Mierzwiński Dariusz, Walter Janusz, Wanat Dominika
Faculty of Materials Engineering and Physics, Cracow University of Technology, 24 Warszawska Street, 31-155 Kraków, Poland.
Materials (Basel). 2023 Jul 24;16(14):5190. doi: 10.3390/ma16145190.
The porous geopolymer has been tested for its content of water using impedance methods. The pores of the material were filled with distilled water using a desiccator and a vacuum pump. An analysis of differential scanning calorimetry (DSC) was carried out in the next step to check the content of water, porosity and approximate value of specific heat of the geopolymer. Additionally, mercury porosimeter has been used for checking the porosity. The geopolymer material characterized in this way was subjected to impedance tests aimed at developing a quick method for assessing the water content in the material. Impedance measurements have been realized on an electrochemical workstation applying a 50 mV non-destructive amplitude of the potential and a frequency range of 1 Hz to 100 kHz. Change in the module of impedance and the phase shift angle were measured while the material was dried out. Significant differences were observed. The obtained graphs were simulated using a schematic model consisting of constant phase elements (CPEs) and a resistor (R). These values showed mechanisms of charge conduction. A simple method for assessing the water content of a porous geopolymer has been proposed in this paper. The real and imaginary impedance values were shown in Nyquist graphs. These graphs have characteristic maxima that move according to a linear equation with decreasing water content. Changes in Nyqiust charts are clearly visible even with small changes in the water content of the material and can be very useful for assessing it.
已采用阻抗法对多孔地质聚合物的含水量进行了测试。使用干燥器和真空泵将蒸馏水填充到材料的孔隙中。下一步进行差示扫描量热法（DSC）分析，以检查地质聚合物的含水量、孔隙率和比热容的近似值。此外，压汞仪已用于检查孔隙率。以这种方式表征的地质聚合物材料进行了阻抗测试，旨在开发一种快速评估材料中含水量的方法。在电化学工作站上进行了阻抗测量，施加50 mV的无损电位幅度和1 Hz至100 kHz的频率范围。在材料干燥过程中测量了阻抗模量和相移角的变化。观察到了显著差异。使用由恒相元件（CPE）和电阻器（R）组成的示意图模型对获得的图形进行了模拟。这些值显示了电荷传导机制。本文提出了一种评估多孔地质聚合物含水量的简单方法。实部和虚部阻抗值显示在奈奎斯特图中。这些图具有特征最大值，随着含水量的降低，这些最大值根据线性方程移动。即使材料含水量有微小变化，奈奎斯特图中的变化也清晰可见，并且对于评估含水量非常有用。
