Preparation And Application Of Photonic Crystal Hydrogel Materials Based On Microfluidic Technology

Colloidal photonic crystals are periodic ordered structure materials with different dielectric constants arranged regularly in space,with photonic band gap and excellent optical diffraction characteristics,many applications have arisen in the control of spontaneous emission and the manufacture of novel optoelectronic devices.In recent years,polymer-based composite materials have attracted widespread attention on account of their connatural environmental performance and degradability.Among them,polymer hydrogels are a very interesting class of "soft substances",which can absorb a large amount of water due to their special three-dimensional network structure.Therefore,the functional integration between photonic crystals and functional hydrogels endowed give the functional hydrogel colorful structural colors to effectively enhance its application value.Based on this,this dissertation takes monodisperse nanoparticles as the building unit,which aims to realize the morphology control and functional integration of photonic crystal hydrogels,and at the same time,with the help of process control of microfluidic technology,the preparation and application of advanced materials for photonic crystal hydrogels provide a simple and practical way.The basic research contents are as follows:1.Firstly,the microfluidic technology was developed to construct monodisperse polymer microspheres.By researching the relationship between the microsphere particle size,morphology and fluid channel,the flow rate of each component,to explore the technology for preparing monodisperse polymer microspheres with stable structure.Using methyl silicone oil as the continuous phase and an aqueous solution containing 1-vinylimidazole and hydroxyethyl acrylate hydrogel monomer and initiator as the dispersed phase,a droplet template containing hydrogel monomer was prepared using microfluidic technology,and then the monodisperse poly(VI-co-HEA)hydrogel microspheres were prepared by cross-linking and curing.The constitution and morphology of hydrogel microspheres were analyzed in virtue of FTIR,SEM,etc.The ability of poly(VI-co-HEA)hydrogel microspheres to desorb heavy metal ions(Cu2+,Ni2+,Zn2+)was inspected.The solution absorption capacity of poly(VI-co-HEA)hydrogel microspheres under different pH conditions and the relationship between metal ion adsorption capacity and contact time and metal ion concentration were investigated.The results manifested that poly(VI-co-HEA)hydrogel microspheres can achieve excellent results for desorption of heavy metal ions such as Cu2+,Ni2+,Zn2+in wastewater.2.Secondly,Fe3O4@SiO2 colloidal nanoparticles were prepared by high-temperature hydrolysis method combined with Stober method for the assembly of one-dimensional photonic crystals.Based on the excellent optical properties of photonic crystals,the self-healing photonic crystals hydrogel materials with stable structure colors were constructed by embedding it in the hydrogel matrix with self-healing ability.The hydrogel material using O-carboxymethyl chitosan(O-CMC)modified biodegradable material poly(1-vinyl-2-pyrrolidone-co-acrylamide)as the matrix has the characteristics of self-healing,the one-dimensional Fe3O4@SiO2 photonic crystals structure loaded inside the hydrogel can display bright structural colors.In addition,the O-carboxymethyl chitosan contained in the matrix can provide a large number of carboxyl,amino,and hydroxyl functional groups,which can form abundant intermolecular hydrogen bonds,thereby providing a strong self-healing ability for structural color hydrogels.This work may be used as a simple method to manufacture colloidal photonic crystal materials with a longer functional life and thus expand their practical applications.3.Finally,the basic construction unit of colloid photonic crystal materials as a starting point,and the droplet template was generated by means of microfluidic chip.At room temperature,the water in the droplet gradually volatilizes,and the colloid particles in it are closely packed and self-assembled to form a face-centered cubic structure and indicate the structural colors.After ultraviolet irradiation,the hydrogel monomers in the droplet are polymerized to form photonic crystal microspheres.In addition,composite microspheres with photonic band gap and fluorescence function were successfully prepared by loading CdTe nanocrystalline with the swelling property of hydrogel.And the application of composite photonic crystals microspheres in environmental humidity monitoring was studied.