News | Warwick Chemistry | University of Warwick

27 Sept 2007

Membranes do the trick

Researchers in the UK and New Zealand have shown that using a membrane could help catalysts operating in the same system work more efficiently.

Schematic of the catalytic process

The team, led by Paul Taylor at the University of Warwick and Andrew Livingston at Imperial College London, used a membrane to keep catalysts in environments where they work best.

Taylor explained that in a process where two or more catalytic steps are combined in one operation, called a tandem catalytic process, the catalysts normally have to compromise on their performance. This is because the same operating conditions are imposed on both catalysts. 'We use technological tricks to avoid the compromise,' he said, 'and allow the catalysts to operate under their respective optimum conditions, while in terms of the process they are in the same synthetic operation.'

"We use technological tricks to avoid the compromise, and allow the catalysts to operate under their respective optimum conditions"
- Paul Taylor, University of Warwick

The team used the membrane in a tandem catalytic process called dynamic kinetic resolution, a process used to make enantiomerically enriched products. Jonathan Williams, professor of organic chemistry at the University of Bath, explained that, although there are many opportunities for using catalysts in tandem catalytic processes, there are practical problems associated with their use because of the different conditions they require. 'These researchers have provided an elegant solution to this problem by using a membrane to retain an enzyme catalyst in a lower temperature vessel whilst metal-catalysed racemisation occurs in a higher temperature vessel, leading to an effective dynamic kinetic resolution process,' he said.

The partnership involved collaboration between chemists interested in tandem catalysis and chemical engineers interested in membrane technology. Taylor explained that the collaboration resulted from effective networking with colleagues in industry interested in membrane separation.

Katherine Davies

Link to journal article

Towards a continuous dynamic kinetic resolution of 1-phenylethylamine using a membrane assisted, two vessel process
Chayaporn Roengpithya, Darrell A. Patterson, Andrew G. Livingston, Paul C. Taylor, Jacob L. Irwin and Mark R. Parrett, Chem. Commun., 2007, 3462
DOI: 10.1039/b709035h

25 Aug 2007

Bacteria Genome Research Could Save Orchards and Assist Blood Transfusions

Research led by the University Warwick into the genomes of two bacteria could save orchards from a previously almost incurable disease and also assist in treating complications arising from human blood transfusions.

The researchers were interested in how the bacteria naturally produced a family of chemicals called desferrioxamines. Desferrioxamine E is produced by the bacterium Erwinia amylovora. The bacterium uses it to damage apple or pear trees and acquire iron from them. This allows it to establish an infection that leads to the economically-damaging agricultural disease known as “Fire Blight” that can sweep through an orchard if the infected trees are not removed. The bacterium Streptomyces coelicolor produces desferrioxamine B, which is used to treat iron overload in humans – for instance following extensive blood transfusions.

By studying the genomes of the two bacteria, the researchers were able to work out that each uses a similar biochemical pathway to produce desferrioxamines. In both cases they use a “remarkable” trimerisation-macrocyclisation reaction cascade in the key step. The researchers purified the enzyme responsible and showed that it could catalyse the reaction cascade in a test tube.

The current industrial process to create desferrioxamine B relies on the fermentation of the bacterium Streptomyces pilosus. The Warwick-led research has identified how Streptomyces bacteria create it using only four enzyme catalysts and four different building blocks. In contrast, the laboratory synthesis of desferrioxamine B requires 10 steps and uses numerous chemicals. Harnessing the enzymes may result in much cheaper pharmaceuticals based on desferrioxamine B and manipulating them could lead to the creation of new orally-active analogues of this important pharmaceutical.

The new understanding of how desferrioxamine E is created by Erwinia amylovora opens the way for the creation of new chemical inhibitors that may prevent this bacterium from inflicting Fire Blight on orchards

The research was led by Professor Greg Challis from the University of Warwick and involved colleagues from the University of Warwick and the Universidad Nacional Autonoma de Mexico. It was published online in Nature Chemical Biology on Sunday 19^th of August.

For further information contact:

Professor Gregory Challis, Department of Chemistry, University of Warwick
G.L.Challis@warwick.ac.uk
Tel: 02476 574024

Richard Fern, Press Officer, University of Warwick
024 7657 4255 or 07876 217740 email: r.w.fern@warwick.ac.uk

Peter Dunn, Press and Media Relations Manager, University of Warwick
Tel: 024 76 523708 or 07767 655860 email: p.j.dunn@warwick.ac.uk

PR73 PJD 20^th August 2007

26 Jul 2007

Nanotech Clay Armour Creates Fire Resistant Hard Wearing Latex Emulsion Paints

Researchers at the University of Warwick's Department of Chemistry have found a way of replacing the soap used to stabilize latex emulsion paints with nanotech sized clay armour that can create a much more hard wearing and fire resistant paint.

