Investigation of the relationship between the wetting angle and the surface microprofile parameters

A brief overview of new approaches to characterizing the quality of surfaces with hydrophobic properties is given. These approaches are based on mathematical procedures involving a large amount of computation, including fractal methods. The relationship between the wetting angle of a hydrophobic surface and surface parameters such as roughness and fractal dimension of the profile has been studied. A model of a superhydrophobic surface is developed, its parameters are described, such as the effective hydrophobic wetting angle, the proportion of the solid phase of the surface in contact with the liquid, and the parameters of the hierarchical structure. It has been established that the use of nanostructured columns in the formation of a superhydrophobic surface, taking into account the hierarchical structure, makes it possible to significantly increase the values of the wetting edge angle. The dependence of the wetting edge angle on the fraction of the liquid-solid contact at the interface is determined, which is explained by the complication of the surface structure, and the relationship between the fraction of the solid phase and the fractal dimension is determined. It was found that when estimating the wetting edge angle, the relationship of the fractal dimension is significantly higher in comparison with the roughness parameters Ra and Rz. The correlation coefficients between the wetting angle and other parameters of the hydrophobic surface were determined using regression analysis. The results obtained can be used in the processing of measurement information in accordance with modern standards in the field of geometric characteristics of surfaces, including in the development of software for measuring parameters of hydrophobic surfaces.

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