scholarly journals Optical and Physical Properties of Methyltrimethoxysilane Transparent Film Incorporated with Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
W. Ahliah Ismail ◽  
Zainal Abidin Ali ◽  
R. Puteh

Methyltrimethoxysilane has been used as a base in the formation of transparent sol-gel coatings on glass substrates. Several types of alcohol were used as solvents in order to obtain the highest transparency and scratch hardness of the film. The coating cures at room temperature (26∘C). The clarity of the coated film on the glass substrate was measured using haze meter. The best formulation based on the lowest haze values and light diffusion is the ratio of 1 : 1 trimethoxy silane to N-propanol. The haze value obtained for this system is 0.86, and the light diffusion was measured at 0.77%. Tack-free time and hardness were within acceptable value. Nanoparticles of silver, zinc oxide, and titanium dioxide were incorporated into the coating system from 0.5% to 2.5% by weight, and the haze values of the dried film were measured. The highest transparency was obtained from the samples that were mixed with 0.5% silver. The haze value for this sample is of 0.5.

2013 ◽  
Vol 678 ◽  
pp. 80-85 ◽  
Author(s):  
Krishnasamy Sakthivel ◽  
T. Venkatachalam

Thin films of TiO2 have been deposited on well cleaned glass substrates by Sol-Gel dip-drive coating technique. The films have been prepared at three different pH values (1, 3.5 & 9) of Sol and annealed in muffle furnace at 550°C for one hour and are allowed to cool to room temperature. The films were characterized by XRD, EDAX, SEM and UV-Vis Spectrophotometer. The as deposited films were found to be amorphous in nature. The annealed films exhibit anatase in crystalline structure. The EDAX results have shown that all the films are maintained with TiO2 in composition. The XRD results reveal that they are nano-crystalline in nature and the crystalline nature increases with pH of the Sol. The transmittance and absorbance spectra have shown that the films are transparent and band gap of the films are of the order of 3.2eV. The ab initio studies of TiO2 (using GGA) was performed with Vienna ab initio Simulation package and the band structure and effective masses of the electrons and holes were determined.


2010 ◽  
Vol 447-448 ◽  
pp. 740-744 ◽  
Author(s):  
Xiao Zhang ◽  
Min Qian ◽  
Yu Chan Liu ◽  
Hong Xie

In this paper we report the fabrication of hydrophobic hard coatings using sol-gel processing and cured at room temperature by an ammonia-assisted process. The coating thickness can be tuned from several hundreds of nanometer to several microns. These coatings show both high transparency (better than PMMA or glass substrates) and high hardness (pencil hardness 2H-4H on PMMA). The coatings are very smooth with surface roughness Ra less than 2 nm for coatings with different thicknesses from 200 nm to 2 m. The water contact angle (WCA) of the coating is about 115 to 120o and the sliding angle for a 20 l water drop is less than 10o. The advantage of this process is the ease for larger area application and especially suitable for plastic surface treatment due to the low temperature curing process.


2009 ◽  
Vol 423 ◽  
pp. 161-165 ◽  
Author(s):  
Aziz Rebati ◽  
Manuel Piñero ◽  
Nicolás de la Rosa-Fox ◽  
Luis Maria Esquivias Fedriani

The mechanical properties of black thin film on glass substrates and metallic, obtained from the synthesis of organic-inorganic silica hybrids via sol-gel are described. Hybrid silica-based coatings with tetraethoxysilane (TEOS), methyltrietoxysilane (MTES), polyurethane (PU) and commercial silica colloidal solution (Ludox HS30) as precursors, were used. The procedure is divided in the following three steps: 1) obtaining homogenous and stable solutions of different organic silica-polymer composition, 2) aggregation of the black pigment with the formulate FeMnOx, 3) Coating substrates by both dip-coating and aerograph airbrush, at room temperature. The films obtained were characterized by SEM, AFM and nano-indentation. The coatings of the Ludox-MTES-PU/FeMnOx system showed the better characteristics concerning the morphology and the adhesion to the glass and metallic copper substrates


2016 ◽  
Vol 721 ◽  
pp. 394-398 ◽  
Author(s):  
Anzelms Zukuls ◽  
Gundars Mezinskis

Fe2O3–TiO2 coatings were successfully prepared on glass slide substrates using sol–gel method for wettability applications. The microstructure and surface properties of the coatings were extensively characterized by using X-ray diffractometry (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Different solutions were prepared by adding distilled water to sol solution. Glass substrates were coated by solutions of Ti-alkoxide, Fe-chloride hexahydrate, ethylene glycol, acetic acid, isopropanol and glycerol. The obtained gel films were dried at room temperature for 15 min in air. The oxide thin films were annealed at 500 ºC for 1h. The influence of distilled water concentration and withdraw speed on contact angle of the films was established. In addition, XRD results revealed that Fe2O3–TiO2 films composed of anatase, rutile, brookite and hematite phases. The purpose of this contribution was the investigation of different preparation parameters during the synthesis of iron oxide rich Fe2O3–TiO2 thin hydrophobic films on glass substrate. SEM and AFM observations revealed leaf-like structure formation on a coating surface.


