Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (5): 1143-1150.doi: 10.3866/PKU.WHXB201602184

• ARTICLE • Previous Articles     Next Articles

Study of the Hydrated Structure of KCl and NaCl Mixed Solutions Using X-ray Diffraction and Raman Spectroscopy

Jun-Sheng YUAN1,3,*(),Zi-Yu LIU2,3,Fei LI1,3,Shen-Yu LI1,3   

  1. 1 School of Marine Science and Engineering, Hebei University of Technology, Tianjin 300130, P. R. China
    2 School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, P. R. China
    3 Engineering Research Center of Seawater Utilization Technology of Ministry of Education, Tianjin 300130, P. R. China
  • Received:2015-12-11 Published:2016-05-07
  • Contact: Jun-Sheng YUAN E-mail:jsyuan2012@126.com
  • Supported by:
    the Basic Research Project of Applied Basic Research Plan of Hebei Province, China(13963103D);Program for Changjiang Scholars and Innovative Research Team in University, China(IRT14R14);National Key Technology R & D Program, China(2015BAB09B00)

Abstract:

Research on the hydrated structure of KCl and NaCl mixed solutions with a concentration range between 0 and 26% was conducted using X-ray diffraction and Raman spectroscopy at 25 ℃. Their reduced structure functions, F(Q), and reduced pair distribution functions, G(r), obtained from X-ray diffraction indicate that compared with Na+, the hydration numbers and shell radii of the hydrated K+ ions are larger. This explains why the solubility of NaCl is higher than that of KCl at 25 ℃. According to the Raman spectroscopy, the tetrahedral hydrogen bonds of water molecules will be destroyed with the increase in KCl concentration and the decrease in NaCl concentration. The extent of the bond destruction has systematic variations; for example, increasing at first and then decreasing. These results show that the destruction of the hydrogen bond structure resulting from Na+ is more serious than from K+. Also, with the appropriate K+ content in the NaCl solution, Na+ will behave as a structure breaker instead of a structure maker, which enhances the destructiveness of the solution structure.

Key words: X-ray diffraction, Raman spectroscopy, Potassium chloride, Sodium chloride, Solution structure

MSC2000: 

  • O641