Construction of bionic structural color coating on wood surface based on polystyrene microspheres

HU Jing;LIU Yi;WU Zhihui;PANG Xiaoren;College of Furnishings and Industrial Design, Nanjing Forestry University;Zhejiang Shenghua Yunfeng New Material Co.Ltd.;

structural color coating;;wood structural color;;polystyrene;;microsphere;;biomimetic;;photonic crystal

In order to explore the color decoration technology of wood surface, the influence of reaction time and the amount of initiator ammonium persulfate(APS) on the microspheres was investigated by the emulsion polymerization method using styrene(St) as a monomer. Polystyrene(PSt) colloidal microspheres with good monodispersity and uniform structure were synthesized. The microspheres were self-assembled on the wood surface by the thermally assisted gravity deposition to form a photonic crystal coating with a bionic structural color. Through the characterization and analysis of PSt colloidal microspheres in the condition of neutralization and drying, it was found that the diameter of the hydrated particles in the emulsion was larger than that in the dry state. Through the characterization analysis, it was concluded that, when the polymerization time was 10 h and the APS dosage was 150 mg, the obtained PSt colloid microspheres had the best monodispersity. At the same time, it was found that, when the APS content was too low, it could not achieve a good initiation effect, and the monodispersity of the synthesized microspheres was poor. By analyzing the microstructure of the structural color coating on the wood surface, it was found that the self-assembly PSt colloidal microspheres with good monodispersity on the wood surface could form a long-range ordered photonic crystal structure, showing a bright purple color, which corresponded to the position of the reflection spectrum peak of the coating. When the particle size of the colloidal microspheres increased, the reflection peak of the structural color coating shifted to red with a larger wavelength. The poor monodispersity of colloidal microspheres and the steric hindrance in the process of assembly would make the microstructure of the coating to appear defects such as point, crack and dislocation, weakened the band gap characteristics of photonic crystals, and made the structural color of wood surface coating poor.