Comparative study of the surface hydroxyl groups of fumed and precipitated silicas. 3. DRIFT characterization of grafted n-hexadecyl chains

Langmuir ◽  
1990 ◽  
Vol 6 (8) ◽  
pp. 1389-1395 ◽  
Author(s):  
A. Burneau ◽  
O. Barres ◽  
A. Vidal ◽  
H. Balard ◽  
G. Ligner ◽  
...  
Keyword(s):  
Comparative Study ◽  
Hydroxyl Groups ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups

Electron microscopy and krypton adsorption characterization of high-purity MgO powder

1986 ◽  
Vol 1 (1) ◽  
pp. 114-119
Author(s):  
M. Bretz ◽  
A. G. Shastri ◽  
J. Schwank
Keyword(s):  
Large Scale ◽  
Gas Adsorption ◽  
Crystal Surface ◽  
Crystal Defects ◽  
Atomic Scale ◽  
Hydroxyl Groups ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Krypton Adsorption

A promising method for the preparation of sizeable quantities of structurally well-defined, highpurity MgO powder is reported. The morphology and surface uniformity of the powder is comparable to that of MgO smokes but with narrow size distribution of particles. Sample characterization of these oxide powders is accomplished by combining structural TEM/STEM examination with krypton gas adsorption isotherms. The latter technique is sensitive to the presence of surface hydroxyl groups and of surface roughness on an atomic scale. Highresolution TEM indicates a perfect cubic morphology, intra-crystallite orientation, and dendritic sintering of cubes. In the STEM mode sharp convergent beam electron diffraction patterns are obtained, and in thick specimen regions Kikuchi lines appear, indicating the absence of crystal defects. After prolonged outgassing to remove surface hydroxyl groups, a krypton adsorption isotherm contains a near vertical submonolayer riser and second layer step along with partial wetting features near saturation. These near-ideal dendritic ceramic powders, therefore, provide a research bridge between single crystal surface studies and large-scale powder technology.

Comparative study of the surface hydroxyl groups of fumed and precipitated silicas. I. Grafting and chemical characterization

Langmuir ◽  
1989 ◽  
Vol 5 (2) ◽  
pp. 447-451 ◽  
Author(s):  
M. Zaborski ◽  
A. Vidal ◽  
G. Ligner ◽  
H. Balard ◽  
E. Papirer ◽  
...  
Keyword(s):  
Comparative Study ◽  
Chemical Characterization ◽  
Hydroxyl Groups ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups

Synthesis and Characterization of TiO2/ PSt/PVP Multilayer Core-Shell Hybrid Microspheres

2012 ◽  
Vol 512-515 ◽  
pp. 2443-2447 ◽  
Author(s):  
Li Ying Guo
Keyword(s):  
Decomposition Temperature ◽  
Tetrabutyl Titanate ◽  
Core Shell ◽  
Hydroxyl Groups ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Ft Ir ◽  
Hydrolysis Of ◽  
Thermal Stability Of

Multiplayer core-shell TiO2/PSt/PVP hybrid microspheres were successfully synthesized by the copolymerization of vinylpyrrolidone in the solution of ethyl acetate with TiO2/PSt core-shell hybrid microspheres which were formed through the encapsulation of KH570-g-TiO2 sol particles with styrene, while the active KH570-g-TiO2 sol particles were prepared by the hydrolysis condensation of KH-570 with tetrabutyl titanate. Characterization technologies of FT-IR and TGA were applied to investigate the structure and the thermal stability of the product. The results showed that the hydroxyl groups from the hydrolysis of KH-570 condensed with the surface hydroxyl groups of TiO2, as well as PSt and PVP were grafted successively onto the surface of KH570-g-TiO2 sol particles. The thermal decomposition temperature of TiO2/PSt/PVP was higher than TiO2/PSt, which also indicated that the obtained product was the final objective product.

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