Preparation, characterization and applicability of cellulose acetate membranes modified by aliphatic hyperbranched polyester

Cellulose acetate (CA) membranes have several advantages over other membranes due to their moderate flux, high salt rejection properties, renewable source of raw material, etc [1].Many studies have been done to improve the thermal or ultrafiltration properties of the CA membranes by the additionof organic or inorganic substances [2]. Performance of CA can be improved by mixing it with appropriate additives to fulfill new requirements andassociated membrane properties. The phase separation (inversion) method is one of the most popular methods used to produce porous polymeric membranes. also recently, dendritic polymers became a novel type of membrane material [3]. Because of their highly branched structure, these polymers canhardly crystallize, and possess larger free volume than linear polymer with similar structure of unit. Other studies show The increasing content of hyperbranched polymer in the casting solution led to an increase in surface pore size and porosity of the membranes, which in return increased the pure water fluxof the blend membranes[4]. These reports were mainly focused on the gas separation and ultrafiltration.