Meet the Innovator Battling Plastic Waste in Singapore: Hai Minh Duong

Tell us about yourself, and your project.

My name is Hai Minh Duong. I’m an Associate Professor at the Faculty of Engineering, National University of Singapore (NUS) and I’ve been researching engineering applications of lightweight materials since I received my Ph.D. in 2004. 

My team at NUS developed Polyethylene terephthalate (PET) aerogels, converted from plastic bottle wastes. Aerogels are the lightest and most porous materials on earth and have existed since the 1930s.

The PET aerogel is the strongest and “sexiest” version of aerogels. It helps address the plastic waste problem we are facing today and has many real-life applications that can benefit everyone. These applications include heat and sound insulation, CO₂ and dust particle filtering, personal care such as diapers, medical devices and oil and non-polar liquid absorption. There were more than 1,600 oil spills on Singapore’s roads in 2015. Our aerogels are four times more effective than commercial products in terms of absorbing oil spills and are a potential solution to speed up the cleaning process and reduce costs. After they are finished absorbing oil spills, you can squeeze the oil out and reuse them! 

Is there any concern with this new material?

People say at the end of the day, PET aerogel is still PET. But PET bottles take 500 years to degrade, while PET aerogels do so 20 times faster than that because the bottles are converted into fiber. Also, after production, we release only water into the environment. We don’t release any toxins or chemicals into the environment. 

How is plastic waste an issue for oceans and waterways in Singapore?

It is reported that Singapore uses at least 1.76 billion plastic items a year – or almost one plastic item per person per day – but less than 20% of that is recycled. Research also found that Singapore uses 467 million PET bottles a year and 473 million plastic disposable items such as takeaway containers.  

Globally, such plastic waste often ends up in landfills, uncontrolled dump sites, and oceans, which therefore cause problems for marine life and groundwater. 

When were you first interested in this issue?

At the NUS canteen, we need to pay 10 cents for each plastic bag. I wondered, why do people still use so much plastic and not recycle it? Then I realized, it’s because plastics are so cheap and convenient, so people use and throw them away so easily. They don’t recycle because they don’t see the value of it. 

Therefore, my idea was to convert plastic waste into high-value materials. For example, every time you put away a plastic bottle, I can recycle it into a forty-dollar product. You will keep it, and you will sell it to me. And that’s how plastics will not end up in the ocean anymore. 

What do you hope your work can achieve?

I wanted to come up with a real product for everyone, after a lifetime spent producing theories. As countries struggle to cope with growing piles of plastic and other waste, my invention showed that engineering and technology can offer solutions. 

For example, in highly urbanized countries like Singapore, carbon dioxide absorption masks and heat-resistant jackets made from PET aerogels can be placed alongside fire extinguishers in high-rise buildings to provide protection to civilians when they escape from a fire. Masks lined with amine-reinforced PET aerogels can also benefit people living in countries such as China, where air pollution and carbon emission are major concerns.

What motivates or inspires you?

I used to wonder when I saw oil and plastic waste on the beach: “Can we use the rubbish on the beach to clean the oil spills?” Imagine a solution to turn plastic waste that ends up in landfills and oceans into high-value engineering applications. And honestly speaking, with the amount of existing plastic waste in the world’s oceans, there is no shortage of raw materials that could be recycled into aerogel products! 

Our team has dreamed of reducing environmental waste through our research and innovations. Now we are hoping to see PET aerogels be mass-produced next year.

For more information on PET aerogels, visit Professor Duong’s website: https://haimduonglab.com/