Exclusion of DC conductivity effect from dielectric loss spectrum using Kramers-Kronig relations for evaluation of slow dynamics of water molecules
Exclusion of DC conductivity effect from dielectric loss spectrum using Kramers-Kronig relations for evaluation of slow dynamics of water molecules
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DOI：
10.35848/1347-4065/ac6afe
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发表时间：
2022-06-01
影响因子：
1.5
通讯作者：
Shirakashi, Ryo
中科院分区：
文献类型：
--
作者：
Matsuura, Hiroaki;Shirakashi, Ryo
在含离子水体系的介电谱中，介电损耗谱受直流电导率σ的影响，它有时与水分子在亚GHz频率范围内的慢动力学相关的介电弛豫显著重叠。我们证明了一种基于Kramers-Kronig(KK)关系的实用方法，可以从实验获得的介电谱中排除直流电导率的贡献。超纯水和蛋白质水溶液(溶菌酶)光谱的KK变换实例表明了该方法的可行性。
In the dielectric spectroscopy of aqueous systems containing ions, the dielectric loss spectrum is affected by the contribution of the direct current (DC) conductivity sigma, which sometimes significantly overlaps the dielectric relaxations related to the slow dynamics of water molecules distributing in sub-GHz frequency range. We have demonstrated a practical procedure based on the Kramers-Kronig (KK) relations to exclude the contribution of DC conductivity from the experimentally obtained dielectric spectrum. Examples of the KK transform for the spectrum of ultrapure water and aqueous solution of protein (lysozyme) showed the feasibility of our method.