scholarly journals Fabrication and Characterization of MSQ Aerogel Coating on ePTFE Thin Films for Cable Sheaths

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1246 ◽  
Author(s):  
Xingzhong Guo ◽  
Shengchi Bai ◽  
Jiaqi Shan ◽  
Wei Lei ◽  
Ronghua Ding ◽  
...  

With methylsilsesquioxane (MSQ) aerogels synthesized by the sol-gel method as a raw material and Si-Ti sol as a binder, an alcohol-based aerogel slurry consisting of only MSQ aerogel and Si-Ti sol was prepared and coated on expanded polytetrafluoroethylene (ePTFE) to form an MSQ aerogel coating layer, followed by low-temperature heat treatment. The effect of Si-Ti sol content on the microstructure of the MSQ aerogel coating layer was investigated, and the properties of a typical MSQ aerogel-layer-coated ePTFE film were evaluated. The results show that Si-Ti sol has an important role in terms of film-forming capability, surface smoothness, flexibility, and powder dropping of the MSQ aerogel coating layer. With a Si-Ti sol of 10.5 wt.% content as a binder and after heat treatment at 170 °C for 30 min, the coated ePTFE flexible thin film with a layer thickness of 30 μm shows high uniformity, integrity, and electrical insulation properties, with an elongation at break decrease over 130%, a thermal conductivity of 0.1753 W/(m·K) at 25 °C, a dielectric constant of 16.5674, and a dielectric loss of 0.06369, which can be promisingly applied in cable sheaths.

2019 ◽  
Vol 35 (1) ◽  
pp. 221-227
Author(s):  
Maulida Lubis ◽  
Mara Bangun Harahap ◽  
Iriany Iriany ◽  
Muhammad Hendra S. Ginting ◽  
Iqbal Navissyah Lazuardi ◽  
...  

Cooking oil waste that has been disposed could contamine the environment. However, if it is processed well, it can potentially become a raw material of polyurethane. The aim of this study was to determine the best polyurethane on the tensile strength, impact strength, elongation at break, water absorption, characterization of Fourier Transform Infra-Red (FTIR) and the characterization of Scanning Electron Microscopy (SEM). The variables used in this study were ambient process temperature with 440 rpm stirring speed, 1-minute stirring time, the ratio of polyoland WCO was 7:3 (% w/w), and the ratio of Toluene Diisocyanate (TDI) and WCO was 1:1; 1:2; 1:3; 1:4 (% w/w). The results obtained from the analysis of the best tensile strength against the polyurethane synthetic was in the 1:1 ratio of mixed variations between oil and TDI with a value of 0.403 MPa. The best impact strength was in the ratio of mixed variations between oil and TDI with 1:4 (% w/w) with a value of 600.975 J/m2. The best elongation at break against polyurethane foam synthetic was in the 1:3 ratio of mixture variations of oil and TDI with a value of 4.506%.


2019 ◽  
Vol 43 (21) ◽  
pp. 8315-8324
Author(s):  
Hui Yang ◽  
Rui Wang ◽  
Yaozu Wang ◽  
Jianzhong Jiang ◽  
Xingzhong Guo

Macroporous europium-doped Ca12Al14O33 (C12A7:Eu3+) was prepared via a sol–gel method followed by heat-treatment, and the resultant macroporous C12A7:Eu3+ shows potential for practical application in metal ion detection and has a good response to Pb2+ ions.


Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1027
Author(s):  
Beata Smyrak ◽  
Bartosz Jurkiewicz ◽  
Małgorzata Zasadzińska ◽  
Marek Gniełczyk ◽  
Patryk Jałowy

The raw material for the production of Al-Mg-Si wires is wire rods, created in the Continuus Properzi line in temper T1 (cooled after forming at an elevated temperature and after natural aging). The general technologies for shaping the mechanical and electrical properties of Al-Mg-Si wire rods include two kinds: high- and low-temperature heat treatments. High-temperature heat treatment includes a homogenization process and a supersaturation process. Low-temperature heat treatment takes place after supersaturation and includes natural or artificial aging. This study shows how the amount of Mg and Si influences the mechanical and electrical properties of EN-AW 6101 wire rods after different kinds of heat treatments. As the general aim of this study was to determine the effect of the material’s temper on its mechanical and electrical properties, the research considered the initial parameters of the starting materials being examined. These parameters can be modified by selecting the chemical composition of the Al-Mg-Si alloy and the value of precipitation hardening obtained with artificial.


