Nano-particle Size Analyser, Zetasizer and Vibrating Blade Viscometer
About the Instrument:
The nanoparticle size analyser and zetasizer measures particle size from 0.6 nanometres (about six to ten atoms in a row) up to 0.2 microns and the surface charge or zeta potential of any sized particle that can be suspended in liquid. Neatly contained in a compact unit, it is accurate, reliable and easy to use. It comes with an auto-titrator – a reaction flask connected to the analyzing unit – which allows you to add accurate amounts of different chemical reagents into the sample solution as it is being analysed. The auto-titrator includes a magnetic stirrer and pH electrode. Measurements can take as little as ten minutes to complete and all parameters are controlled via a user friendly computer interface. The set up also includes a vibrating blade viscometer to measure the viscosity of solutions. It can measure low viscosity solvents such as water and has a built-in thermometer for temperature readings. It is very easy to use. An older particle size analyser in the same lab measures the size of larger particles from 0.02 micrometers up to 2 millimetres and complements the zeta-sizer.
This system has transformed the capability of several groups at Victoria University. Researchers use it to find the average size and charge of the nano-particles and quantum dots which they synthesise in solution – essential information for developing commercial applications. The instrument is a perfect complement to the electron microscopes, also housed at Victoria University, which give detailed information on the size and shape of individual particles. It’s a piece of equipment that we’ve wanted for a long time,” says Victoria University chemist Jim Johnston. His group are combining nanoparticles and quantum dots with natural fibres and other fabrics to produce new ‘nano-hybrid’ materials with interesting optical, chemical and magnetic properties. The new instrument is essential for the development process. PhD student Andreas Zeller from Germany is developing quantum dots that glow different colours when exposed to UV light. “My big idea,” he says, “is put the quantum dots on a white shirt and it turns orange when the UV radiation of the sun is too strong. So children playing outside will know it’s time to go indoors.” These quantum dots could also be used to make invisible bar codes or high visibility sportswear. As he explains the key to many of these colour applications is particle size: “By changing the size of the quantum dots and the nature of the host material and dopant, we get different colours which range from red, orange, yellow, green and blue.” Andreas changes the size by tweaking his synthesis technique and the zetasizer provides a quick, easy way to monitor the effects. The auto-titrator provides a way to distinguish between individual particles and agglomerates and measure the size of both. You can even use the auto-titrator to synthesise nanoparticles and watch them change size as you add different chemical reagents.
“We’re always open to collaboration,” says Jim. “The old saying, the sum is greater than the parts, is very true.” The instrument is open to researchers from inside or outside the Institute whether collaborating with the group or working independently. It is already being used by three groups at Victoria University to analyse nano-particles and liquid-based self assembling systems such as emulsions. MacDiarmid funded post-doctoral fellow, Dr Carla Fonseca, is happy to train researchers and assist collaborations and a user manual has been compiled to help new users get the most out of the system.