Study On Color Fastness And Hydrophobicity Of Polydopamine Structural Colored Cotton Fabrics

At present,chemical printing and dyeing is still one of the main coloring methods in the textile field,because chemical printing and dyeing requires a large amount of water and dyeing,the emission of chemical dyeing agents has a serious impact on the environment,and its dyed textiles are also easy to fade.Textile structured colours are an important alternative to the highly polluting colouring of traditional printing and dyeing.However,structural colours still have problems such as poor colour fastness and easy colour loss due to wetting,which limit the development of structural colours in the textile field.To solve these problems,this paper uses polydopamine（PDA）films with melanin-like light-absorbing properties to construct bright structural colour coatings on the surface of white cotton fabrics.The colour fastness of the structured coloured cotton fabric is enhanced by the addition of binders to introduce hydrogen bonds and the hydrophobic modification of the PDA structured coloured fabric is used to solve the problem of easy wetting and colour loss of the structured coloured fabric.The specific studies are as follows.（1）Through the self-polymerization reaction of dopamine（DA）,a polydopamine（PDA）structural color film is constructed on the surface of cotton fabrics.Five different structural colours were prepared by controlling the polymerisation time of dopamine.The microscopic morphology of the PDA structural colour film with a bilayer structure was investigated by scanning electron microscopy（SEM）,and the addition of PVP effectively reduced the breakage of the PDA film.FTIR,XPS results demonstrated that theγ-lactam group of PVP formed a strong hydrogen bond with the catechol of PDA.The effects of PVP concentration on the colour rendering effect,washing fastness and abrasion fastness of PDA structured cotton fabrics were investigated by K/S,UV reflectance spectroscopy,rubbing and washing tests.The experimental results showed that the PDA structured coloured cotton fabrics with 1.0 wt%PVP had high saturation and colour fastness.（2）SiO₂ nanospheres with good dispersion were prepared by sol-gel method,and the non-iridescent structural color coating was prepared by wrapping the PDA layer on the surface of Si O₂ microspheres by the autopolymerization reaction of DA,and the Si O₂@PDA non-iridescent structural color coating without angle Si O₂@PDA dependence was successfully prepared on cotton fabrics by SEM,reflectance spectroscopy,K/S and other tests.Inspired by（1）PVP is introduced on the surface of the Si O₂@PDA structural color coating to improve the structural color fastness.The results of FTIR,K/S,ultraviolet reflectance spectroscopy and friction proved that the Si O₂@PDA non-iridescent structural cotton fabric with 1.0 wt%PVP had high saturation and wear fastness at the same time.（3）Hydrophobic and high colour fastness PDA structured colour films were constructed on cotton fabrics by hydrophobic modification of PDA structured colour films with polyvinylsilsesquioxane（PVS）.FTIR,XPS and SEM tests showed the existence of covalent bonds between PVS and PDA,which helped to improve the interfacial bonding strength of PDA structured colour films.The results of contact angle,washing and reflectance spectroscopy show that the PDA structured cotton fabric modified with 6.0 wt%PVS has excellent colour fastness,hydrophobicity and saturation,with a maximum contact angle of 141°.