Fabrication of Anti-Reflective Coatings on Solar Collector Tubes

2011 ◽  
Vol 306-307 ◽  
pp. 125-129 ◽  
Author(s):  
Yu Chao Niu ◽  
Guo Wei Huang ◽  
Ying Chen ◽  
Wen Wen Dou ◽  
De Ming Sun ◽  
...  

In order to reduce the reflection of solar collector cover tube and improve its transmissivity, a kind of SiO2anti-reflective coating on the cover tube was prepared using acid-base two-step sol-gel method. The surface morphology of the anti-reflective coating was observed using atomic force microscope and electronic scanning microscope. The scratch resistance of the coating was tested using pencil hardness apparatus. The transmissivity and anti-impact properties of the cover tube coated with the coating were measured respectively by means of the spectrophotometer and the relative standard method. The results showed that the anti-reflective coating possesses a higher scratch resistance and the coated cover tube has good transmissivity and anti-impact.

2006 ◽  
Vol 312 ◽  
pp. 339-344 ◽  
Author(s):  
Edmund Chwa ◽  
Linda Wu ◽  
Z. Chen

Sol-gel coatings with different amount of colloidal silica were prepared on polycarbonate substrate. The scratch resistance was measured by the pencil hardness test based on ASTM Standard D3363-00. The indentation hardness, elasticity modulus and fracture toughness of the coatings were also characterized and correlated to the observed pencil hardness. The scratch failure was found to be due to film cracking at the trailing end. Based on such an observation, the current analysis points out that the main factors towards scratch resistance are elasticity modulus, thickness and fracture toughness of the film.


2013 ◽  
Vol 743-744 ◽  
pp. 377-381
Author(s):  
Kai Bo Shen ◽  
Huan Yang ◽  
Jian Liu ◽  
Wei Wang ◽  
Yue Huang ◽  
...  

Distinguished with photoinduced super-hydrophilic inorganic thin films, non-photoinduced innate super-hydrophilic SiO2 thin films were successfully fabricated in this work. The SiO2 sol was prepared by acid-base two-step sol-gel method. The mix solution containing SiO2 sol and polyethylene glycol (PEG) was coated on glass substrate and then went through thermal treatment to obtain innate super-hydrophilic SiO2 thin films. The films were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and contact angle meter. The results show that the surface concave-convex microstructure and the hydroxyl content are the factors that endow the SiO2 coating films with innate super-hydrophilic property.


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1564
Author(s):  
Jong Tae Leem ◽  
Woong Cheol Seok ◽  
Ji Beom Yoo ◽  
Sangkug Lee ◽  
Ho Jun Song

EPOSS of polyhedral oligomeric silsesquioxanes (POSS) mixture structure and LPSQ of ladder-like polysilsesquioxane (LPSQ) structure were synthesized via sol–gel reaction. EPSQ had a high molecular weight due to polycondensation by potassium carbonate. The EPSQ film showed uniform surface morphology due to regular double-stranded structure. In contrast, the EPOSS-coated film showed nonuniform surface morphology due to strong aggregation. Due to the aggregation, the EPOSS film had shorter d-spacing (d1) than the EPSQ film in XRD analysis. In pencil hardness and nanoindentation analysis, EPSQ film showed higher hardness than the EPOSS film due to regular double-stranded structure. In addition, in the in-folding (r = 0.5 mm) and out-folding (r = 5 mm) tests, the EPSQ film did not crack unlike the EPOSS coated film.


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 631
Author(s):  
Narges Shaabani ◽  
Nora W. C. Chan ◽  
Abebaw B. Jemere

A molecularly imprinted sol-gel is reported for selective and sensitive electrochemical determination of the drug naloxone (NLX). The sensor was developed by combining molecular imprinting and sol-gel techniques and electrochemically grafting the sol solution onto a functionalized multiwall carbon nanotube modified indium-tin oxide (ITO) electrode. The sol-gel layer was obtained from acid catalyzed hydrolysis and condensation of a solution composed of triethoxyphenylsilane (TEPS) and tetraethoxysilane (TES). The fabrication, structure and properties of the sensing material were characterized via scanning electron microscopy, spectroscopy and electrochemical techniques. Parameters affecting the sensor’s performance were evaluated and optimized. A sensor fabricated under the optimized conditions responded linearly between 0.0 µM and 12 µM NLX, with a detection limit of 0.02 µM. The sensor also showed good run-to-run repeatability and batch-to-batch performance reproducibility with relative standard deviations (RSD) of 2.5–7.8% (n = 3) and 9.2% (n = 4), respectively. The developed sensor displayed excellent selectivity towards NLX compared to structurally similar compounds (codeine, fentanyl, naltrexone and noroxymorphone), and was successfully used to measure NLX in synthetic urine samples yielding recoveries greater than 88%.


