Deep-ultraviolet transparent monolithic sol–gel derived silica–REPO4 (RE = Y, La–Lu except Pm) glass-ceramics: characterization of the crystal structure and ultraviolet absorption edge, and application to narrow-band UVB phosphors

2015 ◽  
Vol 3 (38) ◽  
pp. 9894-9901 ◽  
Author(s):  
Shiori Yamaguchi ◽  
Kenji Moriyama ◽  
Koichi Kajihara ◽  
Kiyoshi Kanamura

Silica–REPO4 glass-ceramics with high deep-ultraviolet transparency (left) and a silica–(Gd,Pr)PO4 phosphor promising as a narrow-band ultraviolet B phosphor (right) have been developed.

ChemInform ◽  
1989 ◽  
Vol 20 (9) ◽  
Author(s):  
T. HAMASAKI ◽  
K. EGUCHI ◽  
Y. KOYANAGI ◽  
A. MATSUMOTO ◽  
T. UTSUNOMIYA ◽  
...  

2008 ◽  
Vol 396-398 ◽  
pp. 153-156 ◽  
Author(s):  
Xanthippi Chatzistavrou ◽  
E. Hatzistavrou ◽  
Nikolaos Kantiranis ◽  
Lambrini Papadopoulou ◽  
Eleana Kontonasaki ◽  
...  

The aim of this study was the fabrication using a sol-gel technique of a new glass-ceramic with potential use in dental applications. The characterization of the composition and microstructural properties of the produced material confirmed the similarity between the new sol-gel derived glass-ceramic and a commercial leucite based fluorapatite dental glass-ceramic. The produced material has potential application in dental restorations and it is expected to exhibit better control of composition, microstructure and properties due to the intrinsic advantages of the sol-gel preparation method.


2012 ◽  
Vol 96 (2) ◽  
pp. 476-480 ◽  
Author(s):  
Go Kawamura ◽  
Ryota Yoshimura ◽  
Kazunari Ota ◽  
Song-Yul Oh ◽  
Norio Hakiri ◽  
...  

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 259
Author(s):  
Natalia Pawlik ◽  
Barbara Szpikowska-Sroka ◽  
Tomasz Goryczka ◽  
Ewa Pietrasik ◽  
Wojciech A. Pisarski

The synthesis and characterization of multicolor light-emitting nanomaterials based on rare earths (RE3+) are of great importance due to their possible use in optoelectronic devices, such as LEDs or displays. In the present work, oxyfluoride glass-ceramics containing BaF2 nanocrystals co-doped with Tb3+, Eu3+ ions were fabricated from amorphous xerogels at 350 °C. The analysis of the thermal behavior of fabricated xerogels was performed using TG/DSC measurements (thermogravimetry (TG), differential scanning calorimetry (DSC)). The crystallization of BaF2 phase at the nanoscale was confirmed by X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM), and the changes in silicate sol–gel host were determined by attenuated total reflectance infrared (ATR-IR) spectroscopy. The luminescent characterization of prepared sol–gel materials was carried out by excitation and emission spectra along with decay analysis from the 5D4 level of Tb3+. As a result, the visible light according to the electronic transitions of Tb3+ (5D4 → 7FJ (J = 6–3)) and Eu3+ (5D0 → 7FJ (J = 0–4)) was recorded. It was also observed that co-doping with Eu3+ caused the shortening in decay times of the 5D4 state from 1.11 ms to 0.88 ms (for xerogels) and from 6.56 ms to 4.06 ms (for glass-ceramics). Thus, based on lifetime values, the Tb3+/Eu3+ energy transfer (ET) efficiencies were estimated to be almost 21% for xerogels and 38% for nano-glass-ceramics. Therefore, such materials could be successfully predisposed for laser technologies, spectral converters, and three-dimensional displays.


1988 ◽  
Vol 71 (12) ◽  
pp. 1120-1124 ◽  
Author(s):  
TOSHIO HAMASAKI ◽  
KATSUYA EGUCHI ◽  
YOSHINORI KOYANAGI ◽  
AKIRA MATSUMOTO ◽  
TAIZO UTSUNOMIYA ◽  
...  

