Open Access Te Herenga Waka-Victoria University of Wellington
thesis_access.pdf (29.38 MB)

Gold and silver nanoparticles as high-value colourants and multi-functional entities for natural fibres and minerals

Download (29.38 MB)
posted on 2021-11-15, 14:08 authored by Burridge, Kerstin Ann

Significant opportunities exist in both the scientific and industrial sectors for the development of novel multi-functional materials that combine the inherent properties of all precursor components in a synergistic manner, thereby providing new products and opportunities. Processes that add value to natural materials in a facile and refined manner are particularly sought after. Thus this research combines useable substrates, notably natural protein fibres and minerals with gold or silver nanoparticles, producing high value, multi-functional materials that display the strength, softness and shine (of the protein fibres), or high surface area and dispersibility (of the minerals) with the high value and wealth associated with the noble metal nanoparticles, their broad spectrum of intense colours, anti-microbial, insecticide and anti-static properties. This adds significant worth to the substrates, transforming them from commodities to valuable materials.  Silk, merino wool and crossbred wool were the natural fibres employed kaolinite and halloysite clays the minerals. They were combined with gold and silver nanoparticles of various sizes and shapes (and hence colours) producing the following composite materials:  • Gold nanoparticle-merino wool composites  • Gold nanoparticle-crossbred wool composites  • Gold nanoparticle-silk composites  • Silver nanoparticle-kaolinite composites  • Silver nanoparticle-halloysite composites  The most successful method for producing silver nanoparticle-clay composites involved the external preparation of silver nanoparticles and their subsequent attachment to the clay substrates by means of a layer-by-layer deposition approach, which capitalised on electrostatic interactions between oppositely charged polyelectrolytes capping the nanoparticles and bound to the clay surfaces.  Three general approaches were employed in the production of the gold nanoparticle-natural fibre composite materials. The nanoparticles were either synthesised ex-situ and subsequently attached to the fibres, or the natural fibres were utilised as redox active biotemplates in which the wool or silk absorbed and subsequently reduced Au³⁺ to nanoparticulate Au⁰ on and within the fibres. Thirdly, a seed mediated growth approach was employed in which additional Au³⁺ was reduced to nanoparticulate Au⁰ on the surface of gold nanoparticles already bound to the fibres. This was facilitated by an external reductant.


Copyright Date


Date of Award



Te Herenga Waka—Victoria University of Wellington

Rights License

Author Retains Copyright

Degree Discipline


Degree Grantor

Te Herenga Waka—Victoria University of Wellington

Degree Level


Degree Name

Doctor of Philosophy

ANZSRC Type Of Activity code

970103 Expanding Knowledge in the Chemical Sciences

Victoria University of Wellington Item Type

Awarded Doctoral Thesis



Victoria University of Wellington School

School of Chemical and Physical Sciences


Johnston, Jim; Borrmann, Thomas