“Sulphur can be broken down and reconstituted very easily,” Justin explains, “including safely degrading in the environment. Other plastics are too stable, difficult to recycle, and they can take hundreds of years or more to break down.”
Other applications for the polymer include use as a sorbent for cleaning up deadly oil spills in the ocean; as a safer and more effective slow release fertiliser (currently 70 per cent of fertiliser nutrients are not used by the plant and run off as water pollutants); and for removing highly toxic mercury from soil, air and water.
“Because you can easily break and reform the bonds of the polymer, you can use it to clean up water, then convert to something else—mats, walkways, construction materials, and more,” Justin says.
“This means you can extend the lifetime values of the materials and eliminate end-of-life dead-ends—you can continually recycle and repurpose them for a variety of ways that actually benefit the environment.”
“Because there are literally megaton mountains of sulphur available from petroleum refineries, it’s very cheap. In fact, in many cases they’ll pay you to take it away! If we can turn that into valuable and useful things, we are valorising that waste.”
“Sulphur is also highly abundant geologically. It’s one of the most abundant feedstocks on the planet.”
This early research into reinventing and recycling materials was just the beginning, however. With a $10,000 Impact Seed Funding grant received in 2019, Justin and his team have been able to take this revolutionary discovery in directions they did not expect—with the potential for huge positive impacts upon the environment and for global health and wellbeing.
Aim 1: Explore recyclable rubber, plastic and ceramics to support a circular economy—complete
Aim 2: Transform the lives of some of the world’s poorest people and revolutionise e-waste disposal
The effectiveness of the polymer for mercury remediation opens up opportunities to address major challenges both locally and internationally.
“There are a huge range of mercury problems globally we did not know about, and widespread need for mercury remediation,” says Justin.
Australia has some of the worst mercury levels worldwide, in hotspots where there has been heavy industrial activity over many years. An early call for assistance came from the then government department of the Environment and Energy, regarding the use of a mercury-containing fungicide in Queensland sugar cane farming, which was banned in most countries in the 1970s and ‘80s but continues to be used in Australia.
However, the single largest source of the world’s mercury pollution is from mercury-dependent artisanal and small-scale gold mining (ASGM), which makes up 20 per cent of the world’s goldmining. Between 10 and 19 million people use this method of mining, which supports the lives of up to 80 million people across 70 countries, predominantly in Africa, Southeast Asia and South America. Miners mix the mercury with gold-containing materials to form a mercury-gold amalgam, which is then heated, vaporising the mercury to obtain the gold. They use one kilogram of mercury for every 20 kilograms of gold extracted.
The miners often burn the mercury in their own homes, where inhalation of the fumes leads to acute neurological damage and other health disorders for both them and their families, while nearby communities are also affected by the contamination of water, soil, and fish, which is a staple food. Children in these communities not only have neurological damage but may be born without limbs. Yet, the grim alternative for these goldmining families is starvation.
Many of the actions to resolve this major global issue make mercury illegal, which creates more harm than good for the families who depend upon it.
“Our sulphur polymer is excellent at binding to gold,” says Justin. “Not only is it much, much safer than using mercury or cyanide, which is also used by miners, it removes gold from water at a very high yield over 95% per cent recovery, which is actually more effective than mercury.
“We are looking at a few different ways the polymer can be used for this and testing in a remote mine in Australia. Because these communities have very low incomes, it’s essential the solution is cheap, easy to use, and highly accessible.
“Another big challenge is that some of these communities are in conflict zones, so we are also working closely with government agencies and NGOs on deployment strategies. “
These strategies will include making artisanal gold mining part of the formal economy, to help ensure miners are paid for their work.
"Right now, it’s all black market, and some of these miners are trapped in a form of modern slavery,” says Justin.
The same properties making the polymer excellent for gold extraction can be applied to electronic waste (e-waste), which is growing up to three times faster than general municipal waste in Australia. E-waste presents a huge hazard if not disposed of properly, with mercury and lead leaking into the soil, air and water. It also contains valuable metals, such as gold and copper, that can be recovered for reuse.
