Isoelectric point pH, mV, for a metal oxide nanopowder

I'm trying to make a solution of $\ce{TiO2}$ that will coat stuff in as dense a monolayer as possible. To do so, I'm using nano sized $\ce{TiO}$ particles and trying to get them to get as close to each other as possible. From what I understand, the way to get these little guys to get close to each other is to get the solution to its isoelectric point thereby eliminating any repulsion caused by charge.

So: what pH should I set my water and $\ce{TiO2}$ powder at to attain my isoelectric point? I ask because finding such a number has proven to be elusive. I've found pH numbers from 3.8 to 9 to attain isolectricity for such a solution. Does anyone have any experience with the stuff such that a true pH to attain isoelectricity revealed?

In addition, the meter to which I have access for pH also measures mV. Is there a way to relate mV to the isoelectric point? Is it as obvious as it seems i.e. keeping adding an acid until my little meter says that mV equals zero? Or is there something more going on (there always is)? Are this mV value and the isoelectric point even related?

Thanks for any help!