高等学校化学学报 ›› 2014, Vol. 35 ›› Issue (4): 689-694.doi: 10.7503/cjcu20140096

• 研究论文: 无机化学 • 上一篇    下一篇

孔道型微孔和介孔分子筛的改性及超级绝热性能

张涛, 董雪, 张宗弢()   

  1. 吉林大学化学学院, 长春 130012
  • 收稿日期:2014-01-29 出版日期:2014-04-10 发布日期:2014-03-11
  • 作者简介:联系人简介: 张宗弢, 男, 博士, 教授, 主要从事无机纳米材料研究. E-mail: zzhang@jlu.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 20841003, 20741001)资助

Surface Modification of Microporous and Mesoporous Molecular Sieves and Their Super Insulation Properties

ZHANG Tao, DONG Xue, ZHANG Zongtao*()   

  1. College of Chemistry, Jilin University, Changchun 130012, China
  • Received:2014-01-29 Online:2014-04-10 Published:2014-03-11
  • Contact: ZHANG Zongtao E-mail:zzhang@jlu.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.20841003, 20741001)

摘要:

在水热体系中合成了具有规则孔道结构的微孔分子筛ZSM-5和介孔分子筛MCM-41, SBA-15, MAS-5, 通过改变材料表面的电性对介孔材料进行了化学修饰. 采用X射线衍射(XRD)和扫描电子显微镜(SEM)对样品的结构、 形貌进行了表征; 通过氮气吸附-脱附测试了产物的比表面积, 采用BJH法计算孔分布和孔容; 将制得的样品压制成绝热材料后, 进行导热性质测定. 常温(25 ℃)常压下, 有序介孔分子筛MCM-41的导热系数为0.038 W·m-1·K-1, 具有少量微孔结构的MAS-5的导热系数为0.035 W·m-1·K-1, 二者均为超级绝热材料. 材料经改性后, 绝热性能有所提高: MCM-41的导热系数降至0.028 W·m-1·K-1, MAS-5的导热系数降至0.017 W·m-1·K-1. 结合纳米介孔材料导热理论模型进行分析, 发现纳米孔绝热材料的孔径越小, 孔隙率越大, 绝热性能好; 介孔分子筛的导热系数与其孔壁厚度、 孔径大小以及孔隙率有关.

关键词: 介孔分子筛, 微孔分子筛, 纳米绝热材料, 热导

Abstract:

Microporous aluminosilicates ZSM-5, ordered mesostructured materials MCM-41, SBA-15, MAS-5 were synthesized in hydrothermal system. Then, these nanoparticles were electrostatically modified with linear cationic polymer agent. The as-synthesized samples were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and N2 adsorption-desorption isotherms. Surface area was determined by Brunauer-Emmett-Teller(BET) equation; pore size distribution and pore volume were measured by Barrett-Joyner-Halonda(BJH) method. Samples for thermal conductivity measurements were prepared by pressing powders into disks. The thermal conductivity of well-ordered mesoporous MCM-41 is as low as 0.038 W·m-1·K-1. The thermal conductivity of MAS-5 is 0.035 W·m-1·K-1. The thermal conductivities of modified MCM-41 and MAS-5 deereased to 0.028 and 0.017 W·m-1·K-1 respectively. Theoretical analysis and experimental results simultaneously explain that materials with smaller pore size or higher porosity demonstrate better properties of thermal insulation; thermal conductivities of ordered mesoporous materials associate with wall thickness, pore size and porosity.

Key words: Mesoporous molecular sieve, Microporous molecular sieve, Nano thermal insulation material, Thermal conductivity

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