VTT Technical Research Centre of Finland is developing new techniques for the production of metallic nanoparticles. VTT's new production reactor, operating at atmospheric pressure, reduces the production costs of multicomponent particles. It enables the production of metallic nanomaterials, which are not yet commercially available, for research and product development needs.
The most significant applications for metallic nanoparticles currently have to do with the utilisation of their optical and magnetic properties, conductive inks and catalysts – and these are also the primary areas of focus in the related development work. In the future, optically transparent coatings will make it possible to replace precious metals with copper in, for example, solar cells, opto-electronics, and diagnostics.
Also in the manufacturing of conductive inks, the major focus of interest is the replacement of silver with copper, which is significantly cheaper. In this field, the small size of the particles affects, for example, their sintering properties, stability of the inks, and printability.
The magnetic properties of metallic nanoparticles are considerably stronger than those of oxides, which are currently being used in the industry. In addition, the use of alloy metals makes it possible to customise particle properties to meet the needs of each application. Potential applications include, for example, data storage, magnetic polymer composites, sensor and machine actuators and, in the long term, even the treatment of illnesses.
Since VTT's new reactor operates at atmospheric pressure, its construction and usage costs are low. The process is continuous, and affordable source materials can be used. The wastage rate is low, while the produced powders are pure. The reactor is particularly well suited for the production of alloy metal nanoparticles. The particle coating protects the particles from aging during handling and storage, also making it possible to combine organic compounds with metallic particles.
Ari Auvinen, Principal Scientist at VTT, reckons that the next nano-innovations from Finland will be related to conductive inks, magnetic polymers, and catalysts. Commercial production of particles also creates interesting business ortunities. "3D printing is currently in increasing demand, and in the coming years, the demand for metallic materials suitable for use with printers is also likely to arise," Auvinen says.
Besides commissions from companies, VTT uses its equipment for public research projects. A special development project is the combination of nanoparticle technology with printing and sensor technologies.