Designing the materials of the future
Monday, Nov 9, 2015, 04:42 AM | Source: Pursuit
By Greg Qiao
When we hear the term 'polymer', many of us think of plastic, the ubiquitous product that fills our shopping aisles, homes and offices. We may also think of the risk that everyday plastics have in clogging our oceans, killing our marine life and polluting our environment. So you may be surprised to learn that research into polymers is creating revolutionary new materials that can be used to improve both human and environmental health.
A polymer is a large molecule, composed of many repeated smaller molecules or monomers. Polymers can occur in nature, such as in the cellulose that constitutes paper or wood, or the DNA and proteins found in the human body. Polymers can also be synthesised into the plastics we are so familiar with, such as polystyrene. Whether natural or synthetic, polymers share a range of unique characteristics, such as durability, strength and flexibility, which can be harnessed in a variety of useful ways.
The University of Melbourne's Polymers Lab houses more than 22 research fellows and PhD students from the Department of Chemical and Biomolecular Engineering's Polymer Science Group. Polymer Science Group leader Professor Greg Qiao said that the central focus of the group is the creation of new generation polymers, which have diverse applications in areas such as nano-medicine, carbon capture and storage, and environmental management.
Innovations that will benefit the environment include new materials for gas separation membranes for carbon capture, ultra-thin films capable of protecting water supplies, such as reservoirs and dams from evaporation, and renewable energy through the development of new biofuels.
CLEan carbon technology
Professor Qiao has developed a new membrane for carbon capture that is thinner, stronger and more permeable – creating a better, cleaner and cheaper way of capturing carbon, with less leakage and waste.
Essentially we have established a new method to make gas separation membranes that could be a new benchmark for industry.
Currently the membranes are being trialled in the US and will be trialled next year at the CRC for Carbon Capture and Storage (CO2CRC) demonstration plant in the Otways, Victoria. The Otways facility demonstrates how the pollution from a power plant could be mitigated, by taking naturally occurring carbon dioxide from the atmosphere, liquefying it, and sending it for storage underground.
According to Professor Qiao, improved membranes performance could be used for a range of industrial processes.
"It is not just about CO2 separation, gas separation is needed for many other industries and these membranes can be tuned to filter out whatever is required," Professor Qiao says.
Saving our water and coral reefs
Dr Emma Prime is another researcher in the Polymers Lab, who has been leading some projects to benefit the environment. Dr Prime has been focusing her research on creating monolayers, which are ultra-thin films formed at the interface between air and water. These monolayers resemble ultra-thin blankets that can be used to coat the surfaces of dams and reservoirs to prevent water loss through evaporation. Field tests are currently underway, but these chemical blankets promise to be a more environmentally friendly solution than covering our waterways with black plastic balls.
Dr Prime is also using monolayer technology in a project to reduce bleaching of coral on the Great Barrier Reef. This ultra-thin film technology reduces the incidence and severity of coral bleaching by decreasing the amount of light entering the water, helping maintain the reefs and the enormous biodiversity they harbour, as well as protecting the livelihood of an estimated half a billion people worldwide.
Creating new biomaterials
Other fundamental research being conducted by the Polymer Science Group lies in the area of biomaterials, particularly, in building new scaffolds for tissue engineering, and in making polypeptides – i.e. polymers from amino acids, which make up protein. A big advantage to working with amino acids or protein is that being biocompatible with the body, the material is safe to use as a carrier for many different kinds of drugs inside the body. It is also naturally occurring, sustainable and environmentally friendly.
In the tissue engineering space, Professor Qiao and his team have been developing synthetic cornea replacements.
When the inner layer of the adult cornea is infected or damaged, it does not regenerate. The current way of treating this, is to replace the inner layer with one from a donor. This requires an extremely delicate operation, and the donor cornea can be damaged in the process, or be rejected by the recipient.
In collaboration with Centre for Eye Research Australia (CERA), Professor Qiao's group has developed a technique to grow replacement cornea tissue, using the patient's own cell tissue, which removes the possibility of rejection of the implant and means that if the cornea breaks, it is easy to replace. Another advantage of the synthetic cornea is that it is stronger than the original and less prone to breakage.
Finding better treatments for disease
In the area of polypeptide research, the Polymers Lab is currently working on two key areas. The first is an ARC funded project to investigate safer drug delivery mechanisms for treating cancer.
"Researchers have synthesised a star-shaped polymer derived entirely from naturally occurring amino acid building blocks, which can be used specifically to target cancer cells, leaving healthy cells unharmed," Professor Qiao says.
The second is another ARC funded project in collaboration with Melbourne's Dental School, which looks at using polypeptides to fight bacteria. Professor Qiao and his team have produced polymers that are capable of killing deadly superbugs, which could provide an alternative to antibiotics.
We have conducted a trial in which we could see that our star shaped polymer successfully killed bacteria, not only before antibiotic resistance had developed, but afterwards as well.
This research could make an enormous contribution to counteracting the serious threat to human health posed by modern day superbugs caused by antibiotic resistance.
These are just a few examples of how the chemical and biomolecular engineering research conducted at the Polymer Science Group is helping to create the next generation of materials to solve challenges in human health, the environment and energy, proving that polymers are so much more than plastic.
Banner image: Students in the Polymers Lab byJoe Vittorio.