How does the silver nucleate on glass in Tollen's reagent mirroring? I want to know the exact mechanism for how silver would start to grow during a mirroring with Tollen's reagent. I've made two pictures to illustrate how I see the nucleation/growth process of silver on silica:


As you can see, I didn't draw any chemical bonds, because I think that the silver adherence is due to Van Der Waals forces. Am I correct? If that is the case, then I believe a place with high permanent polarisation would be better suited for the nucleation of silver.
Now, let's follow the logic. We have a greater electronegativity difference between $\ce{O}$ and $\ce{Si}$ ($3.44 - 1.90 = 1.54$) than between $\ce{O}$ and $\ce{H}$ ($3.44 - 2.2 = 1.24$).
For the upper oxygen, assuming an angle of 109 degrees, you get a total dipole moment of: $2(1.54)\cos\left(\frac{109}{2}\right) = 1.79$
For the lower oxygen with the bonded hydrogen, assuming an angle of 120 degrees , you would get a total dipole moment of: $1.54 + 1.24 = 2.78$
(please tell me if I'm wrong to assume a straight line!)
This would mean that you have a greater accumulation of electrons at the bottom oxygen, which would favor Van Der Waals attraction (Debye interaction, I guess, since you have a permanent dipole and an induced dipole). This, in turn, would mean that it would be a better nucleation site.
If you make a surface treatment using silane groups, I believe you promote the presence of $\ce{OH}$ groups at your silica surface, though I'm unsure about this. I do know that it makes better silver mirroring though. I've made another drawing:

Following my logic, this one is wrong in many way. First of all, I drew angles on the $\ce{Si-O-H}$ bonds, which I didn't draw on my first pictures. Secondly, the silver is not even near the oxygen atoms, which I believe are the nucleation points.
I'm confused, could you please point out to me where I'm right or wrong in my logic/knowledge?
Mainly:

Is there a bond forming between the silica surface and the silver? Or is there only Van Der Waals (Debye) attraction?
Is my depiction of nucleation &amp; growth correct (for the first two pictures)?
Is my logic regarding the electronegativity correct?
Is my logic of &quot; higher total electronegativity difference, hence better nucleation site&quot; correct? (assuming I'm right about the Van Der Waals Forces)
Is my depiction of silanisation correct?
Am I right to say that the higher abundance of surface $\ce{OH}$ groups by silanisation implies better nucleation?
Could I do the same when using a strong acid on my glass surface?
"If you make a surface treatment using silane groups, I think that you promote the presence of OH groups at your silica surface". This is NOT correct. You siliconize glass to cap the free SiOH groups

2 silica_Si-OH + n SiCl2Me2 + HO-Si_silica -> silica_Si-[O(SiMe2)]$_n$-O-Si_silica. As a result you decrease the number of active OH groups and make it highly non-polar. 

Before siliconization silica is surrounded by a hydration sphere. Ag$^+$ can bind it well, but we need to precipitate neutral Ag. In case of non-siliconized glass we have two effects:

(1)  It is easier for silver to grow on the surface that already has a silver nano-crystal
(2) Before treatment glass have inhomogeneities, so nucliation in some places is heavily favored.

Both effects are negated by siliconization.



Note that I didn't account for surface charges which change as a result of siliconization and might play a role.