The influence of annealing atmosphere on the material properties of sol–gel derived SnO2:Sb films before and after annealing

2012 ◽  
Vol 258 (16) ◽  
pp. 5981-5986 ◽  
Author(s):  
Jiann-Shing Jeng
Keyword(s):  
Material Properties ◽  
Sol Gel ◽  
Annealing Atmosphere ◽  
Before And After

Silica Sol-Gel Supported Nickel Nano-Catalyst for Hydrogen Production Using Microreactors

2005 ◽  
Vol 885 ◽  
Author(s):  
Krithi Shetty ◽  
Shihuai Zhao ◽  
Wei Cao ◽  
Naidu V. Seetala ◽  
Debasish Kuila
Keyword(s):  
Steam Reforming ◽  
Average Pore Size ◽  
Sol Gel ◽  
Supported Catalyst ◽  
Silica Sol ◽  
Average Pore ◽  
Steam Reforming Of Methanol ◽  
Nano Catalyst ◽  
Before And After ◽  
Reforming Reactions

ABSTRACTThe goal of this research is to investigate the activities of a non-noble nano-catalyst (Ni/SiO2) using Si-microreactors for steam reforming of methanol to produce hydrogen for fuel cells. The supported catalyst was synthesized by sol-gel method using Ni (II) salts and Si(C2H5O)4 as starting materials. EDX results indicate that the actual loading of Ni (5-6%) is lower than the intended loading of 12 %. The specific surface area of the silica sol-gel encapsulated Ni nano-catalyst is 452 m2/g with an average pore size of ∼ 3 nm. Steam reforming reactions have been carried out in a microreactor with 50 µm channels in the temperature range of 180-240 °C and atmospheric pressure. Results show 53% conversion of methanol with a selectivity of 74 % to hydrogen at 5 l/min and 200 °C. The magnetic properties of the catalysts were performed using a Vibrating Sample Magnetometer (VSM) to study the activity of the catalysts before and after the steam reforming reactions. The VSM results indicate much higher activity in the microreactor compared to macro-reactor and Ni forms non-ferromagnetic species faster in the microreactor.

Evaluating Mechanical Properties of Ceramics by Relative Methods

2007 ◽  
Vol 336-338 ◽  
pp. 2406-2410
Author(s):  
Yi Wang Bao ◽  
Xiao Xue Bu ◽  
Yan Chun Zhou ◽  
Li Zhong Liu
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Ceramic Coatings ◽  
Relative Method ◽  
Tempered Glass ◽  
Theoretic Analysis ◽  
Surface Strength ◽  
Indirect Approach ◽  
Before And After ◽  
The Relationship

A relative method, defined as indirect approach to evaluate the material properties via the relationship between unknown properties and a known property, is proposed to estimate some properties that could not be measured by the traditional methods for ceramics. Experiments and theoretic analysis based on the relative method were carried out in this study to estimate the properties in following aspects: determining the temperature dependence of elastic modulus of some machineable ceramics by comparing the deflections; obtaining the modulus and strength of ceramic coatings supported by substrates, from the variation in properties of the rectangular beam samples before and after coating; estimating the residual stresses in tempered glass by comparing the change in the surface strength after strengthening.

Photocatalytic and Self-cleaning Properties of Titania Coatings Prepared by Inkjet Direct Patterning of a Reverse Micelles Sol-gel Composition

2012 ◽  
Vol 15 (1) ◽  
Author(s):  
Petr Dzik ◽  
Magdalena Morozová ◽  
Petr Klusoň ◽  
Michal Veselý
Keyword(s):  
Material Properties ◽  
Reverse Micelles ◽  
Degradation Rate ◽  
Sol Gel ◽  
Basic Material ◽  
Fatty Acid Degradation ◽  
Direct Patterning ◽  
Atomic Force ◽  
Titania Coatings ◽  
Gel Composition

