scholarly journals Preparation of High Hardness Transparent Coating with Controllable Refractive Index by Sol-Gel Technology

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 690
Author(s):  
Xiaolin Liu ◽  
Yansong Wang ◽  
Tao Bai
Keyword(s):  
Refractive Index ◽  
Composite Coatings ◽  
Condensation Reaction ◽  
Sol Gel ◽  
High Hardness ◽  
Light Transmittance ◽  
Friction Resistance ◽  
Inorganic Coatings ◽  
Transparent Coating ◽  
Zro2 Sol

SiO2/ZrO2 and SiO2/ZrO2/Al2O3 composite organic–inorganic coatings were prepared by the sol-gel technology. The structure of the coating was characterized by IR, particle size analyzer, SEM, and AFM, respectively. The results showed that ZrO2, SiO2 (inorganic component), and siloxane had undergone a hydrolytic condensation reaction, and the composite organic–inorganic coatings were formed with -O-M-O- (M is Si, Zr) as molecular skeleton network structure. Adding an appropriate ratio of ZrO2 sol, no agglomeration and phase separation occurred, which could significantly improve the refractive index, hardness, and light transmittance of the coatings. Al2O3 sol could greatly improve the friction resistance of the composite organic–inorganic coatings, and the Bayer ratio of the composite coatings could reach 7.86. By adjusting the proportioning of composite sol solution, the refractive index of the composite transparent coatings could be controlled from 1.52 to 1.65.

scholarly journals Silica Sol-gel Coatings with Improved Light Transmittance and Stability

2017 ◽  
Author(s):  
Lenke Kócs ◽  
Emőke Albert ◽  
Borbála Tegze ◽  
Márta Kabai-Faix ◽  
Csaba Major ◽  
...  
Keyword(s):  
Refractive Index ◽  
Sol Gel ◽  
Temporal Stability ◽  
Storage Period ◽  
Dip Coating ◽  
Silica Sol ◽  
Model Systems ◽  
Light Transmittance ◽  
Silica Coatings ◽  
Glass Substrates

Silica sol-gel coatings on different substrate materials and their use as model systems have been studied. Mesoporous silica coatings with thicknesses of 85 - 135 nm and porosity of 18 ˗ 37% were prepared by dip-coating on polycarbonate and glass substrates. In order to eliminate the shrinkage of the porous structure acid or base vapour treatment was applied. Thickness and refractive index of the coatings were determined by analysing the transmittance spectra of the samples. Ellipsometric porosimetry measurements were carried out to determine the porosity, pore radius distribution, thickness and refractive index. The thickness of the samples was further confirmed by scanning electron microscopy. The adsorption capacity of the porous coatings was also studied by dye impregnation tests. The temporal stability of the samples was investigated by UV-Vis spectrometry and it was found that the advantageous optical properties (Tmax = 98 – 99%) of the samples remained constant even after a 1 year storage period.

Nanostructured hybrid materials obtained by UV curing and sol-gel processes involving alkoxysilane groups

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Ezio Amerio ◽  
Giulio Malucelli ◽  
Marco Sangermano ◽  
Aldo Priola
Keyword(s):  
Coupling Agent ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Uv Curing ◽  
Thermally Induced ◽  
Inorganic Coatings ◽  
Ft Ir ◽  
Ir Analysis ◽  
Degree Of Condensation ◽  
Kinetics Of

AbstractNovel hybrid organic-inorganic coatings were obtained by photopolymerization and subsequent thermally induced condensation through solgel processes. Both radical (methacrylic) and cationic (epoxy) resins were considered as precursors of the organic phase; tetraethoxysilane (TEOS) was the precursor of the inorganic phase. The effect of the presence of a coupling agent was investigated. Real-time FT-IR analysis was used for evaluating the kinetics of photopolymerization. 29Si-NMR spectroscopy was used in order to evaluate the degree of condensation of alkoxysilane groups. The results showed the prevalence of Q3 e T2 structures indicating an incomplete condensation of the alkoxysilane groups. T1 and Q1 signals are not present, thus indicating that for each Si atom, two or more alkoxysilane groups take part to the condensation reaction. FE-SEM analyses evidenced a nanometric organization of the inorganic domains in the polymer matrix. The addition of the coupling agent was found to influence the morphology of the hybrid systems. DMTA and TGA analyses revealed an increase of the Tg values and of the thermal stability by increasing the coupling agent and TEOS content.

