Perforated cenosphere-supported pH-sensitive spin probes

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• 作者：E. V. Fomenko ; A. A. Bobko ; A. N. Salanov ; I. A. Kirilyuk ; I. A. Grigor¡¯ev ; V. V. Khramtsov and A. G. Anshits
• 关键词：cenospheres ; nitroxyl radicals ; supported spin probes ; pH measurement using ESR spectroscopy
• 刊名：Russian Chemical Bulletin
• 出版年：2008
• 出版时间：March, 2008
• 年：2008
• 卷：57
• 期：3
• 页码：493-498
• 全文大小：387.5 KB

文摘

Porous supports with an accessible internal volume and a shell providing the diffusive migration of pH-sensitive spin probes were obtained for the first time from hollow aluminosilicate cenospheres isolated from the coal fly ash. Using the methods of scanning electron microscopy and electron spin resonance, the morphology of different porous cenosphere modifications and its influence on the diffusion of spin probes from the internal volume were studied. When supporting aqueous solutions of a radical, the characteristic diffusion time for the mesoporous structure of the support is longer by a factor of 3–5 than that for the macroporous structure. Ferrospinel in a content of 6 wt. % do not virtually affect the diffusion rate of spin probes. A constant rate of radical migration of ∼1 μmol min−1, determined by radical solubility in water, is achieved when a radical in the solid aggregate state is supported on the magnetic cenospheres.