Published on December 14th, 2009 | by Tina Casey2
Gold Nanoparticles Could Lend Green to Fabrics and Fragrances
A team of Harvard scientists has discovered that gold nanoparticles could be used to produce fabrics and fragrances. The process is cheaper and more energy efficient, and it emits fewer pollutants than conventional production methods. The breakthrough is more proof that sustainable manufacturing methods can achieve bottom line benefits along with improvements in public health and environmental safety.
Headed by Professor Cynthia Friend, the team found that gold nanoparticles can oxidize alcohols and aldehydes (formaldehyde is a familiar example of an aldehyde) at room temperature. The process uses less energy than the high heat required by conventional methods. If the process can be scaled up for commercial use, it could significantly reduce the carbon footprint involved in manufacturing synthetic fabrics, fragrances, essential oils, and perhaps other products as well.
Cheaper, Greener Fabrics and Fragrances
As reported by writer James Urquhart in Chemistry World, gold nanoparticles would replace conventional, energy intensive stoichiometric oxidation processes. Stoichiometry refers to the relationships within chemical reactions, and oxidation is one of the most common reactions used in manufacturing. It produces a wide range of products from cleansers to fertilizers. The Harvard team is among numerous scientists searching for a more energy efficient and less polluting process. They focused on gold nanoparticles as a way to get the job done at lower temperatures. They also found that the reactions take place on the nanoparticle surface, reducing the emission of pollutants from extraneous reactions. The process yields a more energy efficient way to produce esters, which are the ubiquitous fats and oils that are used in fragrances and essential oils. Esters are also used to produce explosives (think nitroglycerin) and plastics used in common synthetic fabrics such as cellulose acetate and acrylic.
The Right Tools for the Job
Scaling up the gold nanoparticle process for commercial use is one major hurdle, and another team of Harvard researchers may have the key to that. They are working on a more precise way to manipulate gold nanoparticles using surface plasmons, which are the oscillations formed between the surfaces of two different materials. The effect can be produced to study nanoscale changes in a material, including fluctuations in its thickness and density, and the accumulation of molecules on its surface.
Rediscovering Gold Nanoparticles
Professor Friend’s team found that the surface of gold nanoparticles could bond with oxygen to break down methanol, forming methyl esters. This atomic-level knowledge was unavailable to medieval church architects, but they may have put the principle into practice. A Queensland University scientist has found evidence that gold nanoparticles used in medieval painted glass windows can purify air. In this process, sunlight creates an electromagnetic field that resonates with the gold nanoparticles, destroying volatile organic compounds.
Image: Gold coins by Mykl Roventine on flickr.com.