Preparation And Properties Of Polysaccharide-based Gel Photonic Crystal Films

Photonic crystal is a new type of optical structure material,the photonic band gap can be modulated.If the photonic band gap is in the visible range,the color of photonic crystal is visible to the naked eye.The photonic crystal is embedded in the stimulated response gel.When the external stimulating substance interacts with the gel,the water content and volume change inside the gel change the structure color of the photonic crystal,so the combination of the photonic crystal and the gel is widely used in the field of sensors.In this paper,two kinds of multi-responsive gel photonic crystal films were prepared by using the natural polymers of saccharide,and the preparation of the responsive gel photonic crystal films was further extended.Monodisperse,uniform particle size and high charge polystyrene microspheres were prepared by non-emulsion polymerization method.The effects of the amount of monomer styrene and the amount of acrylic acid on the size of microspheres and the amount of microspheres charged were discussed.With the increase of the amount of monomer styrene,the particle size of the microspheres increased.With the increase of the amount of monomer acrylic acid,the particle size of the microspheres decreased first and then increased,and the charge rate increased and then decreased.A template for the preparation of three dimensional photonic crystals was prepared by selecting polystyrene microspheres with a diameter of about 220 nm.The effects of temperature and polystyrene microsphere monodisperse concentration on the template were discussed.It is found that the photonic crystal film with uniform thickness and uniform structure can be found at 40 ?;With the increase of the polystyrene microsphere monodisperse concentration,the trend of the reflected light intensity and the degree of cracking have increased;It is found that the photonic crystal mode prepared by polystyrene microsphere dispersion with mass fraction of 0.25% has stronger intensity and no crackWe selected carboxymethyl cellulose and carboxylated chitosan respectively to fill the photonic crystal template,prepare carboxymethyl cellulose gel photonic crystal film and carboxylated chitosan gel photonic crystal film.The effects of the concentration of the filler,the amount of NaOH solution,the amount of the crosslinking agent on the integrity and swelling degree of the gel photonic crystal film were discussed,The optimum preparation conditions for the carboxymethylcellulose gel photonic crystal film were 1 g of 5% by weight of carboxymethylcellulose,10 ?L of a 25% NaOH solution and 5 ?L of a vinyl sulfone crosslinking agent.The optimum conditions for the preparation of the carboxylated chitosan gel photonic crystal film are 1 g of carboxylated chitosan with a mass fraction of 10%,10 ?L of a 15% NaOH solution and 10 ?L of a 50% volume fraction of vinyl sulfone ethanol solution.According to the properties of the two kinds of gel photonic crystal films,the carboxymethyl cellulose gel photonic crystal film was applied to response study of the solution pH,ethanol concentration and concentration of Pb2+,Cd2+,Hg2+.The carboxylated chitosan gel photonic crystal film was applied to response study the solution pH and the concentration of Pb2+,Cd2+,Hg2+.The results show that the two kinds of gel photonic crystal films have obvious response to the above-mentioned environmental stimuli.With the change of environmental stimulus,the spectral of gel photonic crystal film is shifted,When the environmental stimulus changes greatly,the change of the structure of the gel photonic crystal film can be seen by the naked eye.