Preparation And Research Of Photonic Crystal Particles Based On Solvent Extraction

Photonic crystals are materials that exhibit periodic changes in refractive index and are widely used in optoelectronic devices.The preparation of photonic crystal particles usually requires the solvent to be removed by evaporation or extraction,the solvent for removing the solvent by evaporation is slow,and the heating is required;the extraction method removes the solvent at a high speed and does not require heating.This article intends to use the extraction method to prepare photonic crystal particles and study the influencing factors of their morphology and assembly quality.The specific research contents and results are as follows:Firstly,the photonic crystal particles were prepared by solvent extraction at the gaswater-oil three-phase interface.The photonic crystal particles were observed and characterized by microphotography,SEM and microspectroscopy,and their formation mechanism and optical properties were analyzed.The results show that the photonic crystals begin to assemble at the three-phase boundary and then slowly develop toward the middle,and assembly the whole photonic crystal particles in the end.The entire particle showed as pie-shaped,and its upper surface of the photonic crystal particles is concave and the lower surface is flat.Its microstructure is arranged in face-centered cubic,and the degree of ordering on the edge of the upper surface is higher than in the middle;its photonic bandgap is located at 530-550 nm.Secondly,the effect of PS mass fraction,extraction rate and evaporation rate on the assembly quality of the pie-shaped photonic crystal particles was studied respectively.The results show that with the increase of the mass fraction of PS,the shape changes from a ring shape to pie shape;When the mass fraction of PS is 12%,the assembly quality is the best.With the increase of the extraction rate,the assembly quality of the lower surface becomes worse and the change of the upper surface is not obvious.With the increase of the evaporation rate,the assembly quality is improved.Finally,the photonic crystal particles were prepared by solvent extraction method in the oil phase,and the effect of PS mass fraction and extraction rate on its morphology was studied.The results show that the polyhedron-like photonic crystals can be prepared in the oil phase by solvent extraction.The sphericity of the photonic crystal particles increases with the increase of the mass fraction of PS,and the shape changes from spherical to polyhedral with the increase of the extraction rate.The specific performance is: When the volume ratio of n-butanol and n-octanol is greater than 1:1,the shape is a polyhedron-like;when the volume ratio of n-butanol and n-octanol is less than or equal to 1:1,the morphology tends to be spherical.