scholarly journals Obtaining the conductive SnO2 films by chemical bath deposition method

2019 ◽  
Vol 60 (11) ◽  
pp. 1-10
Author(s):  
Vladislav I. Rogozin ◽  
◽  
Vyacheslav F. Markov ◽  
Larisa N. Maskaeva ◽  
Anastasia E. Krasovskaya ◽  
...  
Keyword(s):  
Tin Dioxide ◽  
Solid Phase ◽  
Average Particle Size ◽  
Ammonium Fluoride ◽  
Contact Layer ◽  
Average Particle ◽  
Solution Ph ◽  
Before And After ◽  
Initial Salt ◽  
Conductive Properties

Thanks to such unique properties as transparency and conductivity tin dioxide often utilize as transparent contact layer to produce displays, solar cells, and sensor devices. Hydrochemical method of deposition SnO2 films is a perspective due to its simplicity, and economical efficiency. The ionic equilibria analysis was carried out and the boundary conditions of Sn(OH)2 solid phase formation in the «Sn2+ – H2O – OH‾» system calculated. It was established, that tin(II) hydroxide may be obtain in the range 2 < pH < 12. Preliminary results allow to determinate an optimal mixture sourness interval 1 < pH < 5. Revealed, that the thickness of the Sn(OH)2 films strongly depends on the solution pH. Maximum value of 488 nm reached at pH = 8. Conductive SnO2 layers were obtained on a glass and sitall substrates with simultaneously presence of antimony chloride and ammonium fluoride followed by annealing in air. The thickness vs temperature and thickness vs tin initial salt concentration dependences were installed. The uniform tin hydroxide layers with a thickness of ~74 nm may be synthesized under pH = 2 conditions. By the electron microscopy method the average particle size was established changing from 200 to 400 nm for as-synthesized films, to ~20 nm for annealed which indicates the nanostructure nature of the films. The morphology, elemental composition and conductive properties of deposited films were investigated before and after heating stage. Studying the annealing temperature influence at the film resistance were identified a three temperature ranges within which the films sharply differ in their conductive properties, which is associated with phase and structural transformations in them. Shown, that the most conductive SnO2 films with the omic resistance 3-5 kOm/sm were obtained at the temperature range 620-870 K.

scholarly journals Polymer Binders of Ceramic Nanoparticles for Precision Casting of Nickel-Based Superalloys

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1714
Author(s):  
Paweł Wiśniewski
Keyword(s):  
Solid Phase ◽  
Average Particle Size ◽  
Water Soluble ◽  
Ethyl Silicate ◽  
Average Particle ◽  
Precision Casting ◽  
Polymer Binders ◽  
Initial Stage ◽  
Nano Alumina ◽  
Solid Phase Content

This study presents the general characteristics of binders used in precision casting of Nickel-based superalloys. Three groups of binders were described: resins, organic compounds, and materials containing nanoparticles in alcohol or aqueous systems. This study also includes literature reports on materials commonly used and those recently replaced by water-soluble binders, i.e., ethyl silicate (ES) and hydrolysed ethyl silicate (HES). The appearance of new and interesting solutions containing nano-alumina is described, as well as other solutions at the initial stage of scientific research, such as those containing biopolymers, biodegradable polycaprolactone (PCL), or modified starch. Special attention is paid to four binders containing nano-SiO2 intended for the first layers (Ludox AM, Ludox SK) and structural layers (EHT, Remasol) of shell moulds. Their morphology, viscosity, density, reactions, and electrokinetic potential were investigated. The binders were characterized by a high solid-phase content (>28%), viscosity, and density close to that of water (1–2 mPa·s) and good electrokinetic stability. The nanoparticles contained in the binders were approximately spherically shaped with an average particle size of 16–25 nm.

scholarly journals Influence of Cu on the Improvement of Magnetic Properties and Structure of L10 FePt Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1097
Author(s):  
Luran Zhang ◽  
Xinchen Du ◽  
Hongjie Lu ◽  
Dandan Gao ◽  
Huan Liu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Annealing Temperature ◽  
Reduction Method ◽  
Solid Phase ◽  
Average Particle Size ◽  
Fept Nanoparticles ◽  
Average Particle ◽  
Phase Reduction ◽  
Different Temperatures ◽  
One Step

