What is the mechanism of functionalisation of nanoparticle using long chain alcohols How can long chain alcohols(not thiols) be functionalised on the surface of silver or gold nanoparticles? 

I have read in an article that Polyvinyl alcohol is used as a capping agent for silver nanoparticle synthesis, but what is the mechanism for that? 

What type of bonds form between nanoparticle and the long chain alcohol(covalent or ionic)? 

Is there any relationship between chain length of alcohols(or thiols) to the functionalisation of nanoparticles?
The longer the alykylchains, the more likely you can form self-assembled monolayers (SAMs), which will hold themselves together by covalent interactions between chains.  The nanoparticle analog would be miceles.

However, alcohols are a fairly weak ligand for silver, so I'm not sure this is feasible.  SAMs are known to form on silver with carboxylate ligands.