| Textile coloration is dominantly achieved by utilizing chemical colorants, dyes and pigments.Different from the traditional coloration related to the absorption of light, structural coloration without chemical colorant is involved in the elementary optical processes, such as reflectance,scattering, interference, diffraction, and so on. It is generally recognized that structural coloration is the most common way by utilizing the thin film interference effect from the interaction of light with thin films or coatings. In this thesis, the large area films with uniform color through interference effects were prepared from the charged inorganic nanoparticles and polyelectrolyte using electrostatic self-assemble technology. Considering the surface chemical properties of textile fiber, the PET, glass and PP rigid substrates were selected to test the effects for fabricating thin films with structural colors. Various composite films of Si O2/PEI, Zn O/PSS and Si O2/Zn O were fabricated on different substrates. The conditions for preparing films with uniform structural colors were optimized and the optical properties of the films were analyzed with various size of nanoparticles, increasing thickness and various viewing angles. The surface morphology and microstructure of the prepared films on substrates were characterized and the coloration mechanism was clarified. And it was verified that the film self-assembly process was driven by the electrostatic force. The application of Si O2/PEI film was proved to be feasible on the surface of textile fiber. It was believed that this study could offer some valuable experimental and theoretical guidance for expanding application of structural coloration and developing textile eco-coloration technology. The major contents and results are as follows:(1) The monodispersed Si O2 colloidal particles with various sizes were prepared by St?ber method and Si O2/PEI films were prepared by electrostatic self-assembly on three substrates of glass, PET and PP. The influence of three different substrates for film preparation were examined,and the results indicated that the Si O2 particles uniformly dispersed on substrate surface with the higher electronegativity, the higher hydrophilicity, and the lower roughness. The uniform Si O2 distribution leads to the uniform structural color. Fabricated in the optimized conditions, such as the suitable lifting velocity and the appropriate concentration of PEI and Si O2 colloids, the films would demonstrate better uniform and reproducible structural colors.(2) The Si O2/PEI films was fabricated on PET and glass substrate respectively. Its structural colors changes with various particle sizes and increasing cycles. And the corresponding wavelength of the structural colors has a red shift. Under various viewing angle, the film has different lightness and hue. These optical phenomenon were strongly conformed with thin film interference effect of single layer. The surface morphology and microstructure of the film alsoindicated the Si O2 particles and PEI formed a homogeneous coating on substrate. The electrostatic driving force was conformed for the self-assemble process. Compared with short range van der Waals force, the long-range electrostatic attraction between the charged polymers and inorganic nanoparticles plays a chief role, which leads to spontaneous assembly and the longitudinal growth of the film. But the electrostatic repulsion between the charged nanoparticles forbid the endless increasing of the film. It was suggested that the coexistence, confrontation and balance system of electrostatic attraction and repulsion drives the nanoparticles in film to form cross layer structures. Based on these, the model of electrostatic self-assembly process was put forward.(3) Zn O colloids were synthesized by sol-gel method involved two steps and Zn O/PSS films were fabricated on PET substrates. Because the effective refractive index is higher than that of its adjacent medium, the Zn O/PSS layer has a higher brightness. Varied with changes the sizes and increasing cycles, the structural colors was prone to originated from single layer thin film interference. The surface morphology also indicated the Zn O particles and PSS formed a homogeneous coating on substrate. The structural colors was originated from the optical single layer thin film interference effect.(4) Because the Si O2/PEI and Zn O/PSS optical monolayer films all have low reflectance, only two ahead rays was considered in the multiple beam interference. They have different constructive interference conditions because of low reflective index of Si O2/PEI film and high reflective index of Zn O/PSS film. And the value of reflectance is exactly opposite when the thin film optical thickness nd=λ0/4. Based on the investigation of the monolayer films, the more complicated Si O2/Zn O multilayer thin films were fabricated and its colors were studied. It was showed that the Si O2/Zn O multilayer film had lower brightness, the lightness and saturation with changed with increasing assembly cycles, which probably related to the heterogeneous transitional layer in the refractive index of gradual change from n1 to n2.(5)The tentative application of the obtained Si O2/PEI film with structural colors was explored on flexible polyester fabric surface, and it was proved to be feasible.The influence of various factors for structural colors was examined. The results indicated that the optical phenomenon of Si O2/PEI films on the surface of fabrics is similar with that on PET substrates. But the structural colors on fabrics has lower brightness. It was strongly suggested that the uneven structure and the rough surface of the flexible polyester textile were responsible for weakening the interference effect, the scattering and diffuse reflecting, etc. |
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