物理化学学报 >> 2011, Vol. 27 >> Issue (11): 2521-2527.doi: 10.3866/PKU.WHXB20111121

热力学,动力学和结构化学 上一篇    下一篇

高时空分辨率研究海盐液滴快速风化过程

仝海杰1, 钱正纲1, REID Jonathan P.2, 张韫宏1   

  1. 1. 北京理工大学物理化学研究所, 簇科学重点实验室, 北京 100081;
    2. School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
  • 收稿日期:2011-06-02 修回日期:2011-08-31 发布日期:2011-10-27
  • 通讯作者: 张韫宏 E-mail:yhz@bit.edu.cn
  • 基金资助:

    国家自然科学基金(20933001, 20873006)资助项目

High Temporal and Spatial Resolution Measurements of the Rapid Efflorescence of Sea Salt Droplets

TONG Hai-Jie1, QIAN Zheng-Gang1, REID Jonathan P.2, ZHANG Yun-Hong1   

  1. 1. Institute of Chemical Physics, Key Laboratory of Cluster Science, Beijing Institute of Technology, Beijing 100081, P. R. China;
    2. School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
  • Received:2011-06-02 Revised:2011-08-31 Published:2011-10-27
  • Contact: ZHANGYun-Hong E-mail:yhz@bit.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20933001, 20873006).

摘要: 以高速摄像仪与显微拉曼光谱联用研究聚四氟(疏水)乙烯基底和石英(亲水)基底上的单个海水液滴的快速风化过程. 海水液滴风化的形貌图像达到毫秒时间分辨率和微米空间分辨率. 通入干氮气后海水液滴在石英基底上发生快速风化过程, 首先析出Na2Ca5(SO4)6·3H2O和Na2xCa6-x(SO4)6·3H2O (0<x<1)晶体, 然后析出NaCl 晶体, 最后析出KMgCl3·6H2O晶体. 我们发现在快速降低湿度的过程中析出钙钠复盐, 在缓慢降低湿度的过程中析出CaSO4·2H2O, 并已经确定各种结晶产物的位置以及Na2Ca5(SO4)6·3H2O和CaSO4·2H2O两种晶体的生长速率, 并在聚四氟乙烯基底上观察到中空结构的海盐颗粒.

关键词: 海盐, 高速摄像, 拉曼光谱, 风化, 相对湿度

Abstract: The rapid efflorescence of individual seawater droplets on polytetrafluoroethylene (PTFE, hydrophobic) and quartz (hydrophilic) substrates was investigated using a high-speed camera for imaging and micro-Raman spectroscopy to spatially resolve the particle composition. The morphology of the evaporating sea salt particles was captured using millisecond time resolution and micrometer spatial resolution. Upon rapid desiccation with dry N2 on a quartz substrate, Na2Ca5(SO4)6·3H2O and Na2xCa6-x(SO4)6· 3H2O (0<x<1) crystallized first followed by NaCl and finally KMgCl3·6H2O. We determined the formation behavior of the mixed sodium-calcium salts as crystallization products during the quick desiccation process and CaSO4·2H2O during the slow desiccation process. In addition, the crystallization location of different crystal products were identified and the growth speed of Na2Ca5(SO4)6·3H2O crystal was compared with that of CaSO4·2H2O crystal. Moreover, sea salt particles with a hollow structure were observed on the PTFE substrate at the end of the quick efflorescence process.

Key words: Sea salt, High-speed photography, Raman spectroscopy, Efflorescence, Relative humidity

MSC2000: 

  • O642