Martin-Jimenez Daniel, Garcia Ricardo
Materials Science Factory, Instituto de Ciencia de Materiales de Madrid, CSIC , c/Sor Juana Ines de la Cruz 3, 28049 Madrid, Spain.
J Phys Chem Lett. 2017 Dec 7;8(23):5707-5711. doi: 10.1021/acs.jpclett.7b02671. Epub 2017 Nov 9.
Force microscope provides atomically resolved images of surfaces immersed in a liquid. The presence of different chemical species in the interface (cations, anions, water, neutral atoms) complicates the adscription of the observed features to a given species. We develop a 3D atomic force microscopy method to identify the cations adsorbed on a mica surface from a potassium chloride solution. The method is based on measuring the peak value of the attractive force within the Stern layer. The maximum of the attractive force shows site-specific variations. The positions with the highest attractive force values are associated with the presence of adsorbed potassium ions, while the other positions are associated with a local depletion of the hydration layer. This criterion provides a surface coverage of K cations that is consistent with the one reported by other techniques.
力显微镜可提供浸入液体中的表面的原子分辨图像。界面中存在不同的化学物种（阳离子、阴离子、水、中性原子），这使得将观察到的特征归因于特定物种变得复杂。我们开发了一种三维原子力显微镜方法，用于识别从氯化钾溶液中吸附在云母表面的阳离子。该方法基于测量斯特恩层内吸引力的峰值。吸引力的最大值显示出位点特异性变化。吸引力值最高的位置与吸附钾离子的存在有关，而其他位置与水化层的局部耗尽有关。该标准提供的钾阳离子表面覆盖率与其他技术报告的一致。
