I'm making a poly(lactic-co-glycolic acid) film from CH2Cl2 in a flat aluminum dish. The film itself is fine, but sticks to the dish to the point of having to stretch and even warp the film.
Using a flat glass or PTFE dish might help, but I haven't readily found dishes that are truly flat (e.g. petri dishes I've gotten don't have a uniformly flat enough surface). I can't use a plastic dish that is not inert to DMSO, either. So, does anyone have a recommended casting dish or similar that they can recommend?
Aside from trying to find out the perfect casting dish or tool, is there any other suggestion for helping to readily remove the film? I had been thinking of casting a film of PVA first, and then just washing that out with water. Would that or something similar be efficacious?
What I have done before is place a flat quartz plate at the bottom of the aluminum dish and it works for some polymer if your polymer is not readily sticking to it. Obviously iyou are going to loose a lot of solution like this...
You could try to put a few drops of your solution on quartz to see if it sticks
Depending on the thickness of the film you need you could try spin casting the film on quartz or glass and that could also work.
Nicolas
My lab gets the glass-blower to make truly flat-bottom petri dishes and drop-casts in those - you get a ring around the edge but variation can get down to ±5 microns or sometimes better once you get the technique down. On a larger scale, casting tables work well and can give you consistent films to ±2 microns or even lower (essentially a heated glass sheet + a squeegie that's kept extremely level).
And I'm intrigued by the idea above - it may do the trick. I was going to say it may be possible to use release paper as a liner - many sticky-to-cast commercial membranes are cast on various substrates that are treated to release the polymer better, typically silicone-treated from what I gather, and there's a few that may be fine with DMSO. That said, if you can find a supplier willing to give samples or are willing to sell quantities less than a full roll, please let me know!
apply some paraffin oil on casting plate than wash off the film
I am having same problem with polymer film synthesized with metal oxide filler and various concentrations.The polymer itself (Hyaluronic acid ) without filler easily removes from petri dish .Trying to find a solution to this and it's making it impossible for me to proceed in characterizing the mechanical and physical properties of this film.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science