Author(s):  
Yinan Tian ◽  
Yung C. Shin ◽  
Galen B. King

Two-photon polymerization is a powerful technique in fabricating three dimensional sub-diffraction-limited structures. Recently, new sol-gel material, SZ2080, was introduced into two-photon polymerization and was proved to be better than the conventional materials for its negligible shrinkage. In this paper, two-photon polymerization was applied to generate woodpile structures, one kind of photonic crystal, using SZ2080. First, the relationship between scanning speed, laser power and resolution was determined through fabricating free-hanging lines. Based on this relationship, woodpile structures with different period distances were fabricated with high uniformity as shown by SEM images. Then optical properties of woodpile structures were investigated using Fourier Transform Infrared Spectroscopy (FTIR) and a quantitative relationship between band gap and period distance was established.


2013 ◽  
Vol 537 ◽  
pp. 205-208
Author(s):  
Xiao Qiang Wang ◽  
Yue Liu Li ◽  
Jian Min Wang ◽  
Jing Guo ◽  
Ming Ya Li

In this work, nanocrystalline TiO2 powder was prepared by the sol-gel method via tetrabutyl titanate as raw material, non-ion surfactant TO8 as a template. Then the nanocrystalline TiO2 thin film electrodes which were coated on FTO glass substrates via the slurry consiting of TiO2 powder prepared by us and the trabutyl titanate precursor were successfully prepared by using a simple and convenient hydrothermal method at low temperature. The structure and morphology of powders and films were characterized by X-ray diffraction, scanning electric microscopy. The influence factors on the samples were discussed. The photoelectric properties of cells assembled by the films were measured. The results show that, at 25°C and under 1000W/m2 light intensity,open voltage is 708mV, Jsc is 14.648mA/cm2, fill factor is 53.788, the conversion efficiency is 5.5988%.


2013 ◽  
Vol 591 ◽  
pp. 66-69
Author(s):  
Ying Na Zhao ◽  
Meng Zhang ◽  
Jiang Ren ◽  
Xiong Feng Zeng

The modified mullite fiber was used to toughen the mullite ceramic, which can effectively overcome the brittleness of ceramic materials and improve the material strength and toughness. Using 8ZrOCl2•H2O as precursor, anhydrous ethanol as solvent, H2O2 as hydrolysis promoter and NH3·H2O as precipitant, the stable and transparent zirconium sol could be obtained by sol-gel process, which coated mullite short fiber. The results showed that the stable and transparent ZrO2 sol was obtained when pH value was 3.8~4.8 and reaction temperature was at 25°C. XRD results indicated that monoclinic ZrO2 particles grew up and formed after heat-treatment at 700°C. The coating ZrO2 film combined with mullite fiber homogeneously and closely, and the film thickness was about 1 μm.


2017 ◽  
Vol 899 ◽  
pp. 572-575
Author(s):  
Daniel Rodrigues ◽  
Gilberto Vicente Concílio ◽  
Jose Adilson de Castro ◽  
Marcos Flavio de Campos

Compression moulded rare earth magnets are used in many applications, and one of them is in electrical motors, which can operate at temperatures as high as 150 °C. In high temperatures, oxidation and phase transformations may affect magnetic properties. Another issue to be considered is polymer degradation. In this paper cylindrical samples of a commercial ready-to-press raw material (MQPB+, Molycorp-Magnequench) were pressed to densities close to 5.50 g/cm3. These samples were cured (low temperature heat treatment) and thermal aged at 200 °C for 72 hours, under dynamic air. Physical characteristics (weight, dimensions and densities) and magnetic properties were measured at room temperature in a TCH2020 hysteresigraph (Globalmag). Degradation of magnetic properties was observed, and oxidation seems to be the main reason.


1993 ◽  
Vol 310 ◽  
Author(s):  
Hidehiro Endo ◽  
M. J. Cima

AbstractEpitaxial formation of KNbO3 films on several substrates was examined. The films were prepared by a sol-gel process using potassium ethoxide and niobium pentaethoxide. Hetero-epitaxial KNbO3 films with (100) orientation were successfully obtained both on MgO (100) and SrTiO3 (100) substrates by heat treatments above 700°C, while polycrystalline KNbO3 were formed on Si (111) substrates. Higher temperatures and extended soaking time promoted the grain growth of KNbO3 and KNbO3 films with improved surface morphologies (smoother surfaces) could be obtained by controlling heat treatment parameters.


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