Investigation of low frequency electrolytic solution behavior with an accurate electrical impedance method

Highlights: • An accurate low frequency impedance method for measuring strong electrolytes. • Better repeatability and accuracy compared to previous impedance methods. • Electrolytes appear a relaxation frequency at each peak value of dielectric loss. • The relaxation frequency increases in concentrated electrolytes. This paper reports the investigation of strong electrolytic solutions operated in low frequency regime through an accurate electrical impedance method realized with a specific microfluidic device and high resolution instruments. Experimental results show the better repeatability and accuracy of the proposed impedance method. Moreover, all electrolytic solutions appear the so-called relaxation frequency at each peak value of dielectric loss due to relaxing total polarization inside the device. The relaxation frequency of concentrated electrolytes becomes higher owing to the stronger total polarization behavior coming from the higher conductivity as well as the lower resistance in the electrolytic solutions.