Influence of Cell Characteristics on the Construction of Structural Color Layers on Wood Surfaces

Abstract

When utilizing microspheres to construct structural color layers on wood surfaces, the cellular structure of wood can influence the self-assembly of microspheres and the resulting structural color layers. To investigate this influence, seven types of wood were selected in this study, and structural color layers were constructed on their surfaces. A comparative analysis was conducted on the color production and macro and micro morphologies of the structural color layers on different wood surfaces, along with an examination of the types and causes of surface defects. The study found that when a microsphere-containing emulsion was applied to a wood surface, the emulsion tended to flow along the vessels of hardwood and the tracheids of softwood. Overflow or seepage of the emulsion could lead to a reduction in the number of microspheres per unit area, resulting in uneven thickness and uneven color generation of the structural color layers. Although the structural color layers on different wood exhibited the same color, there were variations in their tones, appearance, and morphology. Defects such as minor bumps and pits were present on the structural color layers. Bump defects might originate from microsphere encapsulation of fiber bundles or the displacement of air within vessel lumens by emulsion, while pits were mainly caused by the inflow of emulsion into the vessel lumens. This study clarified the influence of wood surface cells, particularly vessels and tracheids, on the construction and color production of structural color layers, providing support for the controllable modification of wood surfaces using structural colors.