Wood‐inspired polyacrylonitrile foam with hierarchically aligned porous structure for application in water purification

The main purpose of this study is to verify the excellent absorption efficiency of polyacrylonitrile (PAN) foam which has a hierarchically aligned porous structure similar to wood for water purification. Ice template and freeze drying method was employed to prepare the PAN foam, and the performance of the prepared sample was characterized by advanced technology. Experimental data revealed that the micromorphology, absorption efficiency, and mechanical properties were tunable by controlling the polymer concentration in solution. The PAN foam prepared at 7 wt% not only had excellent absorption efficiency, but also had great water flux. The highest absorption efficiency of the PAN foam prepared at 7 wt% for the model dye, methylene blue, reached 97.83%. Therefore, a new strategy for water purification by filtration using a scaffold with a hierarchically aligned porous structure is possible.