Sol–gel derived copper-doped silica glass as a sensitive material for X-ray beam dosimetry

2016 ◽  
Vol 51 ◽  
pp. 104-109 ◽  
Author(s):  
Bruno Capoen ◽  
Hicham El Hamzaoui ◽  
Mohamed Bouazaoui ◽  
Youcef Ouerdane ◽  
Aziz Boukenter ◽  
...  
Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2611
Author(s):  
Jessica Bahout ◽  
Youcef Ouerdane ◽  
Hicham El Hamzaoui ◽  
Géraud Bouwmans ◽  
Mohamed Bouazaoui ◽  
...  

Optically activated glasses are essential to the development of new radiation detection systems. In this study, a bulk glassy rod co-doped with Cu and Ce ions, was prepared via the sol-gel technique and was drawn at about 2000 °C into a cylindrical capillary rod to evaluate its optical and radioluminescence properties. The sample showed optical absorption and photoluminescence (PL) bands attributed to Cu+ and Ce3+ ions. The presence of these two ions inside the host silica glass matrix was also confirmed using PL kinetics measurements. The X-ray dose rate was remotely monitored via the radioluminescence (RL) signal emitted by the Cu/Ce scintillating sensor. In order to transport the optical signal from the irradiation zone to the detection located in the instrumentation zone, an optical transport fiber was spliced to the sample under test. This RL signal exhibited a linear behavior regarding the dose rate in the range at least between 1.1 mGy(SiO2)/s and 34 Gy(SiO2)/s. In addition, a spectroscopic analysis of this RL signal at different dose rates revealed that the same energy levels attributed to Cu+ and Ce3+ ions are involved in both the RL mechanism and the PL phenomenon. Moreover, integrated intensities of the RL sub-bands related to both Cu+ and Ce3+ ions depend linearly on the dose rate at least in the investigated range from 102 mGy(SiO2)/s up to 4725 mGy(SiO2)/s. The presence of Ce3+ ions also reduces the formation of HC1 color centers after X-ray irradiation.


OSA Continuum ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 563 ◽  
Author(s):  
N. Al Helou ◽  
H. El Hamzaoui ◽  
B. Capoen ◽  
G. Bouwmans ◽  
A. Cassez ◽  
...  

2006 ◽  
Vol 13 (01) ◽  
pp. 13-15 ◽  
Author(s):  
GUANGPENG MA ◽  
JIANRU HAN ◽  
CHANGHONG YANG ◽  
HONGYAN XU ◽  
DONGMEI YANG ◽  
...  

ZnO thin films were prepared on silica glass substrates by a sol–gel spin coating technique. The thickness of the films was about 200 nm. At 370 nm in the ultraviolet region, there is a sharp absorption edge that corresponds to the ZnO intrinsic band gap of 3.30 eV. The structural properties of the films were examined by X-ray diffraction, which demonstrates that the ZnO films were c-axis oriented. From the infrared spectrum, we conclude that ZnO was deposited on silica glass substrates through a high temperature process at 700°C.


2018 ◽  
Vol 65 (8) ◽  
pp. 1591-1597 ◽  
Author(s):  
N. Al Helou ◽  
H. El Hamzaoui ◽  
B. Capoen ◽  
G. Bouwmans ◽  
A. Cassez ◽  
...  

2009 ◽  
Vol 129 (4) ◽  
pp. 595-600
Author(s):  
Tetsuya Makimura ◽  
Takashige Fujimori ◽  
Shuichi Torii ◽  
Hiroyuki Niino ◽  
Kouichi Murakami

Author(s):  
Snehamol Mathew ◽  
Priyanka Ganguly ◽  
Stephen Rhatigan ◽  
Vignesh Kumaravel ◽  
Ciara Byrne ◽  
...  