To date latex emulsion paints have relied on the addition of soaps or similar materials to overcome the polymer parts of the paint's aversion to water, stabilize the paint, and make it work. The University of Warwick chemistry researchers led by Dr Stefan Bon have found a simple way to individually coat the polymer particles used in such paints with a series of nanosized Laponite clay discs. The discs effectively create an armoured layer on the individual polymer latex particles in the paint. The clay discs are 1 nanometre thick by 25 nanometres in diameter (a nanometre is one billionth of a metre).

The Lapointe clay discs can be applied using current industrial paint manufacture equipment. They not only provides an alternative to soap but can also be used to make the paint much more hard wearing and fire resistant.

The process devised by the Warwick team can be used to create highly sensitive materials for sensors. The researchers can take closely packed sample of the armoured polymers and heat it to burn away the polymer cores of the armoured particles leaving just a network of nanotech sized connected hollow spheres. This gives a very large useful surface area in a very small space which is an ideal material to use to create compact but highly sensitive sensors.

Their research is in a paper enitled "Pickering Miniemulsion Polymerization Using Laponite Clay as a Stabilizer" by Stefan A. F. Bon and Patrick J. Colver and is published as the cover article in Langmuir. The ACS Journal of Surfaces and Colloids Vol. 23, Issue 16 July 31.

See: http://pubs.acs.org/cgi-bin/article.cgi/langd5/2007/23/i16/pdf/la701150q.pdf

For further information please contact:

Dr Stefan Bon
Associate Professor of Polymer Chemistry
Department of Chemistry. University of Warwick
Tel: 024 7657 4009 Email: S.Bon@warwick.ac.uk

Peter Dunn, Press and Media Relations Manager,
Communications Office, University House
University of Warwick, Coventry CV4 8UW
Tel: 024 76 523708 or 07767 655860
email: p.j.dunn@warwick.ac.uk

PR65 PJD 26th July 2007

23 Jul 2007

Warwick Chemistry Researchers popular in Downloads

The Warwick Chemistry paper by the Sadler group on Metals in membranes published in Chem. Soc. Rev. was in the top 10 of this journal's downloads and the Haddleton group scored with Polymer-Protein/Peptide Bioconjugates in Macromol.Rapid.Commun. an impressive number one position in this journals top downloads!

13 Jul 2007

PhD student becomes vice-chair GRC Master Class

Catheline Colard, a first year PhD student in the Bon research group, has been voted vice-chair of Gordon Research Conference on Polymer Colloids 2009 Masterclass. This masterclass is a two day event organised before the Gordon Research Conference on Polymer Colloids in 2009. Catheline will help to organise the programme.

12 Jul 2007

Warwick Chemistry popular on Youtube

Julie Macpherson's group Warwick ICAST on Youtube carbon nanotubes is viewed more than 5,000 times. The short movie made over 8 months ago explains the research activities of Julie Macpherson's team from an educational viewpoint, focussing on nanoscience and carbon nanotubes. Warwick Chemistry also released a short movie on polymer colloids and supracolloidal chemistry by Stefan Bon's group, which has also proven popular with over 350 views in the last 2 months.

12 Jul 2007

Warwick Chemistry attracts world-class professors

Tim Jones transfers from Imperial and Peter Sadler from Edinburgh to further strengthen Warwick Chemistry's powerhouse. Peter Sadler will be the head of Warwick Chemistry from summer 2007.

prof. Peter Sadler's research is at the interfaces between inorganic chemistry, biology and medicine and is concerned with the design and mechanism of action of novel therapeutic metal complexes.

prof. Tim Jones' research: The ability to control on the nanometre length scale the deposition, structure and functional properties of thin films is a crucial step in the development of a whole range of next generation electronic and optoelectronic devices. Our research deals with the controlled growth of different types of semiconductor materials, both inorganic and organic, with the specific aim of developing new types of nanoscale thin film structures with well-defined properties. We have considerable expertise in a range of sophisticated thin film deposition techniques including molecular beam epitaxy and organic molecular beam deposition, which provide atomic and molecular levels of control over film thickness and property, and the application of scanning probe microscopies. Particular emphasis is placed on correlating thin film property with growth mechanism, the control of surface and interface properties, and the development of prototype device structures for applications as solar cells, light emitting diodes and chemical sensors.

12 Jul 2007

Warwick Chemistry 5th in UK

Warwick Chemistry is number 5 in Guardian 2008 League Table for undergraduate teaching