Preparation And Application Of Photonic-crystals Pigments

There are a variety of vivid and fascinating colors in the nature,such as beetle shells and butterfly wings.With the further study of photonic materials,it was found that these beautiful colors that exist in nature are not produced by dyes or pigments.They generated from the interaction of natural light and micro-nano photonic structures.The colors based on these physical phenomenon are defined as structural colors.Natural light could be photodecomposited after a series of interference,diffraction,or scattering.Partial light will pass through or be absorbed by the photonic structure,and the rest of the light will reflected forming the observed structural colors.At present,using dyes and pigments are still the mainstream coloring methods.However,the large number of dyes and additives has increased the difficulty of environmental management.Structural color is the product of nature's wisdom.It does not rely on chemical dyes or auxiliaries,does not fade,and is pollution-free,which much better matchs the current theme of green environmental.In this thesis polystyrene(PS)microspheres are used as the basic unit and carbon blacks(CB)nano particles are used as the co-assembly material to form a crystalline photonic film.The highly flat crystalline photonic films are then broken into photonic pigments.The main contents include:(1)PS colloidal microspheres with various sizes are prepared using an improved emulsion polymerization method,and the PS microspheres are self-assembled into a crystalline photonic films by a dual template preparation method.Micro cracks formed in the microsphere self-assembly process are used to decompose the photonic film to obtain micron-sized photonic pigments.Photonic pigments have a stable structure and a bright color with unique pearlescent effect.The microscopic morphology and optical properties of photonic pigments are characterized in detail,and the optical properties are explained by a new proposed formula.(2)Structural color fibers are fabricated through capillaries.The photonic pigments are added into the precursor polydimethylsiloxane(PDMS)and mixed uniformly.After adding a thermal curing agent,they are injected into a polytetrafluoroethylene capillary for curing and molding.After curing,the PDMS fiber is transparent,the color of the photonic pigments embedded in the fiber is obvious,and the structure is stable.The optical properties and internal microstructure of structural color fibers are characterized.(3)Pearlescent patterns are prepared on a cotton fabric by using a mask.Spread the photonic pigments on the surface of the cotton fabric covered by the mask to form the designated patterns.The pearlescent patterns have stable bright colors and angular dependence.The stable color,angular dependence and pearlescent effect of the pearlescent patterns are characterized in detail.The application of photonic pigments in transparent nail polish.Photonic pigments have bright colors,shiny luster,metallic flashing effect and profound three-dimensional space texture,which has certain application potential in the field of ink and makeup.