Acta Chim. Sinica ›› 2015, Vol. 73 ›› Issue (5): 441-449.DOI: 10.6023/A15010083 Previous Articles     Next Articles



张贝贝, 马驰, 王小刚, 胡敏标, 王晓乐, 王维   

  1. 南开大学化学学院 功能高分子材料教育部重点实验室和高分子化学研究所 合成软物质中心 天津化学化工协同创新中心 天津 300071
  • 投稿日期:2015-01-30 发布日期:2015-03-23
  • 通讯作者: 王维
  • 基金资助:


Langmuir and of Langmuir-Blodgett Films of Two Dumbbell-shaped Hybrids Composed of A Polyoxometallate and Two Polyhedral Oligosilsesquioxanes

Zhang Beibei, Ma Chi, Wang Xiaogang, Hu Minbiao, Wang Xiaole, Wang Wei   

  1. Center for Synthetic Soft Materials, The Key Laboratory of Functional Polymer Materials of Ministry of Education and Institute of Polymer Chemistry, Nankai University, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300071
  • Received:2015-01-30 Published:2015-03-23
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21274069 and 21334003) and Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry.

In this work we report the Langmuir film-forming process and morphology of Langmuir-Blodgett (LB) films of two dumbbell-shaped hybrids at the air-water interface. The hybrids are two A-B co-cluster molecules composed of two different clusters that are covalently linked together by an organic tether. Cluster A is a trivanadium-substituted derivative of a Wells-Dawson-type tungsten polyoxometalate (POM) anion and cluster B is derivatives of polyhedral oligomeric silsesquioxane (POSS) cubic cage in which seven isobutyl or isooctyl groups attached to seven corners of the cage and an aminopropyl group attached to the eighth corner. The organic tether is a terephthalic acid. In our experiment, we used Langmuir technique to determine the surface pressure-area (π-A) isotherms and cyclic compression-expansion isotherms of the two hybrids, and then studied their Langmuir film-forming processes at the air-water interface. Our investigations show that the two hybrids can form good Langmuir films, indicating that they have good amphiphilicity. The Langmuir films have a hybrid structure: a TBA-encapsulated POM layer faced to the water surface and a POSS layer contacted with air. Meanwhile, we also used Langmuir-Blodgett (LB) technique to prepare LB film specimens for atomic force microscopy (AFM) characterization to study the surface morphology of the films and for transmission electron microscopy (TEM) characterization to study the morphology of the films. The root mean squares (RMS) of surface roughness of the LB films are smaller than 0.6 nm, only one sixth of the molecular length, meaning a smooth surface. Due to existence of tungsten and vanadium in the POM cluster, we successfully characterized the morphology of the LB films and observed a two-phase morphology in which the dark domains embedded a bright matrix. Appearance of the dark domains means formation of more ordered structures. The and size differences between the domains and matrix are intensified during the gas-liquid and liquid-solid phase transitions. This means that it is a fluctuation phenomenon of the morphology occurring in the phase transition of condensed matter. All in all, the findings provide a new method for construction of the monomolecular LB films with a hybrid structure via a rational design of hybrid molecules.

Key words: hybrids, polyoxometalates, polyhedral oligosilsesquioxanes, Langmuir films, LB films