L10 ordered FePt and FePtCu nanoparticles (NPs) with a good dispersion were successfully fabricated by a simple, green, one-step solid-phase reduction method. Fe (acac)3, Pt (acac)2, and CuO as the precursors were dispersed in NaCl and annealed at different temperatures with an H2-containing atmosphere. As the annealing temperature increased, the chemical order parameter (S), average particle size (D), coercivity (Hc), and saturation magnetization (Ms) of FePt and FePtCu NPs increased and the size distribution range of the particles became wider. The ordered degree, D, Hc, and Ms of FePt NPs were greatly improved by adding 5% Cu. The highest S, D, Hc, and Ms were obtained when FePtCu NPs annealed at 750 °C, which were 0.91, 4.87 nm, 12,200 Oe, and 23.38 emu/g, respectively. The structure and magnetic properties of FePt and FePtCu NPs at different annealing temperatures were investigated and the formation mechanism of FePt and FePtCu NPs were discussed in detail.

scholarly journals Oxide Nanomaterials Based on SnO2 for Semiconductor Hydrogen Sensors

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
George Fedorenko ◽  
Ludmila Oleksenko ◽  
Nelly Maksymovych
Keyword(s):  
Tin Dioxide ◽  
Sol Gel ◽  
Average Particle Size ◽  
Fast Response ◽  
Average Particle ◽  
Hydrogen Sensors ◽  
Measuring Range ◽  
X Ray ◽  
Response And Recovery ◽  
Good Repeatability

Nanosized tin dioxide with an average particle size of 5.3 nm was synthesized by a sol-gel method and characterized by IR spectroscopy, TEM, X-ray, and electron diffraction. The obtained SnO2 can be used as initial material for creation of gas-sensitive layers of adsorption semiconductor sensors. Addition of palladium into the initial nanomaterial allows to improve response to hydrogen of such sensors in comparison with sensors based on undoped SnO2 and provides fast response and recovery time, a wide measuring range of hydrogen content in air ambient, and good repeatability of the sensor signal. Such promising properties could make useful the sensors based on these nanomaterials for devices intended to determine hydrogen in air.

Phase Formation, Crystal Structure and Ion Conductivity of Silver Antimonate-Molybdates

2020 ◽  
Vol 20 (7) ◽  
pp. 4597-4600
Author(s):  
Yu. A. Lupitskaya ◽  
D. A. Kalganov ◽  
L. Yu. Kovalenko ◽  
F. A. Yaroshenko
Keyword(s):  
Solid Phase ◽  
Rietveld Method ◽  
Structural Parameters ◽  
Average Particle Size ◽  
Structural Disorder ◽  
Synthesis Temperature ◽  
Average Particle ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Pyrochlore Type

The features of the formation of compounds based on silver antimonate obtained in the AgNO3–Sb2O3–MoO3 system by the solid-phase reaction were investigated. For a synthesis temperature of 1023 K, a homogeneous concentration region of the Ag2−xSb2−xMoxO6 solid solution with a structure of the defective pyrochlore type in the range of 0.0 ≤ x ≤ 2.0 was detected. The Rietveld method, within the constraints of the Fd-3m space group, was used to refinement of X-ray diffraction data, specify the structural parameters of powders, and the correlation of structural disorder with their electrically conductive properties. Relative density and average particle size for ceramic samples sintered at 1223 K were determined using scanning electron microscopy.

STRUCTURAL, OPTICAL AND GAS SENSING PROPERTIES OF ZnO, SnO2 AND ZTO NANOSTRUCTURES

NANO ◽  
2010 ◽  
Vol 05 (04) ◽  
pp. 185-194 ◽  
Author(s):  
O. A. FOUAD ◽  
G. GLASPELL ◽  
M. S. EL-SHALL
Keyword(s):  
Tin Dioxide ◽  
Driving Forces ◽  
Gas Sensing ◽  
Average Particle Size ◽  
Average Particle ◽  
Metal Powders ◽  
Semiconducting Nanostructures ◽  
20 Nm ◽  
Emission Studies ◽  
Sensing Characteristics

