H-1 nuclear magnetic resonance study of mixed-valent dodecylamine-intercalated vanadium oxide nanosheets

초록

Alkyl-chain dynamics in the mixed-valent dodecylamine-intercalated vanadium oxide nanosheets (C12VONS) was investigated by means of 400-MHz H-1 nuclear magnetic resonance. Two C12VONS samples with distinct alkylammonium-to-alkylamine ratios showed distinct alkyl-chain dynamics, the alkylammonium chains being apparently more disordered than the alkylamine chains. The high-temperature spin-lattice relaxation is dominated by the conformational chain defects and the reorientational motions of the alkyl chains, respectively, in the alkylammonium-abundant system and in the alkylamine-abundant system. The reorientational and conformational changes of the alkyl chains appear to be uncorrelated with the magnetic transitions. (C) 2012 Elsevier Ltd. All rights reserved.

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