Changing the world one molecule at a time: 2011 Prime Minister’s Prize for Science

Ezio Rizzardo and David Solomon

In the coming years when you buy a tyre, lubricant, adhesive, paint, computer or any one of hundreds of other products, there’s a good chance that some of its component materials will have been produced using revolutionary chemical theories and processes invented in Australia by research teams led by Professors Ezio Rizzardo and David Solomon.

Their techniques are employed in almost every university chemistry department, and the laboratories and factories of DuPont, L’Oréal, IBM, 3M, Dulux and more than 60 other companies.

Their work has been cited more than 12,000 times in the scientific literature and is an integral part of more than 500 patents and counting. The processes developed by the duo will influence the production of about half the tonnage of polymers—mainly plastics—encountered in everyday life.

However it wouldn’t have happened without the meeting of two great minds at CSIRO. One is David Solomon, born in The Great Depression and who began working for a paint company in Sydney at age 16. Now 81, he is still pursuing research as a professorial fellow at the University of Melbourne. The other is Ezio Rizzardo, who came to Australia from Italy as a teenager without a word of English. He entered the world of chemistry as a refugee from medicine, and is now a CSIRO fellow at the Division of Materials Science and Engineering in Melbourne.

Together they were able to harness the power of organic chemistry to provide unprecedented control over the structure, composition and properties of the polymers that are now used in almost every facet of our lives. In essence, they devised a means of custom building plastics and other polymers for tasks at the cutting edge of technology—from producing plastic solar cells to delivering drugs precisely to their site of action in the body. Many of the compounds developed using their techniques would have been inconceivable in the past. And their technologies are also transforming traditional polymer applications such as paints, adhesives and lubricants.

“The impact of this outstanding body of work cannot be overstated,” says Professor Craig Hawker, director of the Materials Research Laboratory at the University of California, Santa Barbara. “It is rewriting the book on polymer synthesis, dramatically impacting many diverse and important areas of academic and industrial research. Their creativity reaches out far beyond the stellar science. I see no limits to what can come from this work and am very proud to be able to say that it is home-grown Australian science through and through.”

For their role in revolutionising polymer science, Professors Ezio Rizzardo and David Solomon jointly receive the 2011 Prime Minister’s Prize for Science.

Polymers are long chains of molecules (monomers) strung together like beads on a string. In traditional plastic production, all the beads were the same molecule and the reaction that strung them together tended to be rapid and uncontrollable—a chain reaction. Solomon and Rizzardo found a way to regulate the speed at which molecules attach to the end of the chain, and thereby to control the order and type of molecules added. This was a quantum leap in sophistication.

David Solomon started work at Balm Paints (later Dulux Australia) in Sydney in 1946 at age 16. The company allowed him half a day off in his 48-hour week to study. In five years he completed a Diploma of Science which over the next decade he gradually upgraded to an honours degree, a masters and finally a PhD in organic chemistry.

For his doctorate, he was given one day off a week, and he also worked on it Saturdays and nights. At the same time he was teaching himself about polymers, which are used as the binders in paints. By the time he completed his PhD, he had filed several patents for a new polymer system and had begun to recognise that the-then current polymer theory was relatively crude and needed updating.

The chance to probe the mechanisms of polymer formation came years later after a job change to CSIRO where, by the mid-70s, Solomon had become the Chief of the Division of Applied Organic Chemistry. He was well on his way to creating Australia’s plastic banknotes—but that body of work, significant in its own right, is not what he is being recognised for today.

He advertised for a postdoctoral fellow to act as his right-hand man in a small polymer research group he was establishing. The researcher he appointed was Ezio Rizzardo.

Ezio came from a family of metal workers. At high school he was keen on a career in developing better car engines, but was advised by a teacher that there was no future in that inAustralia. Instead, he enrolled in medicine, but when in first year he stumbled across a second-year class working on cadavers, Ezio decided he wasn’t destined to become a doctor either.

In chemistry, however, he thrived and, after a PhD at the University of Sydney, he completed a series of postdocs working with biologically active compounds. He synthesised the first active form of Vitamin D while in the laboratory of Nobel laureate Sir Derek Barton in Boston. He also worked at the Australian National University with Professor Arthur Birch, known as ‘the father of the Pill’ because his research opened the way to the first oral contraceptives.

At CSIRO, he and David Solomon began to analyse a means of polymer construction using free radicals—compounds distinguished by a highly reactive unpaired electron. In forming such polymers, a free radical compound acts as an initiator and links with a monomer to form a new free radical molecule. This molecule links with another, starting a chain reaction. Normally this process proceeds rapidly until it is terminated, producing a random mix of polymers of different lengths.

Ezio and David found a way of stopping this polymerisation reaction after just two or three links had been formed. This was a length they could manipulate to analyse what was going on. They did so by capping the radical end of the chain with nitroxide. Using their technique they found out many things that were previously unknown, such as how much influence the compound used as the initiator had on the resulting polymer.

The observation that ended up having the most impact, however, was almost serendipitous. They noticed that, in some cases after stopping the reaction, a colour typical of nitroxide was being released. In fact, they had discovered that the capping was reversible. When the mixture was heated, the nitroxide caps came off and polymerisation could begin again.

Their ‘Eureka’ moment was recognising that through this they could control the speed of polymerisation and regulate the content and structure of the polymer. In 1985, they patented this process and the paper they published on it in 1990 became one of the most widely cited in polymer chemistry. The world, and particularly the US chemical giant DuPont, noticed what they were doing.