AbstractAn optimized reverse micelles sol-gel composition was deposited by inkjet direct patterning onto glass supports. Experimental “material printer” Fujifilm Dimatix 2831 was used for sol patterning. Printing was repeated up to 4 times in wet-to-dry manner and photocatalytic coatings of various thickness were obtained after final thermal calcination. Basic material properties of prepared coating were studied by optical microscopy, electron and atomic force imaging, Raman, XRD and UV-VIS spectrometry. Photocatalytic activity was evaluated by dye and fatty acid degradation rate as well as photoinduced hydrophilic conversion rate. Reverse micelles proved to be viable synthetic route for the preparation of titania coatings with even structure and their compatibility with inkjet direct patterning deposition was demonstrated.

scholarly journals Enhancement the Sensitivity of waveguide Coated ZnO thin films: Role of Plasma Irradiation

2020 ◽  
Vol sceeer (3d) ◽  
pp. 93-98
Author(s):  
Marwan Younus ◽  
Muayad Ahmed ◽  
Ghazwan Ali
Keyword(s):  
Thin Films ◽  
Glucose Solution ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Dielectric Barrier Discharge Plasma ◽  
Dbd Plasma ◽  
Plasma Irradiation ◽  
Before And After ◽  
Barrier Discharge Plasma

In this study, Dielectric Barrier Discharge plasma irradiation (DBD) is applied to treatment and improve the properties of the ZnO thin film deposited on the glass substrate as a sensor for glucose detection. The ZnO is prepared via a sol-gel method in this work. ZnO is irradiated by the DBD high voltage plasma to improve of its sensitivity. The optical properties, roughness and surface morphology of the waveguide coated ZnO thin films before and after DBD plasma irradiation are studied in this work. The results showed a significant improvement in the performance of the sensor in the detection of concentrations of glucose solution after plasma irradiation. Where the largest value in sensitivity was equal to 62.7 when the distance between electrodes was 5 cm compared to the sensitivity before irradiation, which was equal to 92. The high response showed in results demonstrating that the fabricated waveguide coated ZnO after plasma irradiation has the excellent potential application as a sensor to detect small concentration of glucose solution.

Synthesis and Film Investigation of Titania

2013 ◽  
Vol 832 ◽  
pp. 128-131
Author(s):  
Sharipah Nadzirah ◽  
Uda Hashim
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Titanium Dioxide ◽  
Sol Gel ◽  
Titanium Butoxide ◽  
Before And After ◽  
Scanning Electron ◽  
Spin Coater

Titania or titanium dioxide (TiO2) thin film has been synthesized via sol-gel method with monoethanolamine (MEA) as a catalyst. The mixing of titanium butoxide as a precursor, ethanol as a solvent and MEA were stirred using magnetic stirrer under ambient temperature [. The TiO2solution prepared then was deposited on SiO2substrates using spin-coater and the coated films were annealed at 600°C. Finally, both before and after annealed TiO2thin films were characterized using Field Emission Scanning Electron Microscopy (FESEM). The obtained results show the different TiO2particles formation before and after annealed.

Curling and Annealing Study of Sputtered Thin Spinel Films Delaminated from Lift-Off Polyimide

1997 ◽  
Vol 505 ◽  
Author(s):  
Rand Dannenberg ◽  
Alexander H. King ◽  
Richard J. Gambino ◽  
Alan J. Doctor
Keyword(s):  
Driving Forces ◽  
Stress Gradient ◽  
Deposition Process ◽  
Radius Of Curvature ◽  
Annealing Atmosphere ◽  
High Electron ◽  
Nano Crystalline ◽  
Before And After ◽  
Lift Off ◽  
Beam Currents

