Super-hydrophilic/oleophobic chitosan/acrylamide hydrogel: an efficient water/oil separation filter

Oil spills are one of the most serious problems which have a negative effect on our environment especially on the marine ecosystem. Thus, water/oil separation is considered as an important process to eliminate the oily pollutants. In the current study, a super-hydrophilic and super-oleophobic filter was prepared by in situ synthesis of chitosan/acrylamide hydrogel on the cotton fabric as a substrate. Different concentrations of chitosan and acrylamide monomers, cross-linking agent (MBA), and thermal initiator (APS) were tested by the Design Expert 7.0.0 Central Composite (CCD) software and the water absorption capacity of hydrogels were evaluated by a tea-bag method. The optimum concentration of MBA and APS was measured 0.03 g and 0.1 g, respectively. The optimal hydrogel-based filter was characterized by FTIR and SEM tests. The results confirm the successful synthesis of chitosan/acrylamide hydrogel with a porous structure on the cotton fabric. In addition, according to the results of the swelling study, the optimal synthesized hydrogel has high water retention capacity with a great stability in the seawater-simulated medium. Moreover, contact angle measurement and water/oil separation test demonstrate the super-hydrophilic/oleophobic behavior and high efficiency and durability of filter for water/oil separation.