离子
电解质
表面电荷
多收费
材料科学
吸附
分析化学(期刊)
饱和(图论)
单层
化学物理
化学
物理
电极
物理化学
热力学
纳米技术
色谱法
组合数学
功率(物理)
有机化学
数学
电池(电)
作者
Jens Pittler,Wei Bu,David Vaknin,Alex Travesset,Duncan J. McGillivray,Mathias Lösche
标识
DOI:10.1103/physrevlett.97.046102
摘要
Anionic dimyristoylphosphatidic acid monolayers spread on LaCl3 solutions reveal strong cation adsorption and a sharp transition to surface overcharging at unexpectedly low bulk salt concentrations. We determine the surface accumulation of La3+ with anomalous x-ray reflectivity and find that La3+ compensates the lipid surface charge by forming a Stern layer with approximately 1 La3+ ion per 3 lipids below a critical bulk concentration, ct approximately 500 nM. Above ct, the surface concentration of La3+ increases to a saturation level with approximately 1 La3+ per lipid, thus implying that the total electric charge of the La3+ exceeds the surface charge. This overcharge is observed at approximately 4 orders of magnitude lower concentration than predicted in ion-ion correlation theories. We suggest that transverse electrostatic correlations between mobile ions and surface charges (interfacial Bjerrum pairing) may contribute to the charge inversion.
科研通智能强力驱动
Strongly Powered by AbleSci AI