ABSTRACTFilms of Mnl.56Co0.96Ni0.48O4, 6–10 ¼m thick, were RF-magnetron sputtered onto the high temperature lift-off polyimide PiRL®; (made by Brewer Science, Inc.), and patterned into long, narrow beams using photolithography. The beams would self-delaminate, curling towards the substrate upon cooling from 300°C to room temperature after sputtering, as a result of the stress gradient in the film, caused by the deposition process. The typical radius of curvature is 8000 ¼m. Upon annealing at temperatures as low as 250°C for 10 minutes, the delaminated films continue to curl. The films curl to equilibrium radii that are functions of the annealing atmosphere and temperature. Films annealed in H2/N2 or vacuum curl more slowly than in air. TEM reveals that the first 100 nm of film is relatively porous, nanocrystalline spinel which densify instantaneously when exposed to high electron beam currents. Analysis of TEM photographs before and after annealing at 250°C indicate that the level of porosity decreases in the films by 1% which can account for the change in the curl radius. The first layers of film at the PiRL-film interface are prevented from fully densifying while on the substrate. When the film delaminates and the constraint is removed, the initial layer can densify, sintering at low temperature because the large specific surface area of the nano-crystalline microstructure provides high driving forces. The nature of the substrate-induced constraint is not fully understood. Water vapor and other light elements may be released from the polyimide if it were to continue to imidize during the deposition, and a SIMS study has been undertaken to investigate this possibility. Alternatively, the constraint may be purely mechanical, where the sintering rate is reduced as in constrained sintering of films from slurry. This effect may be important to understand when ceramic films are patterned with lift-off techniques. Empirical expressions describing the curl are developed.

Structural, Textural and Thermal Characterization of Nano-Mg/Al Hydrotalcite before and after Cr (VI) Removal

2013 ◽  
Vol 755 ◽  
pp. 53-60
Author(s):  
Esthela Ramos Ramírez ◽  
Norma Leticia Gutiérrez Ortega ◽  
Cesar Augusto Contreras Soto ◽  
Gustavo Rangel Porras
Keyword(s):  
Crystalline Structure ◽  
Sol Gel ◽  
Textural Properties ◽  
Kinetic Studies ◽  
Thermal Characterization ◽  
Gel Method ◽  
Sol Gel Method ◽  
Before And After ◽  
Short Time

In this work there was studied the structural, textural and effect that has treat thermal on the removal of Cr (VI) of nanoMg/Al hydrotalcite (NHT) synthesized by the sol-gel method with a ratio of Mg/Al=3. These present the characterization of the nanoMg/Al hydrotalcite before and after Cr (VI) removal, as well as the kinetic studies and of balance. In agreement with the results, when the NHT are thermal treated to 350 °C the hydrotalcite crystalline structure remains but the textural properties are improved and structural. The NHT synthesized by the sol-gel method present a good capacity of removal with values of 91 mg of Cr (VI) removed / g of NHT. The above mentioned capacity of removal gets improved after thermal treating the material, reaching values of removal of 124 mg of Cr (VI) removed / g of NHT. The NHT with the Cr (VI) absorbed show decrease of the crystalline structure, as well as a saturation of the pores that annuls the porosity due to the fact that the Cr (VI) lodges both at the pores and at the intersheets. The time that him takes the HLM to remove the Cr (VI) of the watery solution is alone of 2 minutes, with which it is possible to conclude that the NHT have an excellent aptitude to remove Cr (VI) of watery solutions in an interval of very short time.

Microstructure of Porous V2O-CeO2-SiO2 Catalyst for SCR of NO with NH3 at Low Temperature

2014 ◽  
Vol 875-877 ◽  
pp. 213-217 ◽  
Author(s):  
Mohd Razali Sohot ◽  
Umi Sarah Jais ◽  
Muhd Rosli Sulaiman
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Catalytic Reduction ◽  
Sol Gel ◽  
Reduction Process ◽  
No Emission ◽  
Scr Of No ◽  
Before And After ◽  
The Right ◽  
Proven Method

