电喷水纳米滴的表面电荷:一个分子动力学研究研究
1Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada.
Journal of the American Chemical Society
|August 12, 2010
概括
电子喷射电离 (ESI) 纳米滴中的过量电荷载体位于内部,而不是表面. 水分子的两极化产生表面电荷效应,验证了ESI表面电荷范式.
科学领域:
- 物理化学 物理化学
- 计算化学计算化学
- 表面科学是一门学科.
背景情况:
- 含有过多电荷载体的水性纳米滴对于电子喷射电离 (ESI) 非常重要.
- 这些电荷载体 (离子) 在纳米滴中的位置受到争议,通常假定表面封闭.
- 溶解效应可能使表面局部化对离子来说在能量方面不利.
研究的目的:
- 在雷利极限附近的含有离子的水纳米滴中调查电荷载体位置.
- 调和模拟离子位置与ESI中已建立的表面电荷范式之间的明显矛盾.
主要方法:
- 利用分子动力学模拟来建模含有Na(+) 的水纳米滴.
- 执行静电映射以确定纳米滴中的电荷分布.
- 分析了水分子的定向偏振效应.
主要成果:
- 模拟显示,Na(+) 离子位于纳米滴中,而不是在表面.
- 尽管内部离子位置,静电映射证实过量的电荷存在于滴水表面.
- 水分子的两极分化,特别是在水滴外围,解释了表面电荷效应.
结论:
- 在ESI中表面电荷范式是有效的,但不需要离子在液体/蒸汽界面.
- 内部的离子溶解和外部的水双极方向共同保持表面电荷.
- 这一发现澄清了ESI过程中带电纳米滴的基本行为.
更多相关视频
相关概念视频
The Electrical Double Layer
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...
Electrochemical Systems
Electrochemical systems provide a fascinating insight into the dynamic interplay of charged species within various phases. One notable example is the interaction between a membrane permeable to K⁺ ions but not to Cl⁻ ions, separating an aqueous KCl solution from pure water. As K⁺ ions diffuse through the membrane, they generate net charges on each phase, leading to a potential difference between them.Similarly, when a piece of Zn is immersed in an aqueous ZnSO₄ solution, the Zn metal, composed...
Van der Waals Interactions
Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions between particles with permanent, partial, or temporary charges. The intermolecular forces between neutral atoms and molecules are ion–dipole, dipole–dipole, and dispersion forces, collectively known as van der Waals forces.Polar molecules have a partial positive charge on one end and a partial negative charge on the other end of the molecule,...
Electrospray Ionization (ESI) Mass Spectrometry
Higher molecular weight biomolecules are nonvolatile compounds that may decompose before ionizing or vaporizing during mass analysis with conventional electron impact ionization methods. Accordingly, electrospray ionization (ESI) is the favored method for vaporizing and ionizing biomolecules as it circumvents rapid fragmentation and enables the recording of mass signals for the entire biomolecule.
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...