Author(s):  
Bui Xuan Vuong

In this paper, three ceramic compositions 50SiO2-50CaO (A), 45SiO2-45CaO-10P2O5 (B) and 40SiO2-40CaO-20P2O5 (C) (wt %) were synthesized by using the sol-gel technique. XRD analysis demonstrates that only sample C can form the glass material. Treated temperatures and heated times were also evaluated. Analysis data showed that the bioglass 40SiO2-40CaO-20P2O5 (wt %) can successfully elaborate when the ceramic powder heated at 750 oC for 3 hours. ‘‘In vitro’’ experiment was effectuated to investigate the bioactivity of bioglass 40SiO2-40CaO-20P2O5 by soaking powder samples in SBF solution. Obtained result confirmed the formation of hydroxyapatite (HA) phase on glass’s surface after 15 days of immersion, in which HA formation orients following (211) and (222) miller planes in crystalline structure of HA phase. Keywords Sol-gel; bioglass; hydroxyapatite; SBF; bioactivity References [1] D.F. Williams, Definitions in Biomaterials, Consensus Conference for the European Society for Biomaterials, Chester, UK, 1986.[2] L.L. Hench, Bioceramics: From Concept to Clinic, Journal of the American Ceramic Society, 74 (1991) 1487.[3] L.L. Hench, The story of Bioglass, Journal of Materials Science: Materials in Medicine, 17 (2006) 967.[4] X.V. Bui, H. Oudadesse, Y. Le Gal, A. Mostafa, P.Pellen and G. Cathelineau, Chemical Reactivity of Biocomposite Glass-Zoledronate, Journal of the Australian Ceramic Society, 46 (2010) 24.[5] L.L. Hench, Genetic design of bioactive glass, Journal of the European Ceramic Society, 29 (2009) 1257.[6] S. Kumar, P. Vinatier, A. Levasseur, K.J. Rao, Investigations of structure and transport in lithium and silver borophosphate glasses, Journal of Solid State Chemistry, 177 (2004)1723.[7] Z. Hong, A. Liu, L. Chen, X. Chen, X. Jing, Preparation of bioactive glass ceramic nanoparticles by combination of sol–gel and coprecipitation method, Journal of Non-Crystalline Solids, 355 (2009) 368.[8] D.B. Joroch, D.C. Clupper, Modulation of zinc release from bioactive sol–gel derived SiO2‐CaO‐ZnO glasses and ceramics, Journal of Biomedical Materials Research Part A, 82A (2007) 575.[9] J. Roman, S. Padilla, M. Vallet-Regi, Sol−Gel Glasses as Precursors of Bioactive Glass Ceramics, Chemistry of Materials, 15 (2003) 798.[10] J. Lao, J.M. Nedelec, Ph. Moretto, E. Jallot, Biological activity of a SiO2-CaO-P2O5 sol-gel glass highlighted by PIXE-RBS methods, Nuclear Instruments and Methods in Physics Research Section B, 245 (2006) 511.[11] [11] M. Vallet-Regi, L. Ruiz-Gonzalez, I. Izquierdo, J.M. Gonzalez-Calbet, Revisiting silica based ordered mesoporous materials: medical applications, Journal of Materials Chemistry, 16 (2006) 26.[12] W. Xia, J. Chang, Preparation and characterization of nano-bioactive-glasses (NBG) by a quick alkali-mediated sol–gel method, Materials Letters 61 (2007) 3251.[13] R. Li, A.E. Clark, L.L. Hench, An investigation of Bioactive Glass Powders by Sol-Gel Processing, Transactions of 16th Annual Meeting of the Societey for Biomaterials, 12 (1990) 40.[14] J. Lao, J.M. Nedelec, P. Moretto, E. Jallot, Imaging physicochemical reactions occurring at the pore surface in binary bioactive glass foams by micro ion beam analysis, Applied Materials and Interfaces, 6 (2010) 1737.[15] A. Balamurugan, G. Balossier, S. Kannan, J. Michel, A.H.S. Rebelo, J.M.F. Ferreira, Development and in vitro characterization of sol–gel derived CaO–P2O5–SiO2–ZnO bioglas, Acta Biomaterialia, 3 (2007) 255.[16] Z. Hong, A. Liu, L. Chen, X. Chen, X. Jing, Bioactive glass prepared by sol–gel emulsion, Journal of Non-Crystalline Solids, 355 (2009) 368.[17] O. Peital, E.D. Zanotto, L.L. Hench, Highly bioactive P2O5-Na2O-CaO-SiO2 glass-ceramics, Journal of Non-Crystalline Solids, 292 (2001) 115.[18] J. Liu, X. Miao, Sol-gel derived bioglass as a coating material for porous alumina scaffolds, Ceramics International, 30 (2004) 1781.[19] T. Kokubo, H. Takadama, How useful is SBF in predicting in vivo bone bioactivity. Biomaterials 27 (2006) 2907.[20] M. Dziadek, B. Zagrajczuk, P. Jelen, Z. Olejniczak, K.C. Kowalska, Structural variations of bioactive glasses obtained by different synthesis routes, Ceramics International, 42 (2016) 14700.[21] R. Lakshmi, V. Velmurugan and S. Sasikumar, Preparation and Phase Evolution of Wollastonite by Sol-Gel Combustion Method Using Sucrose as the Fuel, Combustion Science and Technology, 185 (2013) 1777.[22] G. Voicu, A. Bădănoiu, E. Andronescu1, C. M. Chifiruc, Synthesis, characterization and bioevaluation of partially stabilized cements for medical applications, Central European Journal of Chemistry, 11 (2013) 1657.[23] M.V. Regi, Ceramics for medical applications, Journal of the Chemical Society, Dalton Transactions, 2 (2001) 97.[24] G. Voicu, A.I. Bădănoiu, E. Andronescu, C.M. Chifiruc, Synthesis, characterization and bioevaluation of partially stabilized cements for medical applications, Central European Journal of Chemistry, 11 (2013) 1657.M. Wu, T. Wang, Y. Wang, F. Li, M. Zhou, X. Wu, A novel and facile route for synthesis of fine tricalcium silicate powders, Materials letters, 227 (2018), 187.


