Functional Wood–Foam Composites for Controlled Uptake and Release

High Resolution Image Download MS PowerPoint Slide Wood–foam hierarchical composites were produced via the shear-forced infiltration of shear-thinning nanocellulose-based foams or gels into the tracheids of Picea abies . Shear processing viscoelastic and shear-thinning aqueous foams composed of cellulose nanocrystals, methylcellulose, and tannic acid (total solids content: 2 wt %) resulted in foam-filled wood composites containing 15–20 wt % foam, with open foam structures and compression strengths similar to those of unmodified P. abies . An amino-functionalized nanocellulose-containing foam confined in wood reversibly adsorbed CO 2, retaining 15% of its theoretical uptake capacity over 50 cycles in the thermogravimetric analyzer, and a citronellol-loaded foam released this mosquito-repellent compound over four days, as evaluated using solid-phase microextraction. Shear-forced infiltration of functional foams into wood is an operationally simple route to hierarchically porous composites based on renewable materials.