Evolution of wetting of a copper surface treated with nanosecond laser radiation

Laser treatment is a promising technique in the field of materials processing and design. Recently, the problem of controlled changes in the wetting properties of metals realized by the micro- and nanostructuring of surfaces has been actively investigated. In the present paper, the influence of the conditions of nanosecond laser processing on the wetting properties of a copper surface in the conditions randomly distributed hierarchical structure formation is investigated. Special attention is paid to the evolution of the contact angle over time. The mechanisms of changing the wetting properties over time are considered. It is shown that the overlap of laser spots is more important for copper surface hydrophobization than the laser fluence.