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Chemistry

In Episode 1 of Ever Wondered?  Series 2, Dr John Watt visits top Kiwi scientists who are using chemistry to understand and develop solutions to current global concerns.

From petrochemical plastics to green chemistry alternatives

Jeremy Warnes at Scion Research in Rotorua is trying to replace petrochemicals with green chemistry alternatives. One area his group is focusing on is coming up with an eco-friendly alternative to polystyrene. In a Scion lab, Stephanie Weal shows John how to make a polystyrene replacement using a bioplastic made from corn. It may pop like popcorn, but in almost every way, it looks just like good old polystyrene.

But not everyone’s keen on bioplastics made from corn as this inflates the price of the corn crop. As an alternative, Scion are looking at plastics made from wood lignin. Lignin makes up about one-third of a tree and is a waste product of a lot of wood processing. Dr Gareth Lloyd-Jones explains that Scion have high hopes for lignin providing a sustainable alternative to petrochemical plastics. However, the research is difficult and still has a long way to go. Damien Even shows John how wood can be used to reinforce plastics and thereby reduce the amount of petrochemicals being used. This approach allows standard processing procedures to continue.

Watch Episode 1, Part 1

A cleaner alternative for bleaching paper

Paper manufacture is a huge industry with over 300 million tonnes produced every year. To make the paper white, vast amounts of chemicals are used to bleach it from brown. Typically, the chemicals used are chlorine based and produce environmentally harmful organochlorides as a byproduct.

John goes to Auckland to meet Associate Professor James Wright as he’s interested in finding a safer and cheaper way to bleach paper using hydrogen peroxide. The challenge with hydrogen peroxide is to find a catalyst to speed up the reaction. James explains to John the inspiration and the chemistry behind the effective catalyst for hydrogen peroxide that he’s produced. Then using purple dye, James demonstrates the effectiveness of his catalyst in bleaching the dye colourless with hydrogen peroxide. Versions of his catalyst are already being used in America in the toxic waste and laundry powder industries.

Watch Episode 1, Part 2

Does photosynthesis have an answer to our energy needs?

John then visits the Photosynthesis Research Group at Otago University and meets Associate Professor Julian Eaton-Rye. Here, John finds out why photosynthesis is widely regarded as the Holy Grail in biochemistry and how it may hold some of the answers to our energy needs. Julian explains his fascination with the question: How is a plant able to utilise light from the Sun to split the water atom, separating the oxygen from the hydrogen, and creating energy? This is one of the questions that Julian is investigating to provide some incredible ideas for alternatives for our energy needs.

While there, John meets postdoctoral fellow Dr Martin Hohmann-Marriott, who is investigating photosynthetic bacteria (cyanobacteria) as a potential energy source. He shows John how he’s been able to test that these bacteria are able to use their own natural chemical processes to produce an electrical charge. At this early ‘proof of concept’ stage, Julian explains that the potential of the project is unknown.

John also meets PhD student Ryan Hill who is producing butanol from photosynthetic bacteria. Traditionally, butanol is a fossil fuel derivative. It is also a replacement for petrol. The work that Ryan has done modifying these bacteria to produce butanol is an exciting project, and there is already commercial investment in this work. The future is looking bright for Ryan and his research.

Watch Episode 1, Part 3

Activity idea

In conjunction with this episode of Ever Wondered?, teachers might find useful this information about alternative conceptions about energy.
Alternative conceptions about energy

Context link

Future Fuels: For more information about alternative energy sources, visit this Science Learning Hub context.
Future Fuels

Potatopak is an innovative New Zealand company that makes biodegradable products. They make disposable plates and trays from waste starch. These products are biodegradable and sustainable. In contrast, plastic disposable plates and containers are convenient and cheap, but they are not biodegradable and are made from limited petroleum stocks. To further investigate innovative product development for an alternative to plastic, check out this Biotech Learning Hub focus story.
www.biotechlearn.org.nz/focus_stories/potato_platesexternal link

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