scholarly journals Engineering of Ultra-Violet Reflectors by varying Alternate Layers of Titania/Silica for Harmful UV-Protection

2021 ◽  
Author(s):  
R.S. Dubey ◽  
◽  
Yepuri Venkatesh ◽  
Keyword(s):  
Sol Gel ◽  
Ultra Violet ◽  
Photonic Devices ◽  
Uv Protection ◽  
Center Wavelength ◽  
Vis Spectroscopy ◽  
Coating Method ◽  
Index Contrast ◽  
Optical Reflectors ◽  
Protection Coating

The primary requisite of engineering optical/photonic devices is either for scaling or altering the properties. Here, we present the engineering of ultra-violet (UV) reflectors made up of alternate layers of titania (TiO2) and silica (SiO2) by using the sol-gel spin coating method. The choice of these two materials is appropriate to realize the optical reflectors due to their large refractive index contrast. The formation of multilayer films of TiO2 and SiO2 are studied by field-emission scanning electron microscopy (FESEM), while UV-vis spectroscopy measurement is performed to study the reflectance. By varying the number of TiO2/SiO2 stacks, we have achieved the maximum reflectance within the UV region at center wavelength of 335 nm, 358 nm, and 367 nm corresponding to the 3, 6, and 9 stacks-based reflectors. Finally, we summarize that these reflectors prohibit the propagation of ultraviolet light, and therefore, they are promising as UV protection coating.

scholarly journals Síntesis y caracterización de un compuesto semiconductor NiO-ZnO dopado con nanopartículas de Au por el método sol-gel para aplicación como sensores de gas

2019 ◽  
pp. 5-10 ◽  
Keyword(s):  
Spin Coating ◽  
Gas Sensing ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Silicon Substrates ◽  
Chloroauric Acid ◽  
Porous Films ◽  
Nickel Acetate Tetrahydrate ◽  
Vis Spectroscopy ◽  
Coating Method

Síntesis y caracterización de un compuesto semiconductor NiO-ZnO dopado con nanopartículas de Au por el método sol-gel para aplicación como sensores de gas Alex Díaz, Dionicio Otiniano, E. Della Gaspera, Alessandro Martucci Departamento de Ingeniería de Materiales, Universidad Nacional de Trujillo-Perú Dipartimento d’Ingegneria Meccanica – Settore Materiali, Universita di Padova, 35131 Padova-Italia DOI: https://doi.org/10.33017/RevECIPeru2012.0002/ RESUMEN Láminas porosas de un compuesto semiconductor formado por NiO-ZnO (%mol) dopado con nanopartículas de Au (3% mol) fueron preparados por el método sol-gel usando acetato de níquel tetrahidratado (NiC4H6O4.4H2O) y acetato de zinc dihidratado (C4H6O4Zn.2H2O) como precursores, metanol (CH6OH) y etanol (C2H6O) como solventes, monoetanolamina (C2H7NO) y dietanolamina (C4H11NO2) como ligantes funcionales, y ácido cloroaúrico HAuCl4 como precursor. Las muestras se caracterizaron por espectroscopias Infrarrojo (IR), ultravioleta (UV-VIS), microscopía SEM, difracción de rayos X (XRD), y ensayos de sensores gaseosos. Las muestras semiconductoras fueron depositadas sobre substratos de silicio por el método de spin-coating a 2000 rpm, posteriormente fueron tratadas a 500 y 600 ºC. Los efectos de las composiciones de NiO-ZnO y el porcentaje de dopaje también se discuten en este argumento. El espesor de la capa fue determinado por elipsometria aproximado a 75 nm. Estos compuestos fueron ensayados para sensores gaseosos de H2 y CO (1% V/V) a 300ºC, demostrando óptimos resultados para el H2, pero no así para el CO. Descriptores: NiO, ZnO, semiconductores, sensor gaseoso. ABSTRACT Porous films formed by a semiconductor ZnO-NiO (% mol) doped with Au nanoparticles (3% mol) were prepared by sol-gel method using nickel acetate tetrahydrate (NiC4H6O4.4H2O) and zinc acetate dihydrate (C4H6O4Zn.2H2O) as precursors, methanol (CH6OH) and ethanol (C2H6O) as solvents, monoethanolamine (C2H7NO) and diethanolamine (C4H11NO2) as functional chelants, and chloroauric acid (HAuCl4) as gold precursor. The samples were characterized by infrared (IR) and ultraviolet (UV-VIS) spectroscopy, microscopy SEM, X-ray diffraction (XRD) and gas sensing tests. The semiconductor samples were deposited on silicon substrates by spin-coating method at 2000 rpm, subsequently annealing at 500 and 600 °C. The effects of the compositions of NiO-ZnO and the percentage of doping are also discussed. The layer thickness was determined by ellipsometry in approximately 75 nm. These compounds were tested for gas sensors for H2 and CO (1% V/V) at 300 °C, showing excellent results for H2, but not for the CO. Keywords: NiO, ZnO, semiconductors, gas sensor.

