I've been wondering what keeps two pieces of wet paper together when in contact. Does water have any adhesive property? Or does it decompose something from the paper and creates some kind of glue? I would guess that it is the latter, but in this case are we dealing with a van der Waals bond? I assume that it can't be covalent or ionic, but is it? I've been trying to understand the van der Waals bonds and it sounds straight forward, but failing to understand this paper example makes me think that I didn't really understand it. Can anyone help me to understand it by using this paper example or another?
The prominent effect is due to capillarity, where a droplet of water inserted between two dry pieces of paper wets them and draws the sheets together as the water soaks into them. In answering the question this way we now have to account for why the water wets the surfaces of the cellulose fibers that the paper is made from. The most likely reason for that is hydrogen bonding.