Tetrapods, nanobelts and polyhedron-shape like zinc oxide (ZnO) , tin dioxide (SnO2) nanostructures and ZnO/ZnSnO3/Zn2SnO4 (ZTO) composite functional semiconducting nanostructures have been synthesized successfully by the vapor–solid growth process. XRD analyses showed that ZnO with wurtzite, SnO2 with rutile and zinc stannate (ZnSnO3) and/or dizinc stannate (Zn2SnO4) with polyhedral crystal structure were condensed from the vapor phase when Zn and/or Sn metal powders individually or mixed were used as the starting materials. The driving forces for growth of these nanostructures were found to be vapor density, temperature, pressure and place of deposition from the source materials. Typically, the ZnO nanobelts have lengths of several hundred of nanometers and widths of about 10–15 nm. The average particle size of SnO2 are in the range of about 10–20 nm. Uniform hexagonal-shaped crystals of ZnO/ZnSnO3/Zn2SnO4 composite in the range of 50–300 nm as estimated from TEM images are observed. Based on the TEM, optical absorption and emission studies and the CO gas sensing characteristics of the prepared materials showed good crystal quality implying that the ZnO , SnO2 and ZnO/ZnSnO3/Zn2SnO4 nanostructures may suggest possible applications in optoelectronic devices and chemical gas sensors.

Impacts of Acid Treatment on the Characteristics of Native Corn Starch Granules

2011 ◽  
Vol 221 ◽  
pp. 72-77 ◽  
Author(s):  
Xin Jin ◽  
Shuan Qing Hou ◽  
Xiao Xu Sha ◽  
Liang Yu
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Acid Treatment ◽  
Corn Starch ◽  
Average Particle Size ◽  
Peak Temperature ◽  
Average Particle ◽  
Starch Granules ◽  
Acid Modification ◽  
Before And After

Native corn starches were acid-treated at 53 °C for hours in HCl aqueous solution. The peak temperature (Tp) and heat of gelatinization (ΔHgel) before and after treatments were determined. The average particle size, TG and viscosity were measured. The results showed that the viscosity of corn starch decreased from 630mPa to 4.6mPa after acid treatment for 6h. The average particle size decreased and ΔHgel decreased obviously after acid modification.

scholarly journals Reinforcement of Quaternary Ammonium Modified Silica (QAMS) with Magnetite and its Application by Solid Phase Adsorption (SPA) to Adsorb Chromate Ions

2020 ◽  
Vol 23 (10) ◽  
pp. 338-345
Author(s):  
Ngatijo Ngatijo ◽  
Restina Bemis ◽  
Abdul Aziz ◽  
Rahmat Basuki
Keyword(s):  
Solid Phase ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Average Particle ◽  
Modified Silica ◽  
Spherical Form ◽  
Chromate Ions ◽  
Chromium Vi ◽  
The Stability ◽  
Ph Range

Chromium (VI) in the form of chromate anions that have toxic properties needs to be overcome. This study aims to reinforce cationic sorbent quaternary amine-modified silica with magnetite (QAMS-Fe3O4) to adsorb chromate ions. QAMS prepared by reflux methylation ammine modified silica (AMS) obtained from destruction silicate from rice husk ash followed by the addition of 3-APTMS. Characterization QAMS-Fe3O4 by FT-IR showed successfully of methylation process indicated by disappearing absorbance at 1388 cm-1, and emerging absorbance at 2939 cm-1 in QAMS and QAMS-Fe3O4 indicated a transformation of N-H from -NH2 group to [-N+(CH3)3]. XRD analysis denotes 2θ = 30.15°, 35.53°, 43.12°, 57.22°, and 62.90° (JCPDS No. 00-033-0664) fathomed as a characteristic peak of magnetite. SEM-EDX reveals the homogenous topological spherical form with an average particle size 0.006 µm that is dominated by Si element (52.81%) with magnetic moment value = 34.1 emu/g. The stability test shows that this material stable in an acid condition. The adsorption of chromate ions was conducted by the SPA method. Optimal pH obtained by pH range 4-7 with more than 90% adsorbed chromate ions. Variation of increasing series flow rate from 0.05 to 1.5 mL min-1 resulted in decreased adsorbed chromate ions. The use of SPA methods offered simpler and easier handling than the batch method without overriding the adsorption process effectiveness.

scholarly journals Semiconductor Sensor With Loaded SnO2 Nanoparticles For Early Warning Of Indoor Fires

