Figure 1
From: Hierarchical Porous Chitosan Sponges as Robust and Recyclable Adsorbents for Anionic Dye Adsorption
(a) Scheme of the synthesis process of chitosan foams and chitosan sponges. The product obtained after lyophilization is defined as chitosan foam and the washed chitosan foam saturated with water is defined as chitosan sponge. (b) Side-view scheme of the formation mechanism of the freeze-casting process. When the uniformly dispersed chitosan solution (left scheme) is frozen, the chitosan chains gather on the surface of the ice crystals and align along the growth direction of the ice (middle scheme). After the freeze-drying process, as a result, a chitosan foam with a continuous and uniform cellular network is formed (right scheme).
