Color Carbon Fiber Based On Bionic Structural Color And Its Discoloration Response

In the 1940 s,with the development of the aerospace industry,the definition of composite materials was proposed.And a large number of high-performance composite materials were produced in the following decades.Among them,the development of carbon fiber composite materials is particularly rapid.However,by the beginning of the 21 st century,the demand for carbon fiber composite materials has gradually changed from initial mechanical properties and service life to functional and intelligent with the continuous development of society.Therefore,the preparation of functionalized carbon fiber has great significance to the intelligent development of carbon fiber.The optical properties of carbon fiber are the research hotspots of functionalized carbon fiber in recent years.In this paper,the functionalized carbon fiber is studied from the color of carbon fiber.The color in nature are mainly divided into chemical color and structural color.The chemical color is generated due to the absorption of certain wavelengths of light by the electronic transition in the special chemical bond of the substance molecule,such as dyes,paints,etc.The structural color is produced by the interaction of light and the periodic microstructure on the surface of the organism.Compared with chemical color,structural color have the advantages of high color saturation,no change in structure,no fading,and environmental protection.Graphene oxide(GO)as a two-dimensional lamellar material,a fish-scale lamellar stacking structure can be formed when a large amount of GO is stacked together in an orderly manner.In this way,GO can be used as the base material to produce the structural color formed by the interference of the multilayer film.In this paper,ultrasonic and centrifugal methods are used to make GO form a nematic liquid crystal phase in water,which makes the particle size distribution of the GO sheet uniform and within the visible wavelength range.After selecting the appropriate concentration of GO water dispersion,GO is deposited on the carbon fiber by vacuum filtration.The ordered accumulation of GO layer on carbon fiber causes a series of refraction and interference of incident light to form structure color.At the same time,it was found that the prepared color carbon fiber had a response to the solvent vapor.The color carbon fiber quickly change color when exposed to solvent vapors.When the solvent vapor evaporates,the color carbon fiber will change back to its original color.These behaviors have good cycle reversibility,which makes the application of color carbon fiber in the field of intelligent materials possible.When magnesium sulfate heptahydrate is placed under the color carbon fiber and heated,the color change of color carbon fiber to temperature can be realized.When the GO layer structure on the surface of the color carbon fiber is pressed,the color of the color carbon fiber will change.GO will be reduced at high temperature,so color carbon fiber will show irreversible fading behavior at high temperature.Therefore,the color carbon fiber has the function of monitoring the solvent,temperature and strain.In the nature,some organisms have special white structural color.Different from the colorful structure color,the white structure color is formed by multiple scattering and reflection of light in disordered porous media.We prepared porous polyethersulfone(PES)bead matrix on the surface of carbon fiber,and the PFS matrix showed a high whiteness.It was found that the white color of the PES matrix is caused by its internal porous structure.Because the PES matrix has a porous structure,the heat spreads slowly in the PES matrix causing a large amount of heat to be lost when exposed to light radiation.The PES matrix plays a role of heat insulation.At the same time,the white carbon fiber can reflect more light radiation,causing the substrate to heat up more slowly.the thermal diffusion coefficient of white carbon fiber is only 1/3 of ordinary carbon fiber.It has good protection for carbon fiber products and carbon fiber composite materials that need to be used at high temperature.