Interfacial slip modulated by water structure at negatively charged surface

The mechanism of interfacial slip is highly important in many applications. In this work, the interfacial slip length is calculated on the basis of atomic force microscopy measurements of different solutions on different surfaces. The results show that solutions with higher concentration, cations with stronger hydration capacity, and surfaces with higher hydrophobicity promote slip. In addition, we use sum frequency generation vibrational spectroscopy to directly identify the interfacial water structures. These results indicate that cations and surface characteristics strongly affect the interfacial water structures, suggesting that a lower amount of interfacial water and a higher proportion of disordered water increase the slip length. This work may provide some insights into the relationship between interfacial slip and interfacial structures from the perspective of water structures.