Selective catalytic reduction (SCR) is a well-proven method to reduce NO emission. However, to choose the right catalyst that provides a surface for reaction between NO and ammonia at low temperatures is a challenging task for a catalysts developers. In an earlier study, we prepared V2O5-CeO2-SiO2 catalyst with increasing V2O5 content by sol-gel route and found that the catalytic activity improved with increasing the V2O5 loading up to 0.5%. The catalytic activity, however, dropped when V2O5 loading was about 1% and increased back when the loading of V2O5 was about 5%. In this study, we looked into the microstructural relationship to explain these findings. The microstructures of the catalysts before and after exposure to NO gas revealed that the catalysts with 0.2% and 0.5% V2O5 were more porous after the reduction process possibly due to improved breakdown of (NH4)HCO3 to NH3 by the possible interaction with the V2O5 and CeO2-containing catalysts which consequently resulted in a more efficient NO reduction to N2 and H2O at low temperature. The microstructure of the catalyst with 1% V2O5 content to 5%, improved back the efficiency although clogging by CeVO4 phase still possible due to its presence based on XRD. The well-ordered micropores before exposure to NO and the more efficient breakdown of (NH4)HCO3 could have contributed to increase back the catalytic activity at low temperature.

Experimental Investigation of Mechanical Behavior of a Polyamide before and after Constrained Groove Pressing Process

2018 ◽  
Vol 36 ◽  
pp. 25-36
Author(s):  
Mohammed Salah Bennouna ◽  
Benaoumeur Aour ◽  
Fatiha Bouaksa ◽  
Saad Hamzaoui
Keyword(s):  
Experimental Investigation ◽  
Mechanical Behavior ◽  
Tensile Properties ◽  
Material Properties ◽  
Hold Time ◽  
Thermoplastic Polymer ◽  
Processed Material ◽  
Before And After ◽  
Number Of Cycles ◽  
Number Of Passes

In this paper an experimental investigation of mechanical behavior of a thermoplastic polymer (polyamide PA 66) processed by constrained groove pressing (CGP) using several passes is presented. To this end, corrugating and straightening tools are designed and manufactured. The effects of the number of passes and the hold time on the mechanical behavior of the polyamide have been highlighted. The obtained results show that the material properties and the microstructure are significantly altered under CGP process. It has been found that the microhardness and the tensile properties have been progressed accordingly to the number of cycles, especially when the samples are processed using a hold time of five minutes. Hence, it can be concluded that this latter plays a very important role on the reorientation and stabilization of the microstructure when the processed material is a polymer.

scholarly journals In vitro bioactivity of Polyurethane/85S Bioglass composite scaffolds

2013 ◽  
Vol 11 (9) ◽  
pp. 1439-1446 ◽  
Author(s):  
Lachezar Radev ◽  
Darina Zheleva ◽  
Irena Michailova
Keyword(s):  
Sol Gel ◽  
Spherical Particles ◽  
Polymerization Reaction ◽  
In Vitro Test ◽  
In Vitro Bioactivity ◽  
Before And After ◽  
Vitro Test ◽  
Sbf Solution ◽  
Static Conditions

AbstractIn the present work Polyurethane (PU)/Bioglass (BG) composite materials were synthesized with different content of BG (10 and 20 mol.%) as filler. The 85S Bioglass was synthesized via polystep sol-gel method. The chemical composition of BG is 85SiO2-10CaO-5P2O5 (wt.%). The synthesis of PU was carried out by a two-step polyaddition reaction. The 85S BG was added in situ during the polymerization reaction. In vitro bioactivity of the prepared composites was examined in the presence of 1.5 SBF for 7 days in static conditions. The structure of synthesized PU/BG composites before and after in vitro test was determined by XRD, FTIR and SEM. XRD of the samples before in vitro test proved that the phase of γCa2P2O7 in the PU/20BG is visible. FTIR revealed the presence of urethane bond between OH-(from BG) and NCO groups (from PU). Based on FTIR results after in vitro test in 1.5 SBF solutions, A/B-carbonate containing hydroxyapatite (CO3HA) was formed. XRD proved that HA was formed on the surface of the samples, but Ca2P2O7 does not undergo any changes in the 1.5 SBF solution. SEM depicted the nano-HA agglomerated in spherical particles after immersion in 1.5 SBF for 7 days.

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