School of Chemical and Physical Sciences and
MacDiarmid Institute for Advanced Materials and Nanotechnology,
Victoria University of Wellington, Wellington, New Zealand
Professor J.H. Johnston and Dr. K.A. Lucas have recently developed a novel approach for dyeing merino wool with gold nanoparticles by coupling the surface plasmon resonance and the chemistry of gold with that of wool fibres. In a related approach presented here, the research is carried out in three major steps: (a) formation of gold nanoparticles, (b) preparation of wool surface for dyeing process and (c) fabrication of nanogold-wool-composite. The synthesis of red colloidal gold uses reducing agents such as tannic acid. Purple and blue nanogold forms in the presence of other reducing agents and/or surfactants.
Seeded-growth-processes allow a wider colour tuning through different particle shapes. Two-phase-processes achieve a beneficial functionalisation of the particle surface. Steps (b) and (c) transfer the outstanding optical properties of nanogold onto wool resulting in durable, non-fading coloured fibres. Characterising studies of all production stages are mainly performed by electron microscopy, visible absorption spectroscopy and dynamic light scattering techniques. Investigations focus on size and shape of nanoparticles, their distribution on the wool surface and the fibre morphology. This novel dyeing process has the potential for colouring wool for high value textiles.