Binary organogelators which show light and temperature responsiveness.
Binary organogelators which show light and temperature responsiveness.
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DOI：
10.1039/b304224c
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发表时间：
2003-07
影响因子：
3.2
通讯作者：
Masatsugu Ayabe;Takanori Kishida;Norifumi Fujita;K. Sada;S. Shinkai
中科院分区：
文献类型：
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作者：
Masatsugu Ayabe;Takanori Kishida;Norifumi Fujita;K. Sada;S. Shinkai
本文研究了10种蒽-9-羧酸烷基铵（CnH（2n+1）NH ~（3+），n=4-11，12和16）（1 n）的成胶能力。在环己烷中，1（4）、1（5）、1（6）和1（7）仅提供沉淀，而1（11）、1（12）和1（16）提供非常粘稠的溶液。相反，1（8）、1（9）和1（10）产生凝胶。1（10）的临界胶凝浓度非常低（5.0 × 10（-4）mol dm（-3））。SEM观察表明，在凝胶相的形态变化从直的原纤卷曲的原纤与n的增加，而在溶胶相的片状，二维聚集体的形成是公认的。当环己烷1（10）凝胶经光照射（λ> 300 nm）后，单体蒽的紫外-可见吸收峰减少，凝胶转变为溶胶。通过暗视野光学显微镜证实，支持凝胶形成的纤维束随着光照射时间逐渐消失。当在黑暗中将该溶胶在30 ℃下加热时，凝胶没有再生，但产生1（10）的沉淀。当将该溶胶在环己烷的沸点下加热一次并冷却至15 ℃时，溶液再次变成凝胶。这一发现表明，凝胶形成所需的纤维状结构在30 ℃下不会重构，而是仅在热环己烷溶液冷却时获得。
The gelation ability of 10 alkylammonium (CnH(2n+1)NH3+ where n=4-11, 12 and 16) anthracene-9-carboxylates (1n) has been evaluated. In cyclohexane, 1(4), 1(5), 1(6) and 1(7) only provided precipitates whereas 1(11), 1(12) and 1(16) provided very viscous solutions. In contrast, 1(8) 1(9) and 1(10) resulted in gels. The critical gelation concentration of 1(10) was very low (5.0 x 10(-4) mol dm(-3)). SEM observations showed that in the gel phase the morphology changes from straight fibrils to frizzy fibrils with the increase in n, whereas in the sol phase the formation of the sheet-like, two-dimensional aggregate is recognized. When the cyclohexane 1(10) gel was photoirradiated (lambda > 300 nm), the UV-VIS absorption bands assignable to monomeric anthracene were decreased and the gel was changed into the sol. It was confirmed by dark-field optical microscopy that the fibrillar bundles supporting the gel formation gradually disappear with photoirradiation time. When this sol was warmed at 30 degrees C in the dark, the gel was not regenerated but the precipitation of 1(10) resulted. When this sol was heated once at the bp of cyclohexane and cooled to 15 degrees C, the solution was changed into the gel again. This finding indicates that the fibrillar structure required for the gel formation is not reconstructed at 30 degrees C but obtained only when the hot cyclohexane solution is cooled.