【摘要】 由于双电层结构对离子在微纳米通道中的输运特性至关重要,为了探究离子相关性对表面双电层结构在混合溶液中的影响,利用表面力仪测量了两云母表面在相同离子强度下(10^-4 mol/L)不同体积分数时LaCl₃/KCl及LaCl₃/MgCl₂混合电解质溶液中的表面相互作用力.研究结果表明:当溶液中的La³⁺离子达到某一临界浓度时云母的表面电荷发生倒置,一价离子的加入对表面电荷倒置的影响较小,而二价离子对表面电荷倒置有一定的抑制作用.运用离子间的强相关理论分析了离子相关性对云母表面电荷倒置的影响机理.研究结果对理解离子相关性在双电层结构、表面电荷特性和离子输运方面的影响有重要意义.更多还原

【Abstract】 As the structure of electrical double layer（EDL） is crucial for the transport properties of ions in micro/nanochannels, to demonstrate the effects of the ion-ion correlations on EDL structures in mixture electrolyte solutions, the interaction forces between two mica surfaces immersed in different volume fractions of LaCl₃/KCl and LaCl₃/MgCl₂ mixture solutions with a total ionic strength of 10^-4 mol/L were measured using a surface forces apparatus（SFA）. The results reveal that the surface charge of mica surfaces can be inversed at a critical concentration of La³⁺ ions in electrolyte solutions, due to the correlations between La³⁺ ions. The addition of monovalent has negligible effects on ion-ion correlations, while the charge inversion was slightly suppressed by introducing the divalent ions. The mechanism of charge inversion in mixture electrolyte solutions was analyzed based on the strongly correlated liquid（SCL） theory. These findings provide implications for understanding the effects of ion-ion correlations on EDL structures, surface charge properties, and ion transportation.更多还原