高等学校化学学报 ›› 2019, Vol. 40 ›› Issue (3): 548-554.doi: 10.7503/cjcu20180679

• 高分子化学 • 上一篇    下一篇

自组装光致形变功能偶氮分子玻璃微球

唐波, 黄浩, 吴兵, 李旭, 王晓工()   

  1. 清华大学化学工程系, 北京 100084
  • 收稿日期:2019-10-09 出版日期:2019-12-24 发布日期:2018-12-24
  • 作者简介:

    联系人简介: 王晓工, 男, 博士, 教授, 博士生导师, 主要从事光电功能高分子材料方面的研究. E-mail: wxg-dce@mail.tsinghua.edu.cn

  • 基金资助:
    国家自然科学基金(批准号: 51233002)资助.

Self-assembled Azo Molecular Glass Microspheres with Rapid Photoinduced Deformation

TANG Bo, HUANG Hao, WU Bing, LI Xu, WANG Xiaogong*()   

  1. Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • Received:2019-10-09 Online:2019-12-24 Published:2018-12-24
  • Contact: WANG Xiaogong E-mail:wxg-dce@mail.tsinghua.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.51233002).

摘要:

通过逐滴滴加去离子水的方法, 探究了具有快速光响应的偶氮分子玻璃(IAC-4)在初始浓度范围为1.0~5.0 mg/mL条件下的自组装, 制备了形貌规整、 尺寸均一的胶体球, 并利用动态光散射技术(DLS)测定了IAC-4胶体球的流体力学半径. 通过测定一系列初始浓度的IAC-4溶液的临界水含量, 探究了IAC-4在自组装过程中析出、 聚集成核和核生长的规律. 研究发现, 临界水含量与IAC-4初始浓度的关系符合二元混合溶剂中固体溶质的溶解度变化规律. 通过调节去离子水的滴加量, 研究了自组装过程中, IAC-4聚集体流体力学半径呈现先增大后减小的趋势. IAC-4胶体球的水分散液, 通过室温干燥得到的固态IAC-4微球在线性偏振激光(488 nm, 100 mW/cm2)垂直辐照下表现出快速的光响应特性. 当辐照时间为1 min时, IAC-4微球快速地拉伸形变, 形成平均长径比为1.44的椭圆形粒子. 随着光辐照时间延长, 平均长径比持续增大. 当辐照时间为7 min时, IAC-4微球被拉伸为棒状粒子, 其平均长径比可高达3.32.

关键词: 偶氮分子玻璃微球, 自组装机理, 临界水含量, 光致形变

Abstract:

Azo molecular glass microspheres with photoinduced deformation properties have attracted attention for fabricating anisotropic particles and other specific-shaped particles. In this work, we investigated the self-assembly of an azo molecular glass(IAC-4) material in tetrahydrofuran/water(THF/H2O) mixed solvents to form the colloidal spheres with uniform sizes in the dispersions as well as photoinduced deformation behavior of the formed IAC-4 microspheres. The intermediate states of self-assemblies were investigated via dynamic light scattering(DLS). The results showed that as the water content increased, the hydrodynamic radius(Rh) tended to increase to reach the maximum and then decreased gradually. The relationship between the critical water content(cwc) and initial concentration of IAC-4 in THF was proved to be consistent with the solubility of a solid solute in the binary mixed solvents, which indicated that IAC-4 underwent the transition from unsaturated state to a saturated state in the mixed solvents as the water content increased and then gradually aggregated to form the colloids in the dispersions. To test the photoinduced deformation property, the IAC-4 microspheres were obtained by separating the colloidal spheres from the dispersion and dried appropriately. Upon the irradiation with the linearly polarized laser beam(488 nm, 100 mW/cm2), the microspheres of IAC-4 showed rapid photoinduced deformation parallel to the polarized direction. After the irradiation for 1 min, IAC-4 microspheres were rapidly stretched into the ellipsoidal particles with the average axial ratio of 1.44. With the growth of the irradiation time, the average axial ratio further increased. Finally, the IAC-4 microspheres could evolve into the rod-like particles with the average axial ratio of 3.32 for the irradiation time of 7 min.

Key words: Microspheres of azo molecular glass, Mechanism of self-assembly, Critical water content, Photoinduced deformation

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