2019 ◽  
Vol Vol. 14, No.1 ◽  
pp. 37-42 ◽  
Author(s):  
Nelly Maksymovyc ◽  
Ludmila Oleksenko ◽  
Georgiy Fedorenko ◽  
Ganna Arinarkhova ◽  
Keyword(s):  
Early Warning ◽  
Tin Dioxide ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Average Particle ◽  
Sensitive Layer ◽  
Semiconductor Sensor ◽  
Wide Range

Nanosized tin dioxide material with an average particle size of 10-11 nm was prepared by a sol-gel method. The material has been tested as a gas sensitive layer of a semiconductor sensor. Platinum was introduced into the gas sensitive layer to increase the sensor response to hydrogen. It was shown that the Pt-containing sensor has high sensitivity to hydrogen: its electrical resistance changes in 9.2 times in the presence of 22 ppm H2 in air. It was demonstrated that the sensor applicable to a wide range of H2 measurements in air (3-935 ppm) and has a fast dynamic response. The sensor demonstrates rather good reproducibility of its signal to H2 and withstands hydrogen overload (935 ppm) without a loss of its sensitivity to H2 microconcentration (22 ppm). The results are prospective for applying the sensor in the detectors for early warning of indoor fires.

scholarly journals Adsorption-Semiconductor Sensor Based on Nanosized SnO2 for Early Warning of Indoor Fires

2021 ◽  
Author(s):  
Nelli Maksymovych ◽  
Ludmila Oleksenko ◽  
George Fedorenko
Keyword(s):  
Tin Dioxide ◽  
Early Stage ◽  
Dynamic Properties ◽  
Sol Gel ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Average Particle ◽  
Semiconductor Sensor ◽  
Wide Range

The paper is devoted for a solution of indoors fires prevention at early stage by determination of H2 (fire precursor gas) in air using a semiconductor sensor. A material based on Pt-containing nanosized tin dioxide with an average particle size of 10–11 nm obtained via a sol–gel method was created for a gas sensitive layer of the sensor. The developed sensor has high sensitivity to H2 micro concentration, a wide range of its detectable content in air, selectivity of H2 measuring in the presence of СО and СН4, good dynamic properties. The combination of these properties is very important for prevention of inflammations on their early stages before the open fires appearance. Economic benefit of the proposed sensor is due to a lower cost and higher reliability of the fire situation detection.

scholarly journals Preparation, characterization, and in vitro evaluation of amphiphilic peptide P12 and P12-DOX nanomicelles as antitumor drug carriers

2020 ◽  
Vol 10 ◽  
pp. 184798042091151 ◽  
Author(s):  
Ping Song ◽  
Wuchen Du ◽  
Wanzhen Li ◽  
Longbao Zhu ◽  
Weiwei Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Solid Phase ◽  
Average Particle Size ◽  
In Vitro Release ◽  
Drug Carriers ◽  
Average Particle ◽  
Polymer Micelles ◽  
Amphiphilic Peptide

Polymerized polypeptide nanomicelles have attracted much attention as novel drug carriers because of their good biocompatibility and degradability. To prepare doxorubicin (DOX)-loaded nanomicelles, an amphiphilic peptide, FFHFFH-KKGRGD (P12), was synthesized by solid-phase synthesis, and the physicochemical and drug-release properties, as well as the cytotoxicity of the nanomicelles, were evaluated in vitro. The P12-DOX polymer micelles were prepared by dialysis. The morphology and particle size were characterized by transmission electron microscopy and dynamic light scattering. The critical micelle concentration (CMC) of the polymer was determined by the probe method, and the drug-release characteristics of the micelles were studied by dynamic dialysis. The cytotoxicity and uptake of the P12-DOX micelles were evaluated against mouse breast cancer cells (4T1) and human umbilical vein endothelial cells. The peptide polymer micelles containing DOX were uniformly sized and had a spherical core–shell structure with an average particle size of 128.6 nm. The CMC of the polymer was low (0.0357 mg/mL). The in vitro release of DOX from the micelles is slow and is consistent with first-order kinetics. The copolymer micelles of the P12 polypeptide and DOX can be used as nanoscale spherical carriers of hydrophobic drugs and have broad applicability.

Sign in / Sign up

Export Citation Format

Share Document