2015 ◽  
Vol 2 (1) ◽  
pp. 81
Author(s):  
Yetria Rilda ◽  
Abdi Dharma ◽  
Syukri Arief ◽  
Admin Alif

 ABSTRACT The structure and characterization of the titania (M-TiO2) can be modified by metal doped and calcinations temperatures variation by sol-gel method. Characterization of gel and M-TiO2 powder realized by FT-IR, TGA, XRD, Photo Optic and SEM. Titania has two crystal structures such as anatase and rutile. Anatase structures shown higher photocatalytic properties than rutile. The crystal structure was characterized to JCPS reference no. 21-1272, 2Ө : 25.3° identically as anatase structure and 2Ө : 27.3° as rutile. Structure modification is depend on calcinations temperature change. At 400°C the anatase structure was formed. The anatase intensity was increased at 500°C and at 600°C anatase transportation to rutile was found and anatase mixture was obtained. Several types of dopant can inhibit anatase to rutil transformation process at temperature ≥ 600°C. Park et al.,[1] reported that calcinations temperature and valence ion dopant influence the crystal size. Based on Scherrer’s equation the crystal size can be calculated by using the XRD  data. The crystal size of maximum intensity which was identified as anatase structure at 500°C as following Fe-TiO2 10.6 nm, MoTiO2 16.8 nm.  M-TiO2 character through inhibition of E. Coli bacteria growth was great infulenced by particle size and dopant ion type. This character shown by MIC value (Minimal Inhibition Concentration)) of each Fe, Mo-TiO2 between 0.35 – 0.45%. Keywords : crystal structure, characterization, titania, sol-gel


2011 ◽  
Vol 194-196 ◽  
pp. 476-479
Author(s):  
Yu Cai ◽  
Zhao Yang Wu ◽  
Shen Li Zhao ◽  
Ji Ne Zhu

The nano-NiO powder was prepared by sol-gel method combining heat treatment technology and its structure and morphology were explored. In addition, the NiO powder electrochemical properties were tested by constant current charging and discharging. The results show that the stable performance sol can be composed by nickel acetate as source of nickel and PAA as chelating agent. Nano-NiO powder of crystal structure integrity, particle uniformity can be prepared by the sol. The gel decomposes completely and gradually forms nanocrystal at 430οC. Its grain size is gradually increasing when the annealing temperature rise. The nano-NiO powder sintered at 600°C exhibits uniform particle, integrity crystal structure, low aggregation and superior electrochemistry performance and may be used in Li-ion battery as the anode material.


2007 ◽  
Vol 555 ◽  
pp. 377-381
Author(s):  
R. Krsmanović ◽  
Giovanni Bertoni ◽  
Gustaaf Van Tendeloo

Samples of transparent glass-ceramics in the ternary system Li2O-Al2O3-SiO2 (LAS), with Er2O3 as a luminescent dopant, are investigated. The initial glass is obtained by the classical melting technique. In order to induce ceramization of the glass, TiO2 and ZrO2 are added in small amount as nucleating agents. The thermal treatments at 730 and 770°C are carried out to promote formation of titanium zirconate solid solution precipitates. The spatial distribution of the precipitates in the material, their morphology, and their composition are investigated with TEM, HRTEM, HAADF-STEM, EELS and EFTEM. The results demonstrate that with the glass-melting preparation technique it is possible to achieve small nanoparticles with uniform distribution and higher number density than with the sol-gel glass preparation.


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