Why a pierced bag of water won't leak

Mar 24, 2005

Have you ever filled a ziplock bag with water, sealed it and stabbed a pencil through it?

You might want to try it because, unbelievably, the bag will not leak.

It's everyday concepts like these that Professor Richard Kaner, a visiting Fulbright fellow from the University of California, Los Angeles, is using to help people understand polymers -- the long chains of molecules that can be twisted and moulded into products.

“The reason the bag won't leak is because the polymers in the plastic stretch around the pencil,” he said.

Professor Kaner has spent a majority of his life researching polymers, particularly conducting polymers - unusual plastics that conduct electricity, and he has found that relating chemical concepts to everyday life is very important.

Concepts such as why a mustard packet can be so difficult to open, or why certain garbage bags rip and others don't.

“It all has to do with polymers, and the directions they are oriented in,” he said.

His four-month visit is part of a prestigious scholarship with the Australian/American Fulbright Commission and involves working closely with UOW's Director of Intelligent Polymer Research, Professor Gordon Wallace.

“I have known of Professor Wallace's institute (Intelligent Polymer Research Institute) for a long time -- in fact it is a very famous centre known all over the world,” he said. “He was the first scientist to discover a chiral (left and right handed) form of the conducting polymer called polyaniline.”

After a lengthy application process and a year of preparation, Professor Kaner arrived in Australia in February and has been enjoying every minute of his stay.

“The research team is making some great progress and everyone is extremely friendly and helpful; I'm really loving it here. I'm working with some very talented people and I've never seen such a cohesive research group”.

Professor Kaner has been researching nanofibres of polyaniline. By combining nanofibres with chirality at UOW's Intelligent Polymer Research Institute (IPRI), he hopes to develop sensors that recognise and possibly separate left- and right-handed forms of pharmaceuticals.

“Many drugs today are sold as a mixture of left and right-handed forms where only one of the forms is active and the other is either inactive or may even cause side effects.”

In conjunction with IPRI scientists he has also been developing a way to print conducting polymers.

“We're developing what's called 'smart paper' where your computer doesn't just scan the document, it actually senses it electronically. We're a few steps closer to having your computer actually interact with your documents.”

Professor Kaner completed his PhD in 1984 under the supervision of Nobel Prize winner Alan MacDiarmid. His dissertation research involved developing batteries out of the first conducting polymer, called polyacetylene, which is made from welder's gas (acetylene).

“It's a very interesting polymer but also completely useless!” Professor Kaner said.

“It is not stable in air and gradually degrades. A long standing joke is that the only use for polyacetylene is to produce PhDs!”

However, at a Nobel Prize symposium in honour of Professor MacDiarmid, Professor Kaner noted that it was actually a dual use material.

“It also produces Nobel Prizes!” he joked.Professor Kaner will get a chance to tour Australia with his family while conducting a series of lectures at Monash University, Newcastle University, the University of Melbourne and the University of Tasmania.

He is also organising a lecture to give at UOW with material suitable for general audiences. Watch this space for more information.

Meanwhile, Professor Gordon Wallace has taken his expertise to North Carolina, USA where he is the keynote speaker at The 13th National Textile Centre Forum and the 84th Textile Institute Annual World Conference.

The back-to-back conferences bring together the world's top industrial and academic minds into a single setting to share the latest developments in textile-related research, trends and issues.

Professor Wallace will speak about conducting polymers and their potential applications in intelligent materials systems, and will be joined by a number of educators, students, researchers, retailers, recruiters, designers and industry leaders from around the world.

-RP