Molecular structure of liquids at solid surfaces

固体表面的液体通常形成分子层状结构。即使对于简单的有机液体，如短链烷烃或醇，也会形成多达五个分子层。关于这种分层的实验信息是从表面力测量中获得的。在表面力实验中，测量了在封闭的液体间隙上接近两个光滑固体表面所需的力。在这个项目中，计划使用原子力显微镜和自制的粒子相互作用装置来测量表面力。作为液体醇、烷烃和其他简单液体(相对分子质量低于100g/mol，熔点低于O°C)进行了研究。解决的一个重要问题是，液体是在孤立的表面显示层状结构，还是仅在受限空间显示层状结构(这在表面力实验中是不可避免的)。因此，我们压入不同的衬底(云母、氧化硅、金表面的硫醇分子膜等无机层状材料)和针尖材料(氮化硅、氧化硅、金表面的硫醇单层膜)进行实验。此外，尖端的半径是系统变化的，保持了材料性质的恒定。

Liquids at solid surfaces often form a molecularly layered structure. Even for simple organic liquids such as short-chain alkanes or alcohols up to five molecular layers are formed. Experimental information about this layering is obtained from surface force measurements. In a surface force experiment the force required to approach two smooth solid surfaces over a closing liquid gap is measured. In this project surface force measurements using an atomic force microscope and a homebuilt particle interaction apparatus are planned. As liquids alcohols, alkanes and other simple liquids (molecular weight below 100 g/mol, melting point below O°C) are studied. One significant question addressed is whether the liquids show the layered structure at isolated surfaces or only in confined spaces (which is inevitable in a surface force experiment). Therefore, we indent to do experiments with different substrates (mica, silicon oxide, thiol mololayers on gold, other inorganic layered materials) and tip materials (silicon nitride, silicon oxide, thiol monolayers on gold). In addition, the radius of the tip is systematically varied keeping the material properties constant.