I strongly recommend the following review paper which describes the thin-layer wicking method. This is the most reliable method for very fine powder. For any coarser powder the method described in the paper suggested by Vitalii is the most popular.
Paper: Application of thin-layer wicking method for surface free energy determination by E. Chibowski et al., Surface Innovations 5(1)(2017)9-20
I thank you very much. I did it based on your recommendations (Jaroslaw Drelich, Vitali,.....) and I thought this attached paper is also nice for powders.
I thank you in advance!
Article Evaluation of the wettability of mortar component granular m...