化学学报 ›› 2008, Vol. 66 ›› Issue (3): 391-397. 上一篇    下一篇

研究论文

反应型二烷基脲凝胶剂及有机溶剂的室温凝胶化研究

熊芸,柳轻瑶,李子福,王宏,杨亚江*   

  1. (华中科技大学化学系 武汉 430074)
  • 投稿日期:2007-02-07 修回日期:2007-06-15 发布日期:2008-02-14
  • 通讯作者: 杨亚江

Reaction-type Gelators of Dialkylurea Derivatives and the Gelation of Organic Solvents at Room Temperature

XIONG Yun; LIU Qing-Yao; LI Zi-Fu; WANG Hong; YANG Ya-Jiang*   

  1. (Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430074)
  • Received:2007-02-07 Revised:2007-06-15 Published:2008-02-14
  • Contact: YANG Ya-Jiang

通常制备有机分子凝胶是在高温下溶解凝胶剂,凝胶剂分子在冷却过程中进行自组装并使有机溶剂凝胶化。该方法限制了某些低沸点溶剂的凝胶化。利用甲苯二异氰酸酯与烷基胺的高反应活性,制备了三种不同烷基链长的反应型凝胶剂甲苯–2, 4–二(N, N’ –烷基)脲。这种反应型凝胶剂能以较低的浓度在室温下使某些芳香族和卤代烃溶剂中形成热可逆的有机分子凝胶。不同烷基链长的亲溶剂作用以及溶剂性质对有机分子凝胶的形成有较大影响。场发射扫描电镜表明这种反应型凝胶剂在有机溶剂中自组装形成纤维状三维网络结构。烷基链长度不同,形成的纤维状聚集体的形态也不同。红外光谱(FT-IR)和核磁共振波谱(1H-NMR)研究表明分子间氢键作用是这种凝胶剂自组装的驱动力。通过X射线衍射(XRD)和分子模拟推测了其聚集体的结构形态。

关键词: 反应型, 二烷基脲凝胶剂, 室温凝胶化

Conventional gelation of organic solvents is unable to perform for some solvent with low boiling point due to the fact that gelator should be dissolved at high temperature and self-assemble in the process of cooling. Herein, three kinds of reaction type of gelators, methylbenzene–2, 4–bis (N, N'–alkyl) urea derivatives were synthesized by using high reactivity of isocyanate and alkylamine. These dialkylurea derivatives can make some aromatic and halide solvents into thermal reversible organogels at room temperature. The formation of organogels was greatly influenced by the solvophilic interaction of alkyl groups and the characteristic of solvents. The images of FE–SEM revealed a three-dimensional network consisting of fiber-like aggregates of the dialkylurea derivatives. Moreover, the length of alkyl groups in dialkylurea lead to different morphology of the aggregates. The study of FT–IR and 1H–NMR further indicates that the hydrogen bonding interaction is a main driving force for the self–assembly of dialkylurea derivatives. A possible self-assembly mode was proposed based on the data of XRD and molecular stimulation.

Key words: reaction type, dialkylurea gelator, gelation at room temperature