Relationship between surface morphology and wetting characteristics of coal based on optical profilometer and atomic force microscope

In order to explore the influence of different scale morphology characteristics of hydrophobic coal surface on its wetting characteristics, optical profilometer and atomic force microscope were used. The three-dimensional surface topography, surface profile curve, surface roughness, pore structure and fractal characterization of 10 rough samples of different scales were carried out by these instruments. Combined with the contact angle measurement experiment, the relationship between the important structural parameters of the surface morphology and the wetting characteristics was obtained, and the influence mechanism of the wetting characteristics was revealed. It is found that the smaller the surface roughness of hydrophobic coal is, the better the surface wettability is. The AFM experiment shows that the smaller the surface porosity of the surface hydrophobic coal body, the better the wettability. The smaller the fractal dimension of coal surface pore structure is, the better the wettability is.