“Every tonne of electronic circuit boards contains about 200 grams of gold, plus what do you do with all that plastic and glass? As well as the extraction of valuable metals, there needs to be an efficient disassembly and recycling process,” says Justin.
Part of the Impact Seed Funding was used to validate his team’s research into e-waste for more appropriate disposal methods.
Aim 3: Explore applications for wildlife conservation, space discovery and self-driving cars
“Our third research objective is really exploratory, figuring out all the different physical forms we could achieve with sulphur-based polymers,” says Justin.
It’s not just canola oil that binds effectively with sulphur: orange oil and sulphur creates a similarly versatile polymer, but with different colours and transparency that have potential for infrared imaging applications—including wildlife monitoring and conservation, Australia’s emerging space program, and self-driving cars.
“Plastic usually blocks infrared light, but this unique sulphur material lets the light through, meaning it could be used to create much cheaper infrared lenses. These could also be repaired very easily because of the recyclable properties,” Justin explains.
The Impact Seed Funding has helped purchase an infrared camera for the development of infrared telescope lenses to test in wildlife surveillance.
Justin says these are just the type of research projects that benefit most from seed funding.
“They are high-risk, high reward projects that will benefit both the environment and industry, so truly in the spirit of a seed grant.”
While some of Justin’s research has also received funding from the Australian Research Council (ARC), these grants are much more conservatively awarded.
“Many of the nationally competitive grants are heavily weighted toward track record and what has already been done, rather than supporting high-risk, high-reward projects. This makes it challenging to chart a path for truly transformative, blue-skies research.”
“That’s why seed funding like this is so important. It allows us to try new things and bridge the gap to building a track record and attracting much larger government grants.”
“Our work with this polymer is a great illustration of the way in which seed grants can take research in an exciting direction—not only validating seemingly crazy ideas but building confidence to go on. Because the spirit of discovery takes you off on tangents you don't expect at the outset of a project,” he says.
“And having the freedom to fail is every bit as important, because with every single piece of research—even if it doesn’t work—you’ve learnt something valuable.”
The Impact Seed Funding doesn’t only support Justin’s work, but everyone who collaborates in his laboratory as members of the Chalker Research Group within the University’s Institute for Nanoscale Science and Technology in the College of Science and Engineering. This means giving practical experience and encouragement to 14 aspiring new researchers at every level, from first- and second-year students to PhD students and postdoctoral fellows—each with the opportunity to be published authors on projects.
The research to date has already led to three major patents for the new compounds, sold to international firm Clean Earth Technologies, which has now built a pilot plant in South Australia to produce the polymers at scale.
“This provides royalties to the university and jobs to graduates in chemistry and chemical manufacturing, as well as boosting the economy, so it’s very beneficial in multiple ways,” says Justin.
And it’s winning awards: in 2016, Justin was named Young Tall Poppy Scientist of the Year for South Australia; in 2017, Dream Chemistry Award Finalist (one of five globally); in 2018, Eureka Prize Finalist for Outstanding Early Career Researcher, along with the AMP Tomorrow Maker Award; and in 2020, he won the Prize for New Innovators in the Prime Minister's Prizes for Science.
Justin is deeply grateful for the support donors provide for Flinders’ Impact Seed Funding, and also for the commitment the University makes to its Early Career Researchers, noting that the extensive funding his team receives via the College of Science and Engineering is not typical of other Australian universities, including Group of Eight institutions, where researchers are often expected to bring their own funding with them.
The partnership between the University and its family of supporters—including alumni, staff and friends of Flinders—is helping Justin realise his fondest career aspirations, to use innovative chemistry to solve global grand challenges in sustainability.
“My broadest and most ambitious goal is to use synthetic chemistry to impact the lives of those who don’t have the same access to resources to have a fair go in tackling environmental disasters.
“By focusing on inexpensive materials to capture pollution, we can ensure clean air, water and food for everyone in the world, not just those in wealthy nations.”
Justin’s project was one of 10 selected from 75 submissions for Impact Seed Funding in 2019. Impact Seed Funding is designed specifically to support brave new cutting-edge research with the potential to create positive change within our communities.
To make your own contribution to creating a better world, donate today to support Early Career Research.
