use a  wire loop

Dear Dr.Jianjing Xu

I was used it but polymeric membrane make arc and lid to rupture of membrane and structure and surface of  membrane is not smooth and flat.

Thanks for your answer.

Hi. It depends on the size of the membrane in part.  Your membrane will have to have a support so that you can test the permeability .  place the support under the water before spreading the membrane then lift the support evenly from one side, so the membrane is supported while being removed.  The best supports are the smooth spun bonded materials, because of their smoothness and uniform porosity.

Good luck

Hi

I dont know which polymers you are using. If the polymers are insoluble in ethanol then you can put some ethanol on the surface of thin membrane. It will slightly coagulate the formed membrane and might help in detaching the membrane.

I hope this trick might help you.

Regards,

Parimal