Microstructure, hydrophobicity and thermal stability of wood treated by silica/montmorillonite nanoparticle-stabilized Pickering emulsion (I)

Silica/montmorillonite nanoparticles (silica/MMT-NPs) were synthesized by sol–gel method for stabilizing paraffin oil Pickering emulsion (oil-in-water) which was used for wood treatment. The self-condensation during silica/MMT-NPs preparation resulted in intercalation rather than delamination for MMT, leading to increased droplet size of Pickering. The droplet size increased with the increasing concentration of silica/MMT-NPs owing to the aggregation of nanoparticles. After Pickering treatment, a rough surface could form via silica/MMT-NPs deposition in cell lumens, which was covered by paraffin to attain hydrophobicity. Moreover, paraffin penetration and pore-filling of hybrids in cell walls were beneficial for decreasing water absorption, and nanoparticles improved the thermal stability. These findings indicated a synergistically effect provided for improving properties of treated woods via one-step method.