Cellulose nanofiber nanocomposites with aligned silver nanoparticles

Celluloses have attracted much attention as sustainable and abundant materials. Herein, we focus on nanocomposites based on the oxidation-treated nano-sized fibrillated celluloses, namely TOCNs. The silver nanoparticles (AgNPs) were prepared in TOCN aqueous dispersion. Generally, the AgNPs are quickly agglomerated after preparation. For the inhibition of the agglomeration of AgNPs, it is required that AgNPs were prepared under the chelation of TOCN, followed by reduction therein. Therefore, AgNPs possessed the nano-scaled radii and aligned along the TOCN from the atomic force microscopic measurements. The thermal stabilities and mechanical properties were increased. The anisotropic thermal conductivities originated from the orientation of TOCN in nanocomposites were observed. The loading of the large amounts of AgNP fillers led to the drastic increase of the thermal and electrical conductivities. The conductive paths of heat and electron were formed by the contact of AgNP with each other. We functionalized the TOCN papers through the loading of AgNPs and the obtained nanocomposites sheets served as conductors.