Expeditious Base-free Solid-State Reaction between Phenyl Boronates and Hydrogen Peroxide on Silica Gel

Author(s):  
Li Zhang ◽  
Qianqian Chen ◽  
Li Yang ◽  
Yining He ◽  
Keke Guo ◽  
...  

The conversion of phenyl boronates to phenol by hydrogen peroxide (H2O2) usually requires the base as the chemical assistant. In this work, we reported a base-free reaction between the phenyl...

Author(s):  
S.R. Summerfelt ◽  
C.B. Carter

The wustite-spinel interface can be viewed as a model interface because the wustite and spinel can share a common f.c.c. oxygen sublattice such that only the cations distribution changes on crossing the interface. In this study, the interface has been formed by a solid state reaction involving either external or internal oxidation. In systems with very small lattice misfit, very large particles (>lμm) with coherent interfaces have been observed. Previously, the wustite-spinel interface had been observed to facet on {111} planes for MgFe2C4 and along {100} planes for MgAl2C4 and MgCr2O4, the spinel then grows preferentially in the <001> direction. Reasons for these experimental observations have been discussed by Henriksen and Kingery by considering the strain energy. The point-defect chemistry of such solid state reactions has been examined by Schmalzried. Although MgO has been the principal matrix material examined, others such as NiO have also been studied.


Author(s):  
J. R. Heffelfinger ◽  
C. B. Carter

Transmission-electron microscopy (TEM), scanning-electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) were used to investigate the solid-state reaction between a thin yttria film and a (0001) α-alumina substrate. Systems containing Y2O3 (yttria) and Al2O3 (alumina) are seen in many technologically relevant applications. For example, yttria is being explored as a coating material for alumina fibers for metal-ceramic composites. The coating serves as a diffusion barrier and protects the alumina fiber from reacting with the metal matrix. With sufficient time and temperature, yttria in contact with alumina will react to form one or a combination of phases shown by the phase diagram in Figure l. Of the reaction phases, yttrium aluminum garnet (YAG) is used as a material for lasers and other optical applications. In a different application, YAG is formed as a secondary phase in the sintering of AIN. Yttria is added to AIN as a sintering aid and acts as an oxygen getter by reacting with the alumina in AIN to form YAG.


1990 ◽  
Vol 51 (C4) ◽  
pp. C4-111-C4-117 ◽  
Author(s):  
L. J. GALLEGO ◽  
J. A. SOMOZA ◽  
H. M. FERNANDEZ ◽  
J. A. ALONSO

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.


2021 ◽  
pp. 122172
Author(s):  
Chrystian G.M. Lima ◽  
Allan J.M. Araújo ◽  
Rinaldo M. Silva ◽  
Rafael A. Raimundo ◽  
João P.F. Grilo ◽  
...  

2021 ◽  
Vol 31 (3) ◽  
pp. 415-418
Author(s):  
Vladimir Yu. Osipov ◽  
Fedor M. Shakhov ◽  
Nikolai M. Romanov ◽  
Kazuyuki Takai

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