scholarly journals Comparative study of absorption band edge tailoring by cationic and anionic doping in TiO2

2018 ◽  
Vol 36 (3) ◽  
pp. 435-438
Author(s):  
Arpit Swarup Mathur ◽  
Praveen Kumar ◽  
B.P. Singh
Keyword(s):  
Titanium Dioxide ◽  
Absorption Band ◽  
Sol Gel ◽  
Visible Region ◽  
Solar Spectrum ◽  
Band Edge ◽  
Absorption Band Edge ◽  
Vis Spectroscopy ◽  
Coating Method ◽  
Nanocrystalline Titanium

AbstractTitanium dioxide (TiO2) is one of the most favored metal oxide semiconductors for the use as photoanode in photoelectrochemical cells (PEC) splitting the water into hydrogen and oxygen. However, the major impediment is its large bandgap that limits its utilization as photoanode. Doping has evolved as an effective strategy for tailoring optical and electronic properties of TiO2. This paper describes the synthesis of undoped as well as iron (Fe, cationic) and nitrogen (N, anionic) doped nanocrystalline titanium dioxide by sol-gel spin coating method for solar energy absorption in the visible region. All the prepared thin films were characterized by X-ray diffraction and UV-Vis spectroscopy. Doping of both Fe and N into TiO2 resulted in a shift of absorption band edge towards the visible region of solar spectrum.

Spin Coated CuO with Different Additives (PEG) Value Thin Film: Physical, Structural, Optical and Electrical Characteristics of CuO/PEG

2020 ◽  
Vol 301 ◽  
pp. 43-51
Author(s):  
Rohanieza Abdul Rahman ◽  
Muhammad AlHadi Zulkefle ◽  
Nur Syaza Muhammad Kamar ◽  
Zulfakri Mohamad ◽  
Sukreen Hana Herman ◽  
...  
Keyword(s):  
Thin Film ◽  
Indium Tin Oxide ◽  
Sol Gel ◽  
Ultra Violet ◽  
Electrical Characteristics ◽  
X Ray Diffraction ◽  
Current Voltage ◽  
Coating Method ◽  
Materials Used ◽  
Change Material

This study presents an investigation on copper oxide (CuO) composited with polyethylene glycol (PEG) thin film. The main objective for this compositing thin film is to explore and determine the characteristic of the thin film when the value of PEG is varied. In this study, PEG plays a role as phase change material (PCM), where this type of material has the capability to absorb and release heat based on its surrounding condition. Due to this characteristic, the amount of PEG is vary from 0.5, 1.0, 1.5 and 2.0 ml to confirm its influence towards CuO thin film. As for comparison, CuO thin film without PEG is also fabricated. Both of the materials used were prepared using sol-gel route and deposited onto indium tin oxide (ITO) substrate using spin coating method. The influences of the PEG values on CuO thin film were investigated using field emission scanning electron microscope (FESEM), x-ray diffraction (XRD), ultra-violet visible microscope (UV-Vis), and current-voltage (IV) measurement. Based on the investigation conducted, the characteristics of CuO thin film produced in this study are affected with the different value of PEG.

scholarly journals Visible Region Response of Cobalt Doped TiO2 via Sol Gel Technique

