Silica that originated from the calcination of rice husks, which is a source of biomass silicon, was added as a reinforcing agent to waterborne polyacrylate wood coatings to improve their coating performance, and especially their mechanical properties. The morphology of the rice-husk ash, aggregation and dispersion of modified silica in the polyacrylate emulsion and the surface roughness of the coating on wood were characterized by scanning electron microscopy, transmission electron microscopy

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... nd atomic force microscopy. The film mechanical properties and performance were investigated. The rice-husk ash calcined at 650 °C exhibited a particle size of 5-20 μm. Silica modified by silane coupling agent KH-570 was dispersed in waterborne acrylate coatings with a submicron scale. For a 2 wt% modified silica loading, the surface roughness of the coating on wood was influenced slightly and the elongation at break, the tensile strength, the elastic modulus, and the pencil hardness of the polyacrylate film were 303.06%, 48.673 MPa, 6.672 MPa and 2H level, respectively. The adhesion strength was enhanced significantly to level 0 with an increase in modified silica loading. The changes of film abrasion loss and gloss for the five groups are not obvious. The silica-modified coating exhibited slightly hydrophobic properties and a better lipophilicity. This paper provides a feasible route for the value-added utilization of rice husk.