Charge Regulated Diffusion of Silica Nanoparticles into Wood for Flame Retardant Transparent Wood

The preparation of wood substrates modified by charged inorganic nanoparticles (NPs) diffusing into the internal cell wall structure is investigated for generating functional properties. The flammability problem of wood biocomposites is addressed. NPs applied from colloidal sols carry charge to stabilize them against aggregation. The influence of charge on particle diffusion and adsorption should play a role for their spatial distribution and localization in the wood substrate biocomposite. It is hypothesized that improved dispersion, infiltration, and stability of NPs into the wood structure can be achieved by charge control diffusion, also restricting NP agglomeration and limiting distribution to the wood cell wall. Cationic and anionic silica NPs of approximate to 30 nm are therefore allowed to diffuse into bleached wood. The influence of charge on distribution in wood is investigated as a function of initial sol concentration. Transparent wood is fabricated by in situ polymerization of a thiol-ene in the wood pore space. These biocomposites demonstrate excellent flame retardancy with self-extinguishing characteristics. The approach has potential for commercial fabrication of flame retardant transparent composites for glazing and other building applications.

Automated summary

This study investigates the preparation of wood substrates modified by charged inorganic nanoparticles for generating functional properties and addressing the flammability problem of wood biocomposites. The influence of charge on the distribution of nanoparticles in wood is explored, and it is hypothesized that charge control diffusion can improve dispersion, infiltration, and stability of nanoparticles in wood structure while limiting agglomeration and distribution.