Construction of organic-inorganic hybrid coating polymer with in situ SiO2/PDMS on the surface of wood

Abstract

Abstract Wood has a large number of hydrophilic groups and pore structures, with strong moisture and water absorption abilities, and is prone to problems such as deformation, cracking, and discoloration. In order to improve this phenomenon, surface modification of wood has always been a hot topic in wood science research. To address the problem of poor water resistance of wood, the organic-inorganic hybrid superhydrophobic layer was constructed bionically on wood substrate by dipping coating method or spraying method based on the principle of lotus leaf effect, using inorganic fillers such as nano-silica/organosilicone oil and transparent polymer of water-based acrylic varnish as organic matrix. In this study, monodisperse nanometer-sized SiO2 microspheres were prepared via the Stöber method and the wood surface was modified by self-assembly of a solution. Then, the prepared modified nanoparticles SiO2/PDMS mixture solution was alternately and cyclically coated on the surface of the wood to obtain SiO2/PDMS in situ organic-inorganic hybrid modified wood samples. The results showed that the porous structure of the white wax wood surface was fully covered by SiO2/PDMS in situ organic-inorganic hybrid coating polymer after coating, forming a dense protective layer. SiO2/PDMS in situ organic-inorganic hybrid modified wood samples not only did not change the original color and texture of the white wax wood material, but also had a contact angle greater than 150° for the surfaces of 7 common droplets (deionized water, tea, cola, juice, vinegar, ink, red wine), indicating that introducing a SiO2/PDMS organic-inorganic hybrid coating to modify the wood surface can endow the wood with good superhydrophobic properties. This is mainly because the hydroxyl groups in the SiO2/PDMS in situ organic-inorganic hybrid coating deposited on the wood surface are combined with the hydroxyl groups on the wood surface, reducing the number of hydroxyl groups on the surface. In addition, the presence of long-chain fluorinated polymers also increases the hydrophobicity of the wood surface.