2018 ◽  
Vol 26 (8) ◽  
pp. 240-244
Author(s):  
AbdulKareem AbdulHusssein Kareem Al-Khafajia ◽  
AbdulNaser Hasan Al-Zurfy
Keyword(s):  
Sol Gel ◽  
Visible Region ◽  
Dip Coating ◽  
Pure Tio2 ◽  
Cobalt Ions ◽  
Force Microscopy ◽  
Vis Spectroscopy ◽  
Coating Method ◽  
Gel Technique ◽  
Dip Coating Method

TiO2 nanoparticles were prepared via sol-gel technique and then doped with cobalt ions to form TiO2 doped cobalt sol. Thin films were prepared from this sol using dip coating method and underwent calcination at a temperature of 550 C.The films were characterized by UV–Vis spectroscopy, X-ray diffraction (XRD), and atomic force microscopy (AFM). The UV–Vis. Absorption spectra show a redshift, which indicates that TiO2 doped cobalt will respond to the visible region of the spectrum rather than UV- region for pure TiO2.  

UV-Vis and Raman Characterization Multilayer of PMMA Films Spin Coated onto Substrate by Sol-Gel Spin-Coating Method

2015 ◽  
Vol 1109 ◽  
pp. 613-616 ◽  
Author(s):  
Aadila Aziz ◽  
N.A.M. Asib ◽  
A.N. Afaah ◽  
Ruziana Mohamed ◽  
M. Rusop ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Spin Coating ◽  
Sol Gel ◽  
Homogeneous Solution ◽  
Pmma Film ◽  
Spin Coating Method ◽  
Vis Spectroscopy ◽  
Coating Method ◽  
Size Of Particles ◽  
Raman Characterization

Different layers of PMMA spin coated onto substrate were successful prepared by sol-gel spin-coating method. PMMA was dissolved in toluene solvent and was aged for 24 hours to produce the homogeneous solution. The films were then characterized by Raman Spectroscopy and Ultraviolet-Visible (UV-Vis) spectroscopy. Raman spectroscopy studied reveals the 7 layers of PMMA film exhibit the strong and sharp intense peak at observed band around 810 cm-1 that is due to the symmetric CC4 stretching. The UV-Vis measurement present 7 layers of PMMA film have good absorption due to the small size of particles and uniform surface of the film.

Silica Interlayer Formation of Mesoporous Silica Coatings on Hydroxyapatite Granules

2017 ◽  
Vol 758 ◽  
pp. 19-23 ◽  
Author(s):  
Yoshiyuki Yokogawa ◽  
Atsumasa Shishido ◽  
K. Hiroyasu
Keyword(s):  
Mesoporous Silica ◽  
Magnetron Sputtering ◽  
Protein Adsorption ◽  
Adsorption Capacity ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Coatings ◽  
Vis Spectroscopy ◽  
Coating Method ◽  
Dip Coating Method

Mesoporous silica (MPS) coatings on hydroxyapatite (HAp) granules and their protein adsorptive capabilities were studied. MPS particles were coated on HAp granules using a dip-coating method, but the HAp granules were not totally covered by the MPS particles. A silica interlayer was formed on the HAp granules via magnetron sputtering or the sol-gel method prior to the coating of the MPS. The HAp granules coated with the silica interlayer were fully covered by the MPS particles. An silica interlayer may offer bonding between the HAp granules and MPS coating. The adsorption of protein on the MPS-coated HAp granules was evaluated by UV-VIS spectroscopy. The adsorption capacity of protein on the HAp granules was improved by the MPS coatings on the HAp granules, and that of the HAp granules coated with the silica interlayer showed a higher protein adsorption capacity.

