These particles promise to be more cost effective and better at absorbing light than the gold nano-products which are currently used.
Terry Bigioni, a chemist at the University of Toledo in Ohio, said that the new processes “bode very well for manufacture.”
Nanoparticle technology is increasingly used in the cosmetics industry, in items ranging from sun cream to skin care products.
An independent discovery
Two teams independently discovered the similar recipes for manufacturing silver nanoparticles: one led by the chemist Nanfeng Zheng at Xiamen University and another led by Bigioni at the University of Toledo in Ohio.
Metal nanoparticles are sometimes used to create a smooth, uniform appearance because the tiny particles constantly reflect light. Each particle used is around 3 nanometers long, giving it very different properties to bulk-sized metal.
Silver was unpopular for this purpose because it tarnishes much more easily than gold, meaning that silver nanoparticles have a much shorter shelf life.
However, the nanoparticles developed by the two teams use a “shell” of silver atoms and sulphur molecules to support an organic layer which stops the core of the particle from being affected.
The recipes use cheap silver nitrate, water and ethanol and are described as being able to produce “hundreds of times more than routes to other nanoparticles” as stable particles which can be used.
The particles will also reflect more light than their gold counterparts, giving a smoother appearance to the cream.
A new frontier
Nanotechnology, which uses nanometer-scale objects to create various effects, promises great benefits in the fields of medicine, formulation and materials technology.
In the field of cosmetics, they are used for a variety of purposes including reflecting light, as preservatives and to deliver active ingredients through several layers of skin.
The silver nanoparticles could also be used for wound dressings and other medicinal purposes.