Usually do to poly-condensation forms water or alcohol after removal of which from your films shrinks the films due to high surface tension of the water or alcohol you can avoid this by replacing the solvent in the films by low ST liquid such as hexane. which we used to do for the preparing silica aeorgels. you can check papers  such as

http://link.springer.com/article/10.1007%2Fs10934-010-9444-7

http://www.sciencedirect.com/science/article/pii/S1293255812004025

http://www.sciencedirect.com/science/article/pii/S0032591013001228

http://www.sciencedirect.com/science/article/pii/S0272884212006748

@ V. V. Ganbavle: Thank you for your reply. In fact, we can not use other solvents in place of water. The field of application is different.

If it is so you can try supercritical drying of your films at high pressure and temperature. I think it may help.

Yes, My next target was either freeze drying or super-critical drying. Thanks...

You can dispense the required volume using a pipette tip in between two glass-cover slips separated by a spacer (made by cutting pieces of teflon sheet). Paper clips can be used to hold the spacers in place at the edges. This will make the gels perfectly flat.

use glycerol which reduce shrinking behavior

@ Dinesh Gautam: Thank you for your reply. ya good idea...Glycerol can moistens the hydrogel....but does it affects the properties of hydrogel......

Just go for freeze drying of the hydrogel.

you can try freeze drying after equilibrium swelling...I had done this and got good results..