化学学报 ›› 2012, Vol. 70 ›› Issue (16): 1721-1724.DOI: 10.6023/A12040163 上一篇    下一篇

研究论文

光交联Pickering乳液中的粒子稳定剂制备胶体体微胶囊

王朝阳, 宁印, 陈云华, 童真   

  1. 华南理工大学材料科学研究所 广州 510640
  • 收稿日期:2012-05-01 出版日期:2012-08-28 发布日期:2012-07-02
  • 通讯作者: 王朝阳
  • 基金资助:
    项目受国家重点基础研究发展计划(973, No. 2012CB821500)、国家自然科学基金(No. 50973034)及中央高校基本科研业务费资助.

Preparation of Colloidosome Microcapsules Based on Particle Stabilized Photo-Crosslinkable Pickering Emulsions

Wang Chaoyang, Ning Yin, Chen Yunhua, Tong Zhen   

  1. Research Institute of Materials Science, South China University of Technology, Guangzhou 510640
  • Received:2012-05-01 Online:2012-08-28 Published:2012-07-02
  • Supported by:
    Project supported by the National Basic Research Program of China (973 Program, No. 2012CB821500), the National Natural Science Foundation of China (No. 50973034) and the Fundamental Research Funds for the Central Universities.

研究了光敏性聚合物刷修饰二氧化硅纳米粒子的制备及其乳化行为, 提供了一种制备新颖“胶体体”微胶囊的方法. 首先, 在二氧化硅纳米粒子表面引入原子转移自由基聚合(ATRP)引发剂分子, 通过表面引发ATRP得到含有香豆素侧基聚合物刷光敏性的纳米二氧化硅粒子(SiO2-PMMA-PCMA); 然后, 以该粒子为乳化剂制备油包水型的皮克林乳液; 最后, 在紫外光的照射下引发香豆素侧基的交联反应从而得到“胶体体”微胶囊. 结果表明, 香豆素单体7-(2-甲基丙烯酰乙氧基)-4-甲基香豆素(CMA)和SiO2-PMMA-PCMA在紫外光作用下都可以发生交联反应, 以SiO2-PMMA- PCMA纳米粒子作乳化剂可以制备稳定的皮克林乳液, 光交联后得到的“胶体体”微胶囊的平均粒径约为170 μm.

关键词: 胶体体, 皮克林乳液, 表面引发原子转移自由基聚合, 聚合物刷, 光交联

In this work, we studied the preparation and emulsification behavior of nanoparticles with photo-sensitive polymer brushes and presented a method for the preparation of novel colloidosome microcapsules based on single Pickering emulsion template, which is stabilized by surface-modified silica nanoparticles with photodimerizable coumarin group. Firstly, silica nanoparticles were self-made by using a stöber method with a diameter of about 180 nm, following aminated by 3-aminopropyltriethoxysilane (APS) and further modified by 2-bromo-2-methylpropionyl bromide, endowing these nanoparticles with ATRP-initiator reactive group. After that, silica nanoparticles with photo-sensitive polymer brushes (SiO2- PMMA-PCMA) were obtained through graft reaction of methyl methacrylate (MMA) and 7-(2-methacryloyloxyethoxy)-4-methylcoumarin (CMA) monomers (with a molar fraction of 4∶1) onto silica nanoparticles by surface-initiated atom transfer radical polymerization (SI-ATRP) method. Here, CMA was synthesized via a two-step method and was detected by UV-visible spectrophotometer. Secondly, the as-prepared hydrophobic SiO2-PMMA-PCMA nanoparticles were dispersed in 2 mL of toluene with a ultrasonic for 5 min (with an interval of 30 s per min), then 0.5 mL of deionized water was rapidly added, afterwards, water-in-oil type Pickering emulsions were prepared by hand-shake for 3 min. Finally, colloidosome microcapsules were produced through cross-linking reaction of the coumarin group of CMA initiated by UV irradiation, in this step, the SiO2-PMMA-PCMA nanoparticles were locked. The average size and size distribution of as-synthesized Pickering emulsion droplets and colloidosomes were observed with an optical microscope. The results show that both CMA and SiO2-PMMA-PCMA nanoparticles can be initiated to cross-link through the dimerization of the coumarin groups of CMA from different SiO2-PMMA-PCMA nanoparticles via UV irradiation, the dimerization rate of CMA reached about 80% in 6 min and the UV absorption peak of coumarin group of SiO2-PMMA-PCMA nanoparticles was blue-shifted. Besides, the Pickering emulsion droplets can be stored for a long time without breaking up and the average size of as-produced colloidosome microcapsules were about 170 μm. In theory, this method can be scaled up to produce large quantity of colloidosomes.

Key words: colloidosomes, Pickering emulsions, SI-ATRP, polymer brushes, photo-crosslinkable