Study On Preparation Of Superhydrophobic Silicon Surface With Micro-column Structure And Tribological Properties

Superhydrophobic surface has been widely used in nature and industrial and agricultural production. Wettability, which is mainly governed by the surface microstructure and interface chemistry properties, is one of the most important indexes to measure the strength of the superhydrophobicity. It is difficult to create superhydrophobic surface by only changing the surface chemistry properties. So the surface morphology plays an important part in the preparation of superhydrophobic surface.This paper provides a new way to prepare the superhydrophobic surface. The micro-column arrays are fabricated by the inductively coupled plasma (ICP) on the monocrystalline silicon substrate. After self-assembled an octadecyltrichlorosilane (OTS) monolayer, the substrate achieves the superhydrophobicity. The energy dispersive Spectrometer (EDS), electronic tunnel scanning microscope (SEM),3-D laser confocal microscopy, atomic force microscope (AFM) and contact angle meter and other equipment are used to character the surface morphology, the composition and the wettability of the silicon only with micro-column arrays and only with self-assembled OTS monolayer, separately. The atomic force microscopy (AFM) is used to study the tribological properties of OTS monolayers. The main contents are summarized as follows:There is a transition from hydrophilic to hydrophobic after processing micro-column arrays on the silicon substrate. The hydrophobicity of silicon surface varies regularly with the size of the micro-column structure.Some of the silicon realize superhydrophobic by self-assembling OTS monolayer on the micro-column patterning substrate, the maximum contact angle is 157.35°. The hydrophobicity of silicon surface varies regularly with the size of the micro-column structure. The wetting state of water droplets on such silicon substrate is at Cassie state, namely, contains both liquid-solid contact and the liquid-vapor contact.The OTS monolayer on the silicon surface reduces the friction and adhesion, improves tribological properties of the silicon surface.