Poroelasticity of cellulose hydrogel

The poroelasticity of cellulose hydrogels was studied by a series of compression tests. The stiffness of the cellulose hydrogel was found to be independent on the crystallinity of a skeletal gel matrix, suggesting that the poroelasticity made a significant contribution to mechanical properties of the hydrogel. Indeed, typical poroelastic responses were observed when the cellulose hydrogels were subjected to the compression tests with varied compression strain rates (i.e. softness upon slow compression but stiffness upon fast compression). The fluid mechanics theory showed that sub-micrometer-scale morphological difference of the gel matrix, which was observable by scanning electron microscopy, affected the flow behavior of water inside porous structure, leading to the increased stiffness upon fast compression.