Study On The Construction And Performance Of Amorphous Structure Colors Containing Silica Microspheres

In recent years,the structural color,which is caused by the interaction between the regular microstructure of the material and light,has attracted a wide attention.Compared with traditional pigments or dyes,structural color is non-toxic,environmental protection and non-fading,so the research of structural color has become one of the research hotspots in the fields of material science.The photonic band gap in the structure color can control the light,which can be divided into photonic crystal structure color and amorphous photonic crystal structure color according to its structural characteristics.The color of photonic crystal structure is bright and angle-dependent,while that of amorphous photonic crystal structure is soft and angle-independent.The rapid,simple and controllable preparation of this light-controlled microstructure material has received more and more attention from the researchers.In this thesis,the structure color was prepared by using silica（SiO₂）microspheres and titanium carbide（TiC）nanoparticles as the main components.The effects of different experimental conditions on the type of structural color and color saturation were discussed.The main research contents are as followed:Ethyl orthosilicate（TEOS）,ammonia,water and ethanol were mixed and SiO₂microspheres were obtained by hydrolysis-polycondensation process of the simple St（?）ber method.The synthesized SiO₂ microspheres were characterized by scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,X-ray diffraction（XRD）and infrared spectroscopy（IR）.The results show that the ammonia content was a key factor to control the synthesis of submicron SiO₂ microspheres.A kind of structural color with orderly arrangement was obtained by the deposition method.Firstly,SiO₂ microspheres were uniformly dispersed with isopropanol and deposited naturally on polyethylene（PE）petri dish at room temperature.After solvent volatilization,the SiO₂ microspheres were assembled to form structural color.Furthermore,TiC nanoparticles,were added to SiO₂/isopropanol dispersion to study the effect of TiC nanoparticles and the assembly temperature on the color of the structure.The results show that SiO₂/isopropanol dispersion can form structural color at room temperature.With the increase of the size of the assembled SiO₂ microspheres,the structural color was red-shifted,and was able to exhibit as blue,green or pink.At the same time,the color saturation of the structural color decreased with the increasing sizes of SiO₂ microspheres,and increased with rising amount TiC nanoparticles.Increasing the temperature during the assembly of SiO₂/TiC/isopropanol dispersion could shorten the assembly time and still formed the structural color,however,the amorphous photonic crystal structure was formed at this time.A short-range and orderly structural color was obtained by spraying method.Firstly,SiO₂ microspheres were dispersed uniformly with ethanol,then,TiC nanoparticles were added.Then the dispersion was sprayed by a spray gun to prepare the structural color on the substrate.The effects of different amounts of TiC nanoparticles and different SiO₂microspheres on the structural color were investigated.The results show that the amorphous photonic crystal structure color could be formed by spraying SiO₂ microspheres,and the color saturation was low.After adding TiC nanoparticles,the color saturation was greatly improved.Color palettes can be prepared by adjusting the size of SiO₂ microspheres and the amount of TiC added.The structural color prepared by this method showed a stable performance and could be processed.