Nano-Fe3O4/bamboo bundles/phenolic resin oriented recombination ternary composite with enhanced multiple functions

High-performance bamboo-/wood-based structural or building materials have attracted more and more attention as a kind of renewable carbon cycle materials. However, biomass materials are prone to mildew, poor surface hydrophobicity and bad dimensional stability when used outdoors, which seriously restricts their applications. In this work, nano-Fe3O4/bamboo bundles/phenolic resin oriented recombination ternary composite boards are successfully fabricated by directional recombination and hot-pressing of nano-Fe3O4 decorated bamboo bundles. Through the combination of iron/alkali liquid step-by-step impregnation and nanocrystalline in-situ crystallization, nano-Fe3O4 particles are pre-modified on bamboo bundle surface with characteristics of directional arrangement along the fiber direction. The obtained samples which are named as T1, T2 and T3 with increasing nano-Fe3O4 loading content, exhibit enhanced hydrophobicity along with varied physico-mechanical properties. Among them, T2 possesses the best compressive properties, dimensional stability, and mildew resistance, being attributed to the role from nano-Fe3O4 in bridging and enhancing the interactions between bamboo bundles and phenolic resin through ion-dipole interaction between iron atoms and electron-rich oxygen atoms. Furthermore, on the basis of maintaining the unique pore-line staggered structural characteristics of bamboo, the construction of micro continuous equivalent circuit network of the ternary composites is realized, endowing their efficient electromagnetic dissipation capacity. Our work provides systematic experimental and theoretical support for the application of high-performance outdoor recombinant bamboo board in specific scenes.