Author(s):  
Mariele K. Stocker ◽  
Murilo L. Sanson ◽  
Arthur A. Bernardes ◽  
Antonio Marchi Netto ◽  
Rodrigo Brambilla
Keyword(s):  
Sol Gel ◽  

2011 ◽  
Vol 391-392 ◽  
pp. 1296-1301
Author(s):  
Li Min Xi ◽  
Xin Xin Zhang

The newly sulfated nanosolid superacid TiO2/SO4 prepared by sol-gel method was broadly characterized by acid base titration, XRD and TEM, which identified that the superfine solid TiO2/SO4 showing good dispersibility with average size of 27 nm belongs to kind of crystalline nanoparticles. With the help of the catalyst TiO2/SO4, the optimal reaction condition for direct transformation of pyrazole and nitrosonitric acid into 3, 5-Dinitropyrazole was n (pyrazol)=0.10 mol, m (TiO2/SO4 )=1.5g, V(n-octannol)=90mL, and V(nitrosonitric acid)=50mL. Moreover, the optimal yield of the catalytic reaction reached up to 59.4% when the reaction time is 7 hours. The nanosolid superacid catalyst is still of high activity after regenerating eight times by calcination at 600。C.


1999 ◽  
Vol 576 ◽  
Author(s):  
Wenxiu Que ◽  
Y. Zhou ◽  
Y. L. Lam ◽  
Y. C. Chan ◽  
S. D. Cheng ◽  
...  

ABSTRACTWe report the preparation of sol-gel waveguide films based on a newly developed recipe to incorporate organic molecules into the inorganic sol-gel glass matrix. The film was derived from a sol that has a higher titanium content in an organically modified silane (ORMOSIL), namely, ÿ-Glycidoxypropyltrimethoxysilane. We have shown that using spin-coating and low temperature baking, a single coating layer can have a thickness of more than 1.5 μm. When such a single layer film is deposited on a microscope glass slide or a piece of silicon with a buffercladding layer, it is able to support the guiding of optical waves. We have characterized the film using scanning electron microscopy, atomic force microscopy, X-ray diffractometry, thermal gravimetric analysis. differential thermal analysis and Fourier transform infrared spectroscopy and have studied the properties of the waveguide film, including the microstructural properties. the chemical bonding properties, and the optical properties. Based on these experimental results, we found that a heat-treatment at a temperature slightly below 200°C is necessary to attain a dense pore-free film. It has also been noted that a purely inorganic and crack-free silica-titania film can be obtained after baking the titania-ORMOSIL composite film at 500°C or higher.


Author(s):  
Petr Dzik ◽  
Magdalena Morozová ◽  
Petr Klusoň ◽  
Michal Veselý

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.


Wear ◽  
2019 ◽  
Vol 418-419 ◽  
pp. 151-159 ◽  
Author(s):  
Juan F. Gonzalez-Martinez ◽  
Erum Kakar ◽  
Stefan Erkselius ◽  
Nicola Rehnberg ◽  
Javier Sotres

2010 ◽  
Vol 1278 ◽  
Author(s):  
L.L. Díaz-Flores ◽  
A. S. López Rodríguez ◽  
P. SifuentesGallardo ◽  
M.A. Hernàndez Rivera ◽  
M.a Garnica Romo ◽  
...  

AbstractThis work is about the production of hybrid coatings of the system SiO2-PMMA (PMMA, polymethylmethacrylate). These materials have interesting mechanical and chemical properties useful for anticorrosive and wear resistance applications. SiO2-PMMA hybrids were obtained by the sol-gel traditional process, using tetraethylorthosilicate (TEOS) and methylmethacrylate (MMA) by Aldrich Co, as starting reagents. The SiO2:PMMA ratio was varied from 0:1 to about 1:1 at air atmosphere deposition. The coatings were obtained on acrylic sheets and silicon wafers. A diversity of coatings with chemical composition ranging from SiO2 and PMMA to obtain the SiO2-PMMA hybrids were obtained. Infrared (IR) and atomic force microscopy (AFM), were performed to determinate structural and morphological behavior.


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