The Fabrication of Biomimetic Structurally Coloured Textile Materials by the Sedimentation of Monodispersed Silica Microspheres

Natural precious opals consist of silica microspheres of uniform mean diameter organised in a periodic three-dimensional structure. The physical structure of the material produces the perceived colour by a process of light interference. The modification of light by the physical structure of the material is also known as structural colour. This is a different process from how most surface colours are produced wherelight is more usually absorbed by dye and/or pigment molecules. Desirable aesthetic qualities could be achieved if the structural colours produced by natural opals could be replicated in the form of a film or a coating on textile substrates. The work presented investigates how to produce coloured textiles using surface applications of monodispersed silica microspheres. A novel one-step technique has been used to produce monodispersed silica particles with particle diameters ranging from 70 nm to 400 nm. Using mono dispersed particle solutions, artificial opal films have been fabricated by a process of natural gravity sedimentation. It was determined that those samples having uniform particle populations in the range of 207 nm to 350 nm resulted in coloured films. The sedimentation of silica particles onto cotton fabric, of a particular particle size range, produced a coloured fabric. Depending on the mean particle diameter a range of coloured fabrics may be obtained. The light fastness properties of the coloured textiles were investigated.