I would like to bond 3D printed PEG-DA 250 to a glass slide, (similar to creating soft-lithography devices with PDMS). Any suggestions on how to do this? I have tried an O2 plasma but it did nothing.
Treat your glass with a methacryloxypropyl silane and then UV bond it to you PEGDA structure using the residual crosslinker in the PEGDA. In order for the bond to be strong, the bonding surface of the PEGDA must be nearly as smooth as the glass. Happy Bonding.
I have ordered that and am waiting to receive the order. Planning on O2 plasma treatment, spin coating of 3-(Trimethoxysilyl)propyl methacrylate and then baking for 24 hr at 75C. Is this a similar treatment to what you would recommend?
Methoxy silanes are most often applied in an aqueous solution of about 1-2% silane and 10-20% ethanol. The water is an important component in the reaction that activates the silane. The concentration will influence the deposition rate and the organization of the coating (higher concentrations having a more disorganized coating). I have used any where from .2% to 5% of various silanes depending on the desired coating. I typically dip coat (5-20 minutes) when using aqueous coating solutions, rinse well, nitrogen dry, and then bake for an hour or so.
All of this is not to say that your proposed protocol will not work, there are many ways to use silanes that will provide reasonable results, but using the silane neat will decrease the ability of the molecules to organize themselves based on surface reactivity and decrease the number of covalent bonds to the substrate.
I typically keep the bakes between 60 and 80 Celsius. This helps keep some water present for the hydrolysis part of the reaction while helping to speed up the reaction rate. The other consideration for bake temperature is the substrate. I sometimes treat plastics that cannot tolerate high temperatures, e.g. polystyrene.