We report a facile approach to water-dispersible polydiacetylene/rare earth ions nanocomposites with reversible thermochromism. The nanocomposites were prepared by doping rare earth ions Dy^3＋ or Sin^3＋ into layer-s...We report a facile approach to water-dispersible polydiacetylene/rare earth ions nanocomposites with reversible thermochromism. The nanocomposites were prepared by doping rare earth ions Dy^3＋ or Sin^3＋ into layer-structured 10,12-pentacosadiynoic acid （PCDA） nanopar- ticles to obtain PCDA/rare earth ions nanocomposites （PCDA-RE） and subsequently annealing PCDA-RE at the temperature slightly higher than the melting point of pure PCDA crystals, followed by topochemically polymerizing the annealed PCDA-RE. The polymerized PCDA-RE, i.e. poly（10,12-pentacosadiynoic acid）/rare earth ions nanocomposites （PDARE： PDA-Dy or PDA-Sm）, are largely reversible （PDA-Sm） or even completely reversible （PDA-Dy） in the thermochromism, while, without the doping, pure PDA is completely irreversible. It is confirmed that, PDA-RE are also layer-structured with a d-spacing of 5.4 nm, higher than the d-spacing of pure PDA （4.7 nm）. In PDA-RE, the rare earth ions form a layer in-between and interact strongly with the PDA bilayers, being responsible for the high degree or even the complete reversibility. This is the first example to make PDA completely reversible through the doping of rare earth ions; the annealing process is essential for the complete reversibility since it removes any defects in the structure.展开更多
基金V.ACKNOWLEDGEMENTSThisworkwassupportedbytheNationalNatu-ralScienceFoundationofChina（No.21334001andNo.91127030）.V. ACKNOWLEDGEMENTS This work was supported by the National Natu- ral Science Foundation of China （No.21334001 and No.91127030）.
文摘We report a facile approach to water-dispersible polydiacetylene/rare earth ions nanocomposites with reversible thermochromism. The nanocomposites were prepared by doping rare earth ions Dy^3＋ or Sin^3＋ into layer-structured 10,12-pentacosadiynoic acid （PCDA） nanopar- ticles to obtain PCDA/rare earth ions nanocomposites （PCDA-RE） and subsequently annealing PCDA-RE at the temperature slightly higher than the melting point of pure PCDA crystals, followed by topochemically polymerizing the annealed PCDA-RE. The polymerized PCDA-RE, i.e. poly（10,12-pentacosadiynoic acid）/rare earth ions nanocomposites （PDARE： PDA-Dy or PDA-Sm）, are largely reversible （PDA-Sm） or even completely reversible （PDA-Dy） in the thermochromism, while, without the doping, pure PDA is completely irreversible. It is confirmed that, PDA-RE are also layer-structured with a d-spacing of 5.4 nm, higher than the d-spacing of pure PDA （4.7 nm）. In PDA-RE, the rare earth ions form a layer in-between and interact strongly with the PDA bilayers, being responsible for the high degree or even the complete reversibility. This is the first example to make PDA completely reversible through the doping of rare earth ions; the annealing process is essential for the complete reversibility since it removes any defects in the structure.