Nanocrystalline Thin Films TiO2 Prepared by Different Concentration of Organic Acid and their Photocatalytic Activity

2011 ◽  
Vol 233-235 ◽  
pp. 363-368
Author(s):  
Nitikarn Fangern ◽  
Sudjit Sanguanruang ◽  
Chamorn Chawengkijwanich
Keyword(s):  
Thin Films ◽  
Surface Area ◽  
Anatase Phase ◽  
Sol Gel ◽  
Dip Coating ◽  
Bet Surface Area ◽  
Glass Substrates ◽  
Vis Spectroscopy ◽  
Coating Method ◽  
Dip Coating Method

In this work, TiO2thin films were deposited on borosilicate glass substrates by sol-gel dip coating method and calcined at 500 °C for 15 min(heating rate3°C/min). The TiO2sol was prepared by fixing concentration of titaniumtetraisopropoxide(TTIP), TritonX-100 surfactant, ethanol and conc hydrochloric acid but amounts of acetyl acetone (Acac ) were various as 4, 6 and 8 mole respectively. After calcination process, all the TiO2thin films were homogeneous and transparent. Several techniques , such as X-ray diffraction (XRD), UV-Vis spectroscopy, Environment Scanning Electron Microscope (E-SEM), atomic force microscopy (AFM) and BET surface area analysis were used to characterize the prepared TiO2thin film. Spectra of XRD showed that the crystal structure was anatase phase with the crystal sizes of 9.05 – 12.57 nm. According to BET surface area analysis, the surface area , pore volume and pore size of TiO2were in the range of 66.35-82.53 m2/gm , 0.1194-0.1301 cm3/g and 57-71 A0respectively. The photodegradation of Reactive Blue 19 by the prepared TiO2thin films showed decomposition rate of 97.58% , 95.03 % and 94.48% for the thin films prepared by using 4, 6 and 8 mole AcAc respectively.

Porous Gel Coatings Obtained by Phase Separation in ORMOSIL System

2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai
Keyword(s):  
Phase Separation ◽  
Reaction Time ◽  
Volume Fraction ◽  
Sol Gel ◽  
Reaction Times ◽  
Dip Coating ◽  
Coating Solution ◽  
Coating Method ◽  
Gel Phase ◽  
Dip Coating Method

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.

Exploring the characteristics of the nickel oxide nanoparticles via Sol - gel method

2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Jothi M ◽  
Sowmiya K
Keyword(s):  
Nickel Oxide ◽  
Ph Value ◽  
Lattice Structure ◽  
Sol Gel ◽  
Systematic Change ◽  
Average Crystalline Size ◽  
Nio Nanoparticles ◽  
Nickel Oxide Nanoparticles ◽  
X Ray ◽  
Vis Spectroscopy

Nickel Oxide (NiO) is an important transition metal oxide with cubic lattice structure. NiO is thermally stable that is suitable for tremendous applications in the field of optic, ceramic,glass, electro-chromic coatings, plastics, textiles, nanowires, nanofibers, electronics,energy technology, bio-medicine, magnetism and so on. In this present study, NiO nanoparticles were successfully synthesized by sol-gel technique. Nano-sols were prepared by dissolving Nickel-Chloride [NiCl2.6H2O] in NaOH solvent and were converted into nano structured gel on precipitation. A systematic change in preparation parameters like calcination temperature, time, pH value has been noticed in order to predict the influence on crystallite size. Then the prepared samples were characterized by the X-ray Diffraction Spectroscopic (XRD), UV-VIS Spectroscopy, Fourier Transform Infra-Red Spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDX), Scanning Electron Microscopy (SEM) and Particle Size Analyzer (PSA). From XRD, the average crystalline-size has been calculated by Debye-Scherrer Equation and it was found to be 12.17 nm and the band gap energy of Nickel oxide (NiO) from UV studies reveals around 3.85 eV. Further, EDX and FTIR studies, confirm the presences of NiO nanoparticles. The SEM study exhibits the spherical like morphology of Nickel oxide (NiO). Further from PSA, the mean value of NiO nanoparticles has been determined.

Valence state and magnetism of Mn-doped PbPdO 2 nanograin film synthesized by sol-gel spin-coating method

2017 ◽  
Vol 623 ◽  
pp. 14-18 ◽  
Author(s):  
Fenglin Tang ◽  
Chao Mei ◽  
Peiyu Chuang ◽  
Tingting Song ◽  
Hailin Su ◽  
...  
Keyword(s):  
Spin Coating ◽  
Valence State ◽  
Sol Gel ◽  
Spin Coating Method ◽  
Coating Method ◽  
Mn Doped
Sign in / Sign up

Export Citation Format

Share Document