Department of Materials and Chemistry, Research Group Electrochemical and Surface Engineering (SURF), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America.
Sci Rep. 2017 Mar 22;7:45123. doi: 10.1038/srep45123.
Probing initial interactions at the interface of hybrid systems under humid conditions has the potential to reveal the local chemical environment at solid/solid interfaces under real-world, technologically relevant conditions. Here, we show that ambient pressure X-ray photoelectron spectroscopy (APXPS) with a conventional X-ray source can be used to study the effects of water exposure on the interaction of a nanometer-thin polyacrylic acid (PAA) layer with a native aluminum oxide surface. The formation of a carboxylate ionic bond at the interface is characterized both with APXPS and in situ attenuated total reflectance Fourier transform infrared spectroscopy in the Kretschmann geometry (ATR-FTIR Kretschmann). When water is dosed in the APXPS chamber up to 5 Torr (~28% relative humidity), an increase in the amount of ionic bonds at the interface is observed. To confirm our APXPS interpretation, complementary ATR-FTIR Kretschmann experiments on a similar model system, which is exposed to an aqueous electrolyte, are conducted. These spectra demonstrate that water leads to an increased wet adhesion through increased ionic bond formation.
在潮湿条件下探测混合系统界面的初始相互作用，有可能揭示真实技术相关条件下固/固界面的局部化学环境。在这里，我们表明，使用常规 X 射线源的常压 X 射线光电子能谱（APXPS）可用于研究水暴露对纳米级聚丙烯酸（PAA）层与天然氧化铝表面相互作用的影响。界面处羧酸离子键的形成通过 APXPS 和原位衰减全反射傅里叶变换红外光谱（ATR-FTIR Kretschmann）在 Kretschmann 几何结构中进行了表征。当在 APXPS 腔室中注入水至 5 托（~28%相对湿度）时，观察到界面处离子键数量的增加。为了证实我们的 APXPS 解释，对类似的模型系统进行了互补的 ATR-FTIR Kretschmann 实验，该系统暴露于电解质水溶液中。这些光谱表明，水通过增加离子键形成导致湿附着力增加。
