We have already reported that cross-linked fluoroalkyl end-capped vinyltrimethoxysilane oligomeric nanoparticles [RF-(VM-SiO2)n-RF] - encapsulated 1,1'-bi(2-naphthol) (BINOL) can be prepared by the sol-gel reaction of the corresponding oligomer in the presence of BINOL under alkaline conditions.1) RF-(VM-SiO2)n-RF/BINOL nanocomposites thus obtained were found to afford a clear weight loss at 800 oC, which corresponds to the content of fluorinated oligomer in the composites.1, 2) However, unexpectedly, RF-(VM-SiO2)n-RF/BINOL nanocomposites were found to exhibit no weight loss corresponding to the presence of BINOL in the composites at 800 oC under atmospheric conditions.1, 2)Here we report the light stability of RF-(VM-SiO2)n-RF nanocomposites-encapsulated low molecular weight aromatic compounds such as BINOL and 2-hydroxy-4-methoxy benzophenone (HMB) under UV (?max: 254 nm) irradiation. We have found that these encapsulated aromatic compounds can exhibit an extremely higher light resistance characteristic, compared with that of the parent aromatic compounds. Especially, after 8 hr UV light (?max: 254 nm) irradiation toward RF-(VM-SiO2)n-RF/BINOL nanocomposites, encapsulated BINOL into cross-linked RF-(VM-SiO2)n-RF oligomeric nanoparticle cores was unable to have the releasing ability into organic solvents such as methanol. However, calcinated RF-(VM-SiO2)n-RF/BINOL nanocomposites at 800 oC were found to give an effective releasing characteristic for encapsulated BINOL into methanol, indicating that the encapsulated BINOL should have excellent thermal and light stabilities in the cross-linked oligomeric nanoparticle cores.1) Sawada, H.; Matsuki, Y.; Goto, Y.; Kodama, S.; Sugiya, M.; Nishiyama, Y. Bull. Chem. Soc. Jpn. 2010, 83 , 75.2) a) Goto, Y.; Sawada, H. et al. Colloid Polym. Sci. 2011, 190 , 11;b) Goto, Y.; Sawada, H. et al. J. Colloid Interface Sci. 2011, 362  , 375.

Preparation and light stability of fluoroalkyl end-capped vinyltrimethoxysilane oligomer/silica nanocomposites-encapsulated low molecular weight aromatic compounds

246th National Meeting (2013)

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