Facile Deposition of Zirconia Optical Films Based on the Solvothermal Treatment of Zirconyl Nitrate-Water-Methanol System

2012 ◽  
Vol 217-219 ◽  
pp. 1033-1037
Author(s):  
Li Ping Liang ◽  
Cai Xia Su
Keyword(s):  
Refractive Index ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Reaction Medium ◽  
Volume Ratio ◽  
High Refractive Index ◽  
Hydrodynamic Diameter ◽  
Film Material ◽  
Zirconyl Nitrate ◽  
Optical Films

Zirconia optical films have been facilely deposited based on a modified sol-gel route, which involved solvothermal-treating a mixture of zirconyl nitrate, water, and methanol at 80 °C to produce zirconia-based sols, spin-coating the sols on K9 glass substrates, and then calcining the films at moderate temperatures. The experiments show that, at the proper volume ratio of methanol to water VM/VW(from 40/35 to 70/5), the high deprotonation-condensation reaction rate of the precursor zirconium salt, along with the moderate critical supersaturation level of the reaction medium, give rise to stable and uniform sols comprising particles with mean hydrodynamic diameter of 10-40 nm. This enables rapid deposition of zirconia-based films with a comparatively high refractive index of 1.62 (at 1064 nm). After calcination at 400 °C, the purification and crystallization of film material endow the film with a high refractive index of 1.91 (at 1064 nm).

scholarly journals Manufacture of Contact Lens of Nanoparticle-Doped Polymer Complemented with ZEMAX

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2028
Author(s):  
Lina M. Shaker ◽  
Ahmed A. Al-Amiery ◽  
Abdul Amir H. Kadhum ◽  
Mohd S. Takriff
Keyword(s):  
Contact Lenses ◽  
Titanium Dioxide Nanoparticles ◽  
Optical Design ◽  
Sol Gel ◽  
High Refractive Index ◽  
Light Transmittance ◽  
Great Promise ◽  
Modulation Transfer ◽  
Tio2 Nps ◽  
Molding Method

Many people suffer from myopia or hyperopia due to the refractive errors of the cornea all over the world. The use of high refractive index (RI), Abbe number (νd), and visible light transmittance (T%) polymeric contact lenses (CLs) holds great promise in vision error treatment as an alternative solution to the irreversible laser-assisted in situ keratomileusis (LASIK) surgery. Titanium dioxide nanoparticles (TiO2 NPs) have been suggested as a good candidate to rise the RI and maintain high transparency of a poly(methyl methacrylate) (PMMA)-TiO2 nanocomposite. This work includes a preparation of TiO2 NPs using the sol gel method as well as a synthesis of pure PMMA by free radical polarization and PMMA-TiO2 CLs using a cast molding method of 0.005 and 0.01 w/v concentrations and a study of their effect on the aberrated human eye. ZEMAX optical design software was used for eye modeling based on the Liou and Brennan eye model and then the pure and doped CLs were applied. Ocular performance was evaluated by modulation transfer function (MTF), spot diagram, and image simulation. The used criteria show that the best vision correction was obtained by the CL of higher doping content (p < 0.0001) and that the generated spherical and chromatic aberrations in the eye had been reduced.

Preparation and Characterization of Zn-Containing Hydroxyapatite/TiO2 Composite Coatings on Ti Alloys

2011 ◽  
Vol 685 ◽  
pp. 367-370 ◽  
Author(s):  
Min Qi ◽  
Da Yi Yang ◽  
Jing Ying Zhang ◽  
Hong Jun Ai
Keyword(s):  
Adhesion Strength ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Zn Content ◽  
Micro Arc Oxidation ◽  
Gel Technique ◽  
Bacteria Resistance

In order to improve the osteoblast growth and bacteria resistance, Zn-containing hydroxyapatite (Zn-HA) and titanium oxide (TiO2) composite coatings were prepared to improve binding between coating and Ti substrate. TiO2 film was prepared on the surface of Ti by micro-arc oxidation (MAO) and Zn-HA coating was deposited on TiO2 using sol–gel technique. Phase structure, composition and microstructure of the surface coatings were analyzed by X-ray diffraction (XRD) and Energy Dispersive Spectrometer (EDS), respectively. The adhesion strength between the coatings with different Zn content was measured by tensile testing. The results showed that there was no significant influence of Zn content on adhesion strength between coating and Ti substrate.

