Professor Rachel Caruso is harnessing the power of nanoparticles to fight pollution and protect our environment.
As Director of RMIT University’s Advanced Materials Enabling Capability Platform, Caruso works with a range of scientists and engineers researching new or existing materials that are modified to obtain superior functional or structural performance.
She is passionate about finding ways of doing this which benefit the environment.
One of her current research projects is developing sponges made of nanoparticles that remove toxic pollutants from water.
These porous materials are made of the same stuff many Australians put on their face when they slip, slop, slap during our scorching summers – the titanium dioxide found in mineral sunscreen.
Titanium dioxide is cheap and abundant in Australia, as well as environmentally safe. With some modification it absorbs toxic metal ions in water, and it reacts to light, breaking down organic pollutants when they come into contact.
But being so small, titanium dioxide nanoparticles are difficult to remove from water, and therefore can become pollutants as well.
In an elegant work-around, Caruso and her fellow researchers have harnessed and enhanced the nanoparticles’ individual powers by building them into controllable porous structures.
Using sponge-like structures as templates, the researchers produce nanoparticles within the template and then remove it, which results in porous sponges. This method gives control over the porosity and surface area of the material.
“The idea we have is to use these structured materials rather than the individual nanoparticles. Putting such a material into a polluted water stream provides a similar surface and contact area for collecting the pollutant, while being easier to handle,” Caruso says.
“When you are looking at making larger quantities you don’t want too complex a synthesis process – you want to be able to make the materials easily, and control some of the properties so you can get the maximum benefit from the material that you are using.”
Potential end-users for the porous sponges include textile industries that use chemical dyes to colour fabrics, and then need to clean the run-off waters. Dyes can be broken down into harmless molecules through contact with the nanoparticles under light.
“To prevent dye from flowing out into the water stream, you would treat the water before it was discharged,” Caruso says.
While product development is still a way off, Caruso and her colleagues are already considering additional uses. Other poential applications include using the porous sponge structure as an electrode in batteries and solar cells, to improve renewable energy usage.
Building collaborations and interdisciplinary research is something that excites Caruso the most about being at RMIT.
“At RMIT there are a range of disciplines that have a materials focus,” she says.
“If people from these different disciplines talk together, share their expertise and work towards common goals I think there is the potential to innovate and grow our capabilities.”
Story: James Giggacher