Bleaching is a common modification method widely used in the industrialization of wood dyeing. Bleaching can regulate the color of the wood, and it also has great effects on the subsequent wood dyeing properties. In this work, three woods, Ayous, Linden, and Poplar, were processed by using the NaOH/H₂O₂/Na₂SiO₃ bleach pretreatment method. Then, the pretreated wood and untreated wood were stained separately by means of water bath dyeing with three dyestuffs: blue anthraquinone and red and yellow double-azo dyestuffs. The study mainly focused on the effect of the bleach pretreatment on the color control and dyeing properties of the wood by analyzing the color difference, staining rate, and final dyeing rate of the dyed wood. The results were as follows: For the color difference, the L* and h* values showed increasing tends, while the a*, b*, and c* values showed decreasing trends. For the staining rate, Ayous reached an equilibrium staining rate at 3~4 h, but for the others, this was not obvious. For the dyeing rate, red and blue Linden veneers and blue Ayous veneers were similar to the unbleached ones, while the final dyeing rate of the other veneers was less than that of the original wood, and the staining rate of the Ayous red and yellow veneer, Linden yellow veneer, and Poplar veneer was less than that of the original wood. The final dyeing rate of the Ayous red and yellow veneers, Linden yellow veneer, and Poplar red, yellow and blue veneers decreased by 4.54%, 2.91%, 5.45%, 10.75%, 2.66%, and 9.55%, respectively. In general, the bleach pretreatment made the staining color of the material surface uniform. The dyeing rate increased due to the increase of the veneers’ permeability. Thus, the veneers quickly reached the equilibrium staining rate, but the equilibrium staining rate of some test pieces decreased. This work provides scientific support for the dyeing process.

Polystyrene (PSt) microspheres were used to construct rainbow-like, seven-colored structural color coatings on wood surfaces by analyzing how the amount of emulsifier SDBS and emulsion polymerization temperature affected the particle size and monodispersity of the microspheres. The influence of both the amount of self-assembled emulsion coating used and the temperature on the reflected spectrum and the color of the coatings was investigated. It was found that the most monodisperse PSt microspheres were obtained when using 175 mg SDBS and a reaction temperature of 70 °C. By adjusting these two factors, we regulated the particle size of the PSt microspheres. When PSt microspheres were self-assembled on a wood surface to form a structural color coating, the best optical effect was obtained with 40.8 × 10⁻³ mL/cm² emulsion amount and 50 °C ambient temperature. Finally, by changing the SDBS amount and reaction temperature, microspheres with different particle sizes and good monodispersity were prepared. The structural color was used to form patterned decorations on the wood surface, providing a technical basis for forming other structural color coatings on wood surfaces.

Colloidal microspheres could be used as raw materials to construct the photonic crystal modification layers on wood surfaces, and the wood would produce gorgeous structural color effect. The diameter, monodispersity and self-assembly of colloidal microspheres directly affect the well-structure order of photonic crystals. Therefore, poly(styrene-acrylic acid) (P(St-AA)) shell-core microspheres were prepared by emulsion polymerization. The effects of the reaction time, amount of initiator and emulsifier and reaction temperature on the particle size and dispersity of colloidal microspheres during polymerization were analyzed by single-factor experiments. The P(St-AA) colloidal microspheres self-assembled on wood surfaces and formed photonic crystals with structural color through thermally-assisted gravity deposition. The effects of the amount of emulsion coating per unit surface area and ambient temperature on the optical properties of the photonic crystals were investigated. It was found that the particle size of the synthesized microspheres increased with the increase of initiator amount and reaction temperature and the decrease of emulsifier; however, the effect of reaction time on microspheres was less regular. The best optical properties of the photonic crystals on wood surfaces were obtained using 0.408 μL/mm² emulsion coating at a temperature of 50 °C. The photonic crystals were composed of both ordered and disordered layers.