排序方式: 共有35条查询结果,搜索用时 15 毫秒
1.
2.
Dionigi C Calestani G Ferraroni T Ruani G Liotta LF Migliori A Nozar P Palles D 《Journal of colloid and interface science》2005,290(1):201-207
The importance of pure-phase titanium oxide materials as catalysts, sensors, and photonic band-gap materials has been growing steadily. Recently, more attention has been focused on nanostructured titanium oxide showing controlled and periodic porosity on a nanometric scale. The nanocrystal size control of porous nanostructured titanium oxide in an anatase form is a crucial step for the organic template method. Simple template removal by evaporation in an inert atmosphere is reported in this article and compared with the calcination technique usually reported in the literature. The proposed method allows the formation of a double-porous (macro and meso) anatase phase. We demonstrate that it highly preserves the macropore order into a titanium oxide material and induces narrowly dispersed mesopores by controlling the nano-crystal size that is kept around 6 nm. For the proposed method, polystyrene beads are particularly suitable as templates, being evaporated in the temperature range of anatase existence. The final high surface area makes the materials appealing for applications as photocatalysts or sensors. 相似文献
3.
Dionigi C Nozar P Di Domenico D Calestani G 《Journal of colloid and interface science》2004,275(2):445-449
In this paper we propose a simple model for the formation of monodisperse polymer colloids, which provides a convenient set of synthetic parameters for given bead diameters. We provide experimental data in support of this model. 相似文献
4.
Benati L Calestani G Leardini R Minozzi M Nanni D Spagnolo P Strazzari S 《Organic letters》2003,5(8):1313-1316
[reaction: see text] The radical chain reaction of benzenethiol with alkynylthiol esters provides a new, valuable protocol for the tin-free generation of acyl radicals that arise from intramolecular substitution at sulfur by the initial sulfanylvinyl radicals. 相似文献
5.
6.
7.
8.
9.
Gabriele Bocelli Gianluca Calestani Corrado Rizzoli 《Journal of chemical crystallography》1990,20(3):217-221
Crystals of the title compound are monoclinic (C26H25NO): space groupP21/c,a=16.565(3),b=10.328(2),c=12.621(3) Å,=104.02(3)°. The structure was solved by direct methods and refined by block-matrix least-squares to giveR=0.056 andR
w
=0.061 for 1613 reflections above 2(I). The amide moiety is tilted by 19.3(2)° with respect to the mean aromatic ring plane. The two othergem phenyl rings subtend a dihedral angle of 112.2(4)° to each other. The molecules are joined in the solid by N-HO hydrogen bonds. 相似文献
10.
G.D. Andreetti G. Bocelli G. Calestani P. Sgarabotto 《Journal of organometallic chemistry》1984,273(1):31-45
The X-ray analyses of the compounds methylthiotriphenyl-methane, -silicon, -germanium, -tin, and -lead were undertaken to see if the electronic interactions which affect the X-S bond could influence the molecular geometries. The five structures were solved or by direct methods or by Patterson and Fourier techniques and refined anisotropically to R = 0.053, 0.036, 0.031, 0.041, and 0.070 respectively. The central atom exhibits a distorted tetrahedral coordination; only the propeller shape orientation of the phenyl rings seems to be determined by differences in the electronic nature of the central atoms as well as by steric effects. 相似文献