Dielectric properties of water and NaCl solutions investigated by terahertz time-domain spectroscopy

Abstract

We have used Terahertz time-domain spectroscopy(TDS) to investigate the dielectric properties of water and water solutions of containing different ions. The complex permittivity of NaCl solutions, for different concentrations of ions, was obtained by attenuated total reflection(ATR) method. We have observed that, when increasing o ion concentration, the real part and imaginary part of the permittivity are increased. Furthermore, we also calculate the dielectric constant of ionic aqueous solutions with different concentrations based on molecular dynamics method. The simulation method, based on Newton mechanics, can estimate the dielectric constant of liquid substances without the experimental limitation.