Usually, it is well known that anatase titanium oxide (an-TiO2) transforms irreversibly to rutile titanium oxide around 600 ~ 750 �C.1) However, we have very recently found that fluoroalkyl end-capped vinyltrimethoxysilane oligomer/silica/ anatase titanium oxide nanocomposites [RF-(VM-SiO2)n-RF/an-TiO2] can keep completely its structure without phase transformation to rutile even after calcination at 1000 oC, and RF-(VM-SiO2)n-RF/an-TiO2 nanocomposite after calcination can exhibit the same photocatalytic activity as that before calcination.2) Here we report that fluoroalkyl end-capped vinyltrimethoxysilane oligomer [RF-(VM)n-RF] can be applicable to the preparation of the corresponding oligomer/silica/an-TiO2nanocomposites-encapsulated a variety of low molecular weight aromatic compounds.We have prepared RF-(VM-SiO2)n-RF/an-TiO2 nanocomposites-encapsulated a variety of aromatic compounds such as bisphenol A, 1,1'-bi-2-naphthol (BINOL) and C60 by the sol-gel reactions of RF-(VM)n-RF oligomer with an-TiO2 nanoparticles in the presence of the corresponding aromatic compounds under alkaline conditions. Thermal stability of these obtained nanocomposites was studied by the use of TGA (thermogravimetric analyses) measurments. Interestingly, encapsulated aromatic compounds such as bisphenol A and BINOL into these nanocomposites were found to exhibit no weight loss behavior even after calcination at 1000 oC, although encapsulted C60 exhibited a clear weight loss under similar conditions. These fluorinated an-TiO2 nanocomposites-encapsulated aromatic compounds were able to keep completely its structure without phase transformation to rutile even after calcination at 1000 oC. More interstingly, these fluorinated nanocomposites after calcination at 1000 oC can exhibit the superior photocatalytic activity to that of RF-(VM-SiO2)n-RF/an-TiO2 nanocomposites after calcination and original an-TiO2nanoparticles before calcination under the similar conditions.1) X. Peng and A. Chen, Adv. Funct. Mater., 16  , 1355 (2006).2) S. Guo, H. Yoshioka, H. Kakehi, Y. Kato, M. Miura, N. Isu, B. Ameduri, and H. Sawada,     J. Colloid Interface Sci., 387  , 141 (2012).

Preparation, thermal stability, and photocatalytic activity of fluoroalkyl end-capped vinyltrimethoxysilane oligomer/silica/anatase titanium oxide nanocomposites-encapsulated a variety of low-molecular weight aromatic compounds

246th National Meeting (2013)

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