Molecular structure of surface active salt solutions: photoelectron spectroscopy and molecular dynamics simulations of aqueous Tetrabutyl-Ammonium Iodide
Molecular structure of surface active salt solutions: photoelectron spectroscopy and molecular dynamics simulations of aqueous Tetrabutyl-Ammonium Iodide
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表面活性盐溶液的分子结构：四丁基碘化铵水溶液的光电子能谱和分子动力学模拟
DOI：
10.1021/jp0493531
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发表时间：
2004
影响因子：
3.3
通讯作者：
P. Jungwirth
中科院分区：
文献类型：
--
作者：
B. Winter;R. Weber;P. Schmidt;I. Hertel;M. Faubel;L. Vrbka;P. Jungwirth
报道了表面活性四丁基碘化铵(TBAI)在水溶液中的光电子测量和分子动力学(MD)模拟。利用6μm直径液体射流，研究了光子能量为100 eV的光电子能谱。与相同盐浓度的NaI水溶液相比，TbAI盐在溶液表面的表面活性由I-(4d)信号的显著增加(×70)所证明。通过碘化物光电子发射信号的增长，作为盐浓度的函数，提出了分离单层的完成。我们的实验表明，碘化物在TBAI和NaI水溶液中的电子结合能是相同的，这与盐的浓度无关。任何特征的零或很小的光谱位移，包括低能截止，都表明垂直于表面的TBA+和I-离子对没有形成偶极，这与模拟的离子密度分布是一致的。波..。
We report photoelectron measurements and molecular dynamics (MD) simulations with a polarizable force field of surface-active tetrabutylammonium iodide (TBAI) in aqueous solution. Photoemission is studied for a photon energy of 100 eV, using a 6-μm-diameter liquid jet. Surfactant activity of the TBAI salt at the solution surface is proved by a dramatic (×70) increase of the I-(4d) signal, as compared to that of a NaI aqueous solution for identical salt concentrations. Completion of the segregation monolayer is suggested through the growth of the iodide photoelectron emission signal, as a function of the salt concentration. Our experiments reveal identical electron binding energies of iodide in TBAI and NaI aqueous solutions, which are independent of the salt concentration. Zero or very small spectral shifts of any feature, including the low-energy cutoff, suggest that no dipole is formed by TBA+ and I- ion pairs perpendicular to the surface, which is in accord with the simulated ionic density profiles. Bo...