Indoor surface contamination by microbes is a major public health concern. A damp environment is one potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO<sub>2</sub>) can effectively curb this growing threat.<b> </b>Metal-doped titania in anatase phase has been proved as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu) doped TiO<sub>2 </sub>(Cu-TiO<sub>2</sub>) was evaluated against <i>Escherichia coli</i> (Gram-negative) and <i>Staphylococcus aureus</i> (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO<sub>2 </sub>was carried out <i>via</i> sol-gel technique. Cu-TiO<sub>2</sub> further calcined at various temperatures (in the range of 500 °C – 700 °C) to evaluate the thermal stability of TiO<sub>2</sub> anatase phase. The physico-chemical properties of the samples were characterised through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV-visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO<sub>2</sub> was maintained well, up to 650 °C, by the Cu dopant. UV-DRS results suggested that the visible light absorption property of Cu-TiO<sub>2 </sub>was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasises the introduction of Cu<sup>+</sup> and Cu<sup>2+</sup> ions by replacing Ti<sup>4+</sup> ions in the TiO<sub>2</sub> lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9%) was attained in 30 mins of visible light irradiation by Cu-TiO<sub>2</sub>.


2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Jothi M ◽  
Sowmiya K

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.


Arena Tekstil ◽  
2013 ◽  
Vol 28 (1) ◽  
Author(s):  
Maya Komalasari ◽  
Bambang Sunendar

Partikel nano TiO2 berbasis air dengan pH basa telah berhasil disintesis dengan menggunakan metode sol-gel dan diimobilisasi pada kain kapas dengan menggunakan kitosan sebagai zat pengikat silang. Sintesis dilakukan  dengan prekursor TiCl4 pada konsentrasi 0,3 M, 0,5 M dan 1 M, dan menggunakan templat kanji dengan proses kalsinasi pada suhu 500˚C selama 2 jam. Partikel nano TiO2 diaplikasikan ke kain kapas dengan metoda pad-dry-cure dan menggunakan kitosan sebagai crosslinking agent. Berdasarkan hasil Scanning Electron Microscope (SEM),diketahui bahwa morfologi partikel TiO2 berbentuk spherical dengan ukuran nano (kurang dari 100 nm). Karakterisasi X-Ray Diffraction (XRD) menunjukkan adanya tiga tipe struktur kristal utama, yaitu (100), (101) dan (102) dengan fasa kristal yang terbentuk adalah anatase dan rutile. Pada karakterisasi menggunakan SEM terhadap serbuk dari TiO2 yang telah diaplikasikan ke permukaan kain kapas, terlihat adanya imobilisasi partikel nano TiO2 melalui ikatan hidrogen silang dengan kitosan pada kain kapas. Hasil analisa tersebut kemudian dikonfirmasi dengan FTIR (Fourier Transform Infra Red) yang hasilnya memperlihatkan puncak serapan pada bilangan gelombang 3495 cm-1, 2546 cm-1, dan 511 cm-1,  yang masing-masing diasumsikan sebagai adanya vibrasi gugus fungsi O-H, N-H dan Ti-O-Ti. Hasil SEM menunjukkan pula bahwa kristal nano yang terbentuk diantaranya adalah fasa rutile , yang berdasarkan literatur terbukti dapatberfungsi sebagai anti UV.


2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060018
Author(s):  
E. M. Bayan ◽  
T. G. Lupeiko ◽  
L. E. Pustovaya ◽  
M. G. Volkova

Sn-doped TiO2 nanomaterials were synthesized by sol–gel method. It was shown the phase compositions and phase transitions change with the introduction of different tin amounts (0.5–20[Formula: see text]mol.%). X-ray powder diffraction was used to study the effect of different tin amounts on the anatase–rutile phase transition. It was found that the introduction of ions increases the thermal stability of anatase modifications. The material’s photocatalytic activity was studied in reaction with a model pollutant (methylene blue) photodegradation under UV and visible light activation. The best photocatalytic properties were shown for material, which contains 5[Formula: see text]mol.% of Sn.


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