Whether or not the film can be detached from the substrate depends on the type of the polymer (interaction between the two). Try to immerse the coated glass in a water bath right after coating; you can slightly peel a tiny edge for initiation. I am not really working on integrally asymmetric membrane, but I guess you usually need this process for phase inversion if the water is your non-solvent. If it doesn't work, try to use an acrylic glass slide instead. It worked for me to make a cellulose freestanding film.
Try floating overnight in sodium hydroxide solution (10%) it will separated completely
For PVA "silicone cookie sheet" is the best substrate! So, put a flat silicone cookie sheet on the glass surface and go ahead.
Sometimes an AC magnetic field will delaminate dissimilar materials. Also a static electric charge applied to the glass may help in separation.
Tiara Puspasari , first thanks for your answer , yes usually i did the same for phase inversion process but this if the water wasn't the solvent and that's the difference here , water is my solvent for PVA
Raheeq Naser, thanks for the answer i would try it but as i am not expert in polymer , do you think that won't affect on the PVA properties ,
Dear Asma
my experience in PVA as follows:
45 gof PVA / L distilled water gives good films
peter dishes 10.5 cm with 60 ml slution is enough
you must use dry furnace fixed at 35 or 40 degree for three/four days
after that you must have hard gloves (cotton or other) in you hand to avoid its broken in your hand
use some sharp tools like steel pen to crack the films on the edges of the peter dishes
and try to remove the film from the edges slowly and it can picked up with you
this some details you can apply easilly
Ibrahim
Dear Yahia ,
Thanks for your intention and answer , actually i used a NaOH +NaSO4 solution as coagulation solution and its easily to peel it off after 24 hr soaking in it
But may i ask you , what was the thickness of the membrane that you prepared with that petridish ???
Thanks
Regards
Asmaa
You could also consider soaking the glass substrate with its supported poly(vinyl alcohol) (PVA) membrane in cooled diethyl ether (possibly mixed with 'dry ice'), to facilitate detachment. Some care would be needed, however, since the membrane, deprived of flexibility, can easily crack.
I am facing same problem with simple chitosan based films. Any suggestion (except neutralization)?
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