Sol-gel processing, spectral features and thermal stability of Li-stuffed Li6CaLa2Nb2O12:RE garnet phosphors (RE = Pr, Sm, Tb, Dy)

2021 ◽  
pp. 111825
Author(s):  
Panpan Du ◽  
Qi Zhu ◽  
Xiaodong Li ◽  
Xudong Sun ◽  
Byung-Nam Kim ◽  
...  
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.


2009 ◽  
Vol 480 (2) ◽  
pp. 908-911 ◽  
Author(s):  
E. Kin ◽  
T. Fukuda ◽  
S. Yamauchi ◽  
Z. Honda ◽  
H. Ohara ◽  
...  

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 228 ◽  
Author(s):  
Ekaterina S. Dolinina ◽  
Elizaveta Yu. Akimsheva ◽  
Elena V. Parfenyuk

Powerful antioxidant α-lipoic acid (LA) is easily degraded under light and heating. This creates difficulties in its manufacture, storage and reduces efficiency and safety of the drug. The purpose of this work was to synthesize novel silica-based composites of LA and evaluate their ability to increase photo and thermal stability of the drug. It was assumed that the drug stabilization can be achieved due to LA-silica interactions. Therefore, the composites of LA with unmodified and organomodified silica matrixes were synthesized by sol-gel method at the synthesis pH below or above the pKa of the drug. The effects of silica matrix modification and the synthesis pH on the LA-silica interactions and kinetics of photo and thermal degradation of LA in the composites were studied. The nature of the interactions was revealed by FTIR spectroscopy. It was found that the rate of thermal degradation of the drug in the composites was significantly lower compared to free LA and mainly determined by the LA-silica interactions. However, photodegradation of LA in the composites under UV irradiation was either close to that for free drug or significantly more rapid. It was shown that kinetics of photodegradation was independent of the interactions and likely determined by physical properties of surface of the composite particles (porosity and reflectivity). The most promising composites for further development of novel silica-based formulations were identified.


2013 ◽  
Vol 334-335 ◽  
pp. 60-64 ◽  
Author(s):  
Mohammad Reza Loghman-Estark ◽  
Reza Shoja Razavi ◽  
Hossein Edris

Scandia, yttria doped zirconia ((ZrO2)0.96(REO1.5)0.04(RE=Sc3+, Y3+)) nanoparticles were prepared by the modified sol-gel method. The microstructure of the products was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Thermal stabillity of SYSZ nanocrystals were also investigated. The SYSZ nanocrystals synthesized with EGM:Zr+4mole ratio 4:1, calcined at 700°C, have average diameter of ~20 nm.


2012 ◽  
Vol 209 (7) ◽  
pp. 1219-1224 ◽  
Author(s):  
Guanlin Feng ◽  
Yanfeng Xue ◽  
Hongzhi Shen ◽  
Shuo Feng ◽  
Liang Li ◽  
...  

2007 ◽  
Vol 61 (8-9) ◽  
pp. 1751-1755 ◽  
Author(s):  
K.V. Baiju ◽  
P. Periyat ◽  
P. Krishna Pillai ◽  
P. Mukundan ◽  
K.G.K. Warrier ◽  
...  

1997 ◽  
Vol 8 (1-3) ◽  
pp. 437-442 ◽  
Author(s):  
E. Ramos ◽  
T. Lopez ◽  
P. Bosch ◽  
M. Asomoza ◽  
R. Gomez

2011 ◽  
Vol 239-242 ◽  
pp. 294-297
Author(s):  
Cun Jin Xu ◽  
Qun Lü ◽  
Hai Ke Feng

A ternary Eu(III) complex with salicylic acid (Hsal) ando-phenanthroline (phen) was synthesized and then incorporated into silica matrix by sol-gel method. The luminescence behavior of the complex in silica gel was studied compared with that of the pure complex by means of emission, excitation spectra and thermogravimetic analysis. The results indicate that the complex Eu(sal)3(phen) in silica gel shows fewer emission lines than pure Eu(sal)3(phen) and the luminescence intensity ratio of the5D0→7F2transition to the5D0→7F1transition is lower than that of the latter. The thermal stability of Eu(sal)3(phen) is enhanced greatly through the introduction of the complex into silica matrix.


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