Synthesis, Characterization, and Microwave Absorption Properties of SrFe12O19 Ferrites and FeNi3 Nanoplatelets Composites

2010 ◽  
Vol 148-149 ◽  
pp. 893-896 ◽  
Author(s):  
Ze Yang Zhang ◽  
Xiang Xuan Liu ◽  
You Peng Wu
Keyword(s):  
Electron Microscopy ◽  
Microwave Absorption ◽  
Composite Coatings ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
Filling Fraction ◽  
Microwave Absorption Properties ◽  
Phase Reduction ◽  
Transmission Electron

M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were successfully prepared by the sol-gel method and solution phase reduction method, respectively. The crystalline and morphology of particles were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The composite coatings with SrFe12O19 ferrites and FeNi3 nanoplatelets in polyvinylchloride matrix were prepared. The microwave absorption properties of these coatings were investigated in 2-18GHz frequency range. The results showed that the M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were obtained and they presented irregular sheet shapes. With the increase of the coating thickness, the absorbing peak value moves to the lower frequency. The absorbing peak values of the wave increase along with the increasing of the content of FeNi3 nanoplatelets filling fraction. When 40% SrFe12O19 ferrites is doped with 20% mass fraction FeNi3 nanoplatelets to prepare composite with 1.5mm thickness, the maximum reflection loss is -24.8 dB at 7.9GHz and the -10 dB bandwidth reaches 3.2GHz.

Thermally Sprayed Quasicrystal Composite Coatings for Bearings and Other Friction Threaded Applications

2000 ◽  
Author(s):  
E. Lugscheider ◽  
C. Herbst-Dederichs ◽  
A. Reimann
Keyword(s):  
Composite Coatings ◽  
High Hardness ◽  
Atmospheric Plasma ◽  
Ductile Material ◽  
Metallurgical Analysis ◽  
The Matrix ◽  
Material Forming ◽  
Alloy Properties ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Abstract Quasicrystalline phases improve many alloy properties such as thermomechanical stability, thermal and electrical conductivity, and tribological performance. High hardness, however, is accompanied by brittleness, an undesired property in many applications. Reduced brittleness can be achieved by embedding quasicrystalline phases in a more ductile material, forming a metal-matrix composite that retains some quasicrystalline properties. This study evaluates thermally sprayed coatings made from different compositions of such composites. The coatings assessed were produced by arc-wire, HVOF, and atmospheric plasma spraying using various forms of feed material, including blended, agglomerated, chemical encased, and attrition-milled powders and filled wires. The investigation involved metallurgical analysis, proving the existence of quasicrystal content and assessing the matrix phase, and tests showing how sliding wear is influenced by the composition of quasicrystalline phases.

scholarly journals Mode Sensitivity Exploration of Silica–Titania Waveguide for Refractive Index Sensing Applications

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7452
Author(s):  
Muhammad A. Butt ◽  
Andrzej Kaźmierczak ◽  
Cuma Tyszkiewicz ◽  
Paweł Karasiński ◽  
Ryszard Piramidowicz
Keyword(s):  
Refractive Index ◽  
High Performance ◽  
Near Infrared ◽  
Sol Gel ◽  
Cost Effective ◽  
Dip Coating ◽  
Infrared Wavelength ◽  
Refractive Index Sensing ◽  
Sensing Applications ◽  
Coating Method

In this paper, a novel and cost-effective photonic platform based on silica–titania material is discussed. The silica–titania thin films were grown utilizing the sol–gel dip-coating method and characterized with the help of the prism-insertion technique. Afterwards, the mode sensitivity analysis of the silica–titania ridge waveguide is investigated via the finite element method. Silica–titania waveguide systems are highly attractive due to their ease of development, low fabrication cost, low propagation losses and operation in both visible and near-infrared wavelength ranges. Finally, a ring resonator (RR) sensor device was modelled for refractive index sensing applications, offering a sensitivity of 230 nm/RIU, a figure of merit (FOM) of 418.2 RIU−1, and Q-factor of 2247.5 at the improved geometric parameters. We believe that the abovementioned integrated photonics platform is highly suitable for high-performance and economically reasonable optical sensing devices.

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