Casting a Film on Glass

If you cannot cast a film on water, another way is to cast it on a glass plate. This way can be a little more difficult than casting on water because sometimes the film gets stuck to the glass. This is usually because the glass is not completely smooth, or the polymer adheres to the glass. It is very important that the film be removed, because glass blocks IR light, and you will be unable to aquire a spectrum. If the film will not easily peel away from the glass, sometimes soaking the slide in water will free it. However, if you do that, why not just cast the film on water, if you can?

Anyway, enough talk about the film. Let's make it!

1. DO EVERYTHING IN THE HOOD!
2. Disolve your polymer in an appropriate solvent.
   • Choose a volatile solvent (Why?)
   • Make the solution fairly concentrated (Why?)
3. Get a smooth, flat piece of glass (watch glass, petri dish, bottom of a beaker, microscope slide).
4. Using a disposable pipette, place some of your solution on the glass (don't let it run off the edges)
5. Let the solvent evaporate slowly. To control rate of solvent loss, you might want to partially cover the sample with a petri dish or watchglass
6. Remove film from surface of glasslet dry

Sometimes a film is to brittle to cast a film which may be handled. Click here to learn how to handle this situation.