Studies on the Formation of Tin(IY) Oxygen Compounds by Sol-Gel-Process

1992 ◽  
Vol 271 ◽  
Author(s):  
H. Reuter ◽  
M. Kremser ◽  
D. Schröder ◽  
M. Jansen

ABSTRACTSolutions of Sn(OR)4 and R'Sn(OR)3 with different amounts of alkali and alkaline earth metal alkoxides, MI(OR) and MII(OR)2 respectively, have been prepared. Slow evaporation of the solvent resulted in the crystallization of mixed metal alkoxide compounds. Solid state structures have been determined for two examples: K3H[Sn(O/Pr)6]2 and Na2[iPrSn(OiPr)5]·5iPrOH. Solutions as well as solids have been hydrolyzed by moisture. The thermal behaviour of the resulting amorphous powders was investigated by TG, DTA and XRD up to 1000°C in argon atmosphere. The structural evolution during the solid state step mainly depends on the nature and amount of the mono- and bivalent cations. The different influence of both parameters is described.

1995 ◽  
Vol 393 ◽  
Author(s):  
T.R. Jow ◽  
J.P. Zheng

ABSTRACTRuthenium oxide thin films of an amorphous phase were successfully prepared on a titanium (Ti) substrate at temperatures below 160 °C. The sol-gel process using metal alkoxide precursor in nonaqueous solvents was used to prepare these films. The preliminary results showed that a specific capacitance of 430 F/g can be achieved for amorphous ruthenium oxide electrode in sulfuric acid. Films prepared by this method are compared with the films prepared by the thermal decomposition of the aqueous ruthenium chloride solution at temperatures above 300 °C. The specific capacitance, the crystalline structure, and the surface morphology of these films as a function of the preparation temperature were also discussed.


2010 ◽  
Vol 434-435 ◽  
pp. 231-234
Author(s):  
Li Guan ◽  
Bing Bing Fan ◽  
Ming Liang Li ◽  
He Jing Wen ◽  
Kai Li ◽  
...  

SiO2-SiC composite particles were prepared using a sol-gel process. BaTiO3 powders were synthesize through solid-state reaction. They were mixed as microwave absorbents with Fe3O4 powders to obtain the complex absorption. Epoxide resin (EP) was used as matrix and solidified with the mixtures. The techniques of DSC-TG, XRD were used to characterize the composite particles and the obtained compacts. A vector network analyzer was used to measure the reflectivity of the SiO2-SiC-based composites. The effects of the aborbents’ contents on the reflection of the microwave absorption materials were disscussed. It was found that SiO2-SiC composites could be prepared using sol-gel process and BaTiO3 powders could be synthesize through solid-state reaction. The results indicated that SiO2-SiC composite is contribute to absorb microwave, where SiO2-SiC: BaTiO3: Fe3O4 = 6:2:2 (vol %), the frequency region in which the maximum reflectivity is more than -10 dB is 5.4-7.6 GHz.


1998 ◽  
Vol 519 ◽  
Author(s):  
P.H. Mutin ◽  
C. Delenne ◽  
D. Medoukali ◽  
R. Corriu ◽  
A. Vioux

AbstractTransition metal oxide / phenylphosphonate hybrids with M/P ratios ranging from 1 to 5, (M= Ti, Zr) and metal phosphonates (M/P = 0.5) have been prepared by a sol-gel process involving in a first step the non-hydrolytic condensation between metal alkoxide and phosphonic acid leading to M-O-P bonds, followed by the hydrolysis-condensation of the remaining M-OR groups. The composition, texture and structure of the materials were investigated using EDX, TGA, XRD, IR and 31P NMR.


Inorganics ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 128 ◽  
Author(s):  
Kerstin Scheurell ◽  
Erhard Kemnitz

The potential of fluorolytic sol–gel synthesis for a wide variety of applications in the field of optical materials is reviewed. Based on the fluorolytic sol–gel synthesis of nanometal fluorides, sols of complex fluorometalates have become available that exhibit superior optical properties over known classical binary metal fluorides as, for instance, magnesium fluoride, calcium fluoride, or strontium fluoride, respectively. The synthesis of transparent sols of magnesium fluoroaluminates of the general composition MgxAlFy, and fluoroperovskites, [K1−xNax]MgF3, is reported. Antireflective coatings fabricated from MgF2, CaF2, MgxAlFy, and [K1−xNax]MgF3 sols and their relevant properties are comprehensively described. Especially the heavier alkaline earth metal fluorides and the fluorperovskites crystallizing in a cubic crystal structure are excellent hosts for rare earth (RE) metals. Thus, the second chapter reflects the synthesis approach and the properties of luminescent systems based on RE-doped alkaline earth metal fluorides and [K1−xNax]MgF3 phases.


Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 841
Author(s):  
Sung Jin Park ◽  
Myong Euy Lee ◽  
Hyeon Mo Cho ◽  
Sangdeok Shim

The sol–gel polymerization of alkoxysilanes is a convenient and widely used method for the synthesis of silicon polymers and silicon–organic composites. The development of new sol–gel precursors is very important for obtaining new types of sol–gel products. New condensation polymer precursors containing consecutive silicon atoms—decaisopropoxycyclopentasilane (CPS) and dodecaethoxyneopentasilane (NPS)—were synthesized for the preparation of polysilane–polysiloxane material. The CPS and NPS xerogels were prepared by the sol–gel polymerization of CPS and NPS under three reaction conditions (acidic, basic and neutral). The CPS and NPS xerogels were characterized using N2 physisorption measurements (Brunauer–Emmett–Teller; BET and Brunauer-Joyner-Halenda; BJH), solid-state CP/MAS (cross-polarization/magic angle spinning) NMRs (nuclear magnetic resonances), TEM, and SEM. Their porosity and morphology were strongly affected by the structure of the precursors, and partial oxidative cleavage of Si-Si bonds occurred during the sol–gel process. The new condensation polymer precursors are expected to expand the choice of approaches for new polysilane–polysiloxane.


2008 ◽  
Vol 368-372 ◽  
pp. 1007-1009
Author(s):  
M.T. Tsai ◽  
P.J. Tsai ◽  
H.C. Chang

Homogeneous and transparent enstatite fibers were prepared via the sol-gel process of metal alkoxide precursors. The gel-to-ceramic conversion was characterized. The solution compositions had a significant influence on the microstructural evolution of gel fibers. Infrared studies indicated that bidentate bridging ligands were formed between acetate and metal ions, which enhanced spinnability remarkably. The as-drawn fibers were essentially microporous. On heating to 800 oC, enstatite ceramic fibers exhibited mesoporous structures with nanocrystals in size. The optical transmittance of enstatite ceramic fiber in the visible range was around 90 % after heating at 800 oC.


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