The membranes properties prepared from water/formic acid (FA)/ polyamide 66 (PA66) and water/hydrochloric acid (HCl)/polyamide 66 (PA 66) systems has been studied. The different solvents interact distinctly with the polymer. affecting the membrane morphology. The asymmetric structure of the membranes showed a dense top layer and a porous sublayer. https://pyrodresoners.shop/product-category/external-module/