Mechanical effect of acetic acid lignin adsorption on honeycomb-patterned cellulosic films

We have already fabricated honeycomb-patterned cellulosic films with cellulose I and II polymorphisms as a basal framework in order to create an artificial woody cell wall. The adsorption of an isolated lignin, acetic acid lignin (AL), was attempted onto the honeycomb films not only to develop materials further mimicking the cell wall but also to elucidate the mechanical effect of isolated lignin on the tensile strength of the cellulosic architecture. The tensile strengths of honeycomb-patterned cellulosic films were improved by the AL adsorption. Although the cellulosic films without lignin weakened under high moisture content conditions as compared with those under the low content conditions, the lignin-adsorbed cellulosic film maintained significant tensile strength even under the high content conditions. This result suggests that lignin contributes to reinforce the mechanical strength of cellulose framework, in particular high moisture conditions.