2008 ◽  
Vol 8 (12) ◽  
pp. 6491-6496
Author(s):  
Jorge Garcia-Macedo ◽  
Guadalupe Valverde-Aguilar ◽  
Raúl W. Gómez ◽  
José L. Pérez-Mazariego ◽  
Vivianne Marquina

Sol–gel thin films containing Fe2O3 were deposited onto glass substrates by the dip-coating method at room temperature. Fe2O3 enriched with the isotope 57Fe was embedded in two kinds of matrices: zinc oxide (ZnO) and silica (SiO2). X-ray diffraction (XRD) was used for morphology and structure determination of the nanostructures and showed that the ZnO exhibit a wurtzite form when the film is annealed at 450 °C for 20 min. SiO2 thin films at C16H33PEO20:Fe2O3 = 1:2.7 × 10−1 molar concentration exhibit a hexagonal nanophase produced by the diblock copolymer Brij58 (C16H33PEO20). Optical absorption and infrared spectroscopy techniques were used to evaluate the optical quality of the films. In order to determine if the Fe2O3 was incorporated into the matrices, room temperature Mössbauer spectra of both samples were obtained. In both cases the hematite spectrum was obtained, corroborating that the incorporation of the Fe2O3 to the matrices was done without chemical reaction whatsoever.


2001 ◽  
Vol 15 (17n19) ◽  
pp. 813-816 ◽  
Author(s):  
A. Conde-Gallardo ◽  
M. García-Rocha ◽  
I. Hernández Calderón ◽  
R. Palomino-Merino

Results on the fabrication and characterisation of thin films of the novel host, titania ( TiO 2), for the Tb 3+ activator ion are reported. The titania films were produced by the sol-gel process at room temperature using the dip coating method and deposited on silicon and corning glass substrates. It is shown that a different surface morphology is developed for the TiO 2:Tb films deposited on different substrates. When enough amount of Tb is incorporated and, a He-Cd 325 nm photoexcitation is used as excitation line, the films show green photoluminescence (PL) signal associated with the 5 D 4→7 F j transition of the electronic structure of Tb 3+ plus an broad band due to matrix's defects. The PL emission has better characteristics for the films deposited on silicon wafers.


1993 ◽  
Vol 329 ◽  
Author(s):  
Michael Canva ◽  
Patrick Georges ◽  
Jean-Fran^ois Perelgritz ◽  
Alain Brun ◽  
Fréddric Chaput ◽  
...  

AbstractPhotoresistant laser dyes were trapped in silica based xerogel host matrices to obtain solid state tunable lasers. For this purpose very dense xerogel samples with improved chemical and physical properties were prepared at room temperature by the sol-gel technology. The as-prepared materials were polished to obtain optical quality surfaces and were used as new lasing media.Lasing action of such different dyes as rhodamine, perylene and pyrromethene doping dense sol-gel matrices was demonstrated. Efficiencies of 30 % or lifetimes of more than 100,000 shots were achieved with different new ≤dye dopant/host matrix≥ couples. Their different performances are reviewed and discussed.


Author(s):  
Mohsen Nikoorazm ◽  
Maryam Khanmoradi ◽  
Masoumeh Sayadian

Introduction:: MCM-41 was synthesized using the sol-gel method. Then two new transition metal complexes of Nickel (II) and Vanadium (IV), were synthesized by immobilization of adenine (6-aminopurine) into MCM-41 mesoporous. The compounds have been characterized by XRD, TGA, SEM, AAS and FT-IR spectral studies. Using these catalysts provided an efficient and enantioselective procedure for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using hydrogen peroxide at room temperature. Materials and Methods:: To a solution of sulfide or thiol (1 mmol) and H2O2 (5 mmol), a determined amount of the catalyst was added. The reaction mixture was stirred at room temperature for the specific time under solvent free conditions. The progress of the reaction was monitored by TLC using n-hexane: acetone (8:2). Afterwards, the catalyst was removed from the reaction mixture by centrifugation and, then, washed with dichloromethane in order to give the pure products. Results:: All the products were obtained in excellent yields and short reaction times indicating the high activity of the synthesized catalysts. Besides, the catalysts can be recovered and reused for several runs without significant loss in their catalytic activity. Conclusion:: These catalytic systems furnish the products very quickly with excellent yields and VO-6AP-MCM-41 shows high catalytic activity compared to Ni-6AP-MCM-41.


Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.


2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.


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