All this is way above me. I am a dentist and use silane as a coupling agent to coat porcelain restorations prior to bonding them to teeth with resin cements to enhance the bond. Using it with the emulsion to coat glass plates is probably works in a similar fashion. As a dental product silane is over $50 for 12ml.

Just thought this may be of interest.

http://www.jeffreyglasser.com/