P.S. Нашёл это утверждение про "смачивания недостаточно":
https://www.adhesives.org/adhesives-sealants/science-of-adhesion/why-does-an-adhesive-bond писал(а):
The degree of wetting, which among other things is determined by the surface tension of the adhesive and substrate, is hence a criterion for the quality of the adhesion. The approaching of atoms is however only a prerequisite for the formation of adhesive forces. The determining factor for the actual adhesion is the accessibility of and number of physically or chemically active structures on the substrate surface and in the adhesive.
The wetting of the substrate surface by the liquid adhesive is necessary for adhesion, but this alone is not sufficient. Good wetting alone does not necessarily guarantee the desired good long-term adhesion of the adhesive to the surface.
Consider, for example, high-grade steel: Although this has a high surface tension it can be easily wetted. However, due to its passive character (poor bonding properties) there is only relatively poor adhesion of adhesive to the surface.
Что это за "физически и химически активные структуры", которые должны быть на поверхности субстрата или в клее, и как они работают?