lee ◽  
P. N. Lisboa-Filho ◽  
E. R. Leite ◽  
E. Longo ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Parameters ◽  
Structural Characteristics ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Deposition Parameters

The synthesis of TiO2 thin films was carried out by the Organometallic Chemical Vapor Deposition (MOCVD) method. The influence of deposition parameters used during growth on the final structural characteristics was studied. A combination of the following experimental parameters was studied: temperature of the organometallic bath, deposition time, and temperature and substrate type. The high influence of those parameters on the final thin film microstructure was analyzed by scanning electron microscopy with electron dispersive X-ray spectroscopy, atomic force microscopy and X-ray diffraction.

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