Having made the intellectual and conceptual leap of using a reversible process to build polymer chains, Rizzardo and two other colleagues at the CSIRO came up with a more efficient and flexible way to achieve the same thing—reversible addition-fragmentation chain transfer (RAFT). They published their new technique in 1998 and it is now used in virtually every polymer laboratory in the world. The development agreement they signed with DuPont and subsequent patents will, over time, be worth hundreds of millions of dollars to CSIRO.

While the world’s biggest chemical companies are using the process to build ever more sophisticated polymers, Solomon and Rizzardo are hard at work using it in their own projects. David Solomon is developing a one-molecule-thick polymer film which will prevent evaporation from reservoirs and water storages.

As he continues to work on improvements to RAFT, Rizzardo is developing ‘smart’ biomaterials to carry drugs which can be targeted precisely at specific tissues. He is also working on a polymer which will reduce fouling of the membranes used for water purification.

“David Solomon and Ezio Rizzardo have done something rare in science,” says Professor Robert Gilbert of the University of Queensland. “They have created a paradigm shift in the way that polymers can be made.”

Qualifications

1993	Graduate, CSIRO Leadership Development Program
1969	PhD (Organic chemistry), The University of Sydney
1966	Bachelor of Science (Honours), University of New South Wales, Sydney

Career highlights

2011	Ranked 18th in the Thomson Reuters list of the world’s 100 most influential chemists
2011	Named a Luminary of Australian Chemistry by the Royal Australian Chemical Institute (RACI)
2010	Honorary Professorial Fellow, School of Chemistry, The University of Melbourne
2010	Elected Fellow of the Royal Society
2009	CSIRO Medal for Lifetime Achievement
2005	Royal Australian Chemical Institute (RACI) names their Applied Research Award the Ezio Rizzardo Medal
2003	CRC for Polymers Chairman’s Awards for Excellence in Commercialisation (also in 2004 and 2011)
2003	Australian Government Centenary Medal
2003	CSIRO Molecular Science Award for Innovation
2002	Elected Fellow of the Australian Academy of Science
2001	CSIRO Most Prolific Inventor Award
1994-present	Leader, Polymer Production Program in Cooperative Research Centre (CRC) for Polymers
1994	Elected Fellow of the Australian Academy of Technological Sciences and Engineering
1992–1994	Inaugural/Interim Director, CRC for Polymer Blends
1992	CSIRO Chairman’s Medal
1988–1992	Project Leader, Polymeric Biomaterials, CSIRO
1981	Elected Fellow of the Royal Australian Chemical Institute
1980–1998	Manager, Polymers Program, CSIRO
1978-present	Project Leader, Engineered Polymers, CSIRO
1976-present	Senior Research Scientist progressing to CSIRO Fellow (in 2000), CSIRO
1973–1976	Research Fellow, Australian National University, Canberra
1971–1973	Postdoctoral Fellow, Research Institute for Medicine and Chemistry, Cambridge, Massachusetts, USA
1969–1971	Postdoctoral Fellow, Rice University, Houston, Texas, USA

David Solomon

Qualifications

2005	Doctor of Applied Science (honoris causa), The University of Melbourne
1968	Doctor of Science (Chemistry), University of New South Wales, Sydney
1959	PhD (Chemistry), University of New South Wales, Sydney
1955	Master of Science (Chemistry), New South Wales University of Technology, Sydney
1952	Bachelor of Science (Honours), New South Wales University of Technology, Sydney
1950	Associate Diploma of Chemistry, Sydney Technical College

Career highlights

2008	Innovation Award, Society of Plastic Engineers
2007	Elected Fellow of Institution of Chemical Engineers
2006	Victoria Prize, Government of Victoria
2004	Elected Fellow of the Royal Society
2001	Presented Inaugural RACI Solomon Lecture
2001	Australian Government Centenary Medal
1995-present	Professorial Fellow, The University of Melbourne
1994	Clunies Ross National Science and Technology Award, ATSE
1990–1994	Head of School and ICI Australia—Masson Professor of Chemistry, School of Chemistry, The University of Melbourne
1990	Member of the Order of Australia
1989–1990	Deputy Director, CSIRO Institute of Industrial Technologies
1988–1989	Chief of Division, CSIRO Division of Chemicals and Polymers
1987, 1990	CSIRO Medal
1986–1987	Acting Director, CSIRO Institute of Industrial Technologies
1980–1981	Reserve Bank of Australia (secondment)
1975	Elected Foundation Fellow of the Australian Academy of Technological Science and Engineering (ATSE)
1975	Elected Fellow of the Australian Academy of Science
1974–1986	Chief of Division, CSIRO Division of Applied Organic Chemistry
1970–1974	Chief Research Scientist, CSIRO Division of Applied Chemistry
1968–1969	Georgia Kaolin Company, Elizabeth, New Jersey, USA (seconded)
1966	Elected Fellow of the Royal Australian Chemical Institute
1963–1970	Senior then Principal Research Scientist, CSIRO Division of Applied Mineralogy
1959–1960	ICI Paints Division, Slough, United Kingdom (seconded)
1955–1963	Leader, Resin and Polymer Research Section, Dulux Australia Ltd, Sydney
1953–1955	Demonstrator/Teacher Fellow, NSW University of Technology, Sydney
1946–1953	Balm Paints (now Dulux), Sydney

External Links

View a profile of David Solomon at http://www.eoas.info/biogs/P000253b.htm

View a profile of Ezio Rizzardo at http://www.csiro.au/people/Ezio.Rizzardo.html