Carbon fiber is widely used in aerospace, automobile, chemical industry, infrastructure, military, sports, energy, textile and other fields due to its unique physical and chemical properties. However, carbon fiber type of graphite structure makes the surface shows chemical inertness, low interfacial energy, interface infiltrates poor performance and high temperature oxidation resistance and the lack of high reactivity of functional groups, which makes between carbon fiber and other substrate materials cannot form effective coupling interface, the interface strength decreased, which seriously affects its mechanical properties. In addition, low chemical bonds with dye molecules are used to make it difficult to dye, resulting in too monotonous hues of carbon fiber products, which can not meet the needs of consumers.

Existing methods of the realization of the carbon fiber fabric shading: woven with about 50% of the dyed yarn, such as glass fiber, polyester, copper, aramid fiber, etc, but also on the mechanical properties of the carbon fiber fabric will drop accordingly; An apple patent, US7790637 B2, changes the color of carbon fiber fabrics by adding an additional "scrim". The university of Manchester has recently developed a new electrochromic resin that can be used for carbon fiber preloading to produce stable, reversible color changes under the action of an external electric field.

However, it is still a problem that scientists need to solve the problem of maintaining the high mechanical properties of carbon fiber fabrics. Recently, China's hubei university professor wang and professor of wuhan university of textile wei-lin xu, etc to guide the research team developed a kind of effective, easy to operate method of carbon fiber fabric shading adjustable color not only, but also has excellent washing resistance. The study was published in the international top journals the journal ACS Nano materials science (a Facile and Effective Coloration of Dye - Inert Carbon Fiber Fabrics with Tunable Colors and Excellent Laundering Durability). According to introducing, this study mainly starting from the idea of bionic structure to the attraction, the ALD (atomic layer deposition) build scale of different technology in carbon fiber/fabric surface amorphous TiO2 film, realized the coloring of carbon fiber and its fabric.

Structure color is due to the nature, there are a series of special optical scale microstructure on visible light for selective reflection, scattering, interference, diffraction, dispersion and transmission of physical function such as colorful color. Structure color has no pollution, do not fade, high saturation of brightness, the color of the rainbow effect mechanism also has the incomparable technical advantage by other dyeing technology and broad application prospects. This provides a new way of thinking about the ecological coloring of carbon fiber.

The structure of nature

Methods used to construct structural colors include sol-gel, self-assembly, holographic lithography, inkjet printing, anodic oxidation, electrophoresis deposition, electrospinning and atomic layer deposition (ALD). ALD is a special kind of chemical vapor deposition technique, due to the limit surface chemical reaction characteristics of atomic layer deposition technique excellent conformal sex, the uniformity of large area of growth, and accurate and the characteristics of the single layer film thickness control. Nanoscale controlled chemical growth and excellent conformal characteristics with service characteristics, and convenient operation, high stability, without being limited by the size and shape of the substrate material, to the composition and thickness of the atomic level control, wide applicability, no pollution to the surrounding environment.

However, since the surface of carbon fiber fabric is mainly chemical inert sp2, it is difficult to activate the ALD reaction on CFF. The study using the carbon fiber surface defects and the oxygen containing functional groups (e.g., - OH, and - -cooh) group, which can effectively start TiO2 thin film growth characteristic, first introduced TIP (four titanium isopropyl alcohol), by the activity of carbon fiber surface - OH or - COOH groups since the limit of chemical reactions in the carbon fiber surface - OCH (CH3) 2, and the introduction of H2O and - OCH (CH3) 2 reaction to form monolayer TiO2 film and exposed - OH, after each step by the nitrogen blow the rest of the material. By repeating the number of these ALD cycles, the required TiO2 film thickness can be precisely adjusted.

A TiO2 film surrounded by carbon fiber

By controlling the amorphous TiO2 thin film thickness, the study implements the preparation, the success of the three primary colors red, yellow, blue and can through the composite primary colors, namely change the thickness of carbon fiber fabric surface is TiO2 ALD, obtain other all sorts of different color. The TiO2 film has excellent washing resistance and can withstand 50 washing. This result indicates the direction of the ecostaining of carbon fiber and its fabric.