EPSRC Reference: |
EP/C00891X/1 |
Title: |
NEW FRONTIERS IN HIGH PRESSURE ELECTRON PARAMAGNETIC RESONANCE |
Principal Investigator: |
Newton, Professor ME |
Other Investigators: |
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Researcher Co-Investigators: |
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Project Partners: |
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Department: |
Physics |
Organisation: |
University of Warwick |
Scheme: |
Standard Research (Pre-FEC) |
Starts: |
26 September 2005 |
Ends: |
25 March 2010 |
Value (£): |
425,680
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EPSRC Research Topic Classifications: |
Complex fluids & soft solids |
Instrumentation Eng. & Dev. |
Materials Characterisation |
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EPSRC Industrial Sector Classifications: |
No relevance to Underpinning Sectors |
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Related Grants: |
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Panel History: |
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Summary on Grant Application Form |
EPR stands for electron paramagnetic resonance and it is a spectroscopic method employing magnetic fields and microwaves to study materials and molecules with unpaired electrons. It is based on the fact that electrons behave like small magnets and can be flipped in a magnetic field by microwaves. A large number of materials have unpaired electrons, including imperfect solids and free radicals. Imperfect solids can be very useful, for example it is the introduction of impurities in silicon that gives rise to useful electronic properties and silicon chips. Free radicals are formed when bonds in molecules are broken, for example by light radiation, and these radicals can react with and disrupt the processes of living cells. Unpaired electrons play crucial roles in many processes such as photosynthesis, oxidation, catalysis, and polymerization reactions. As a result EPR crosses several disciplines including: chemistry, physics, biology, materials science, medical science and many more. EPR is successful in obtaining structural information, details of electron density distributions, and via the interaction of electrons with nuclei is an element specific probe exquisitely discriminatory to details of the atomic scale environment of the electron. Many of the processes monitored by EPR are sensitive to the environment, for example to the temperature and pressure. Temperature is routinely varied in EPR experiments from -273 degrees Celsius to above 1000 degrees Celsius, but for many interesting studies very high pressures or rapid changes in pressures are required. No easy-to-use high pressure EPR probes with high sensitivity are available. The purpose of this project is to design, build and exploit a new type of high pressure EPR (HP-EPR) instrument. Very high pressures (e.g. 100,000 times atmospheric pressures) can only safely be generated in small volumes because of the risks of catastrophic explosions! Hence the EPR probe needs to be optimised for the study of small samples, and made compatible with high pressure equipment such as a diamond anvil cell. Diamond is the hardest known material, so diamonds make excellent anvils in a high pressure system capable of generating pressures in excess of 100,000 times atmospheres. We propose to use a miniature microwave resonator (called a loop-gap-resonator), integrated with a hybrid high pressure cell which can be configured for use with: (i) diamond anvils (for the highest pressure studies); (ii) hard anvils which allow a sample to be squeezed along a unique axis (uniaxial stress), and (iii) a new cell which allows biological samples to be taken rapidly from atmospheric to moderately high pressures. The driving force to provide the high pressures comes from a material which expands when a voltage is applied and compresses our sample cell (piezoelectric actuator). So rather than using high pressure gases the whole operation of the HP-EPR instrument can be controlled electronically. The construction is a real challenge as the components (e.g. loop-gap-resonators, diamond anvil cells, piezoelectric actuator) have never before been used together in the manufacture of a HP-EPR instrument. The potential of this instrument greatly exceeds anything previously built. Suitable materials must be found to allow safe and reliable operation and we must maintain high sensitivity to the presence of unpaired electrons in the sample. The development of this instrument would have an immediate and profound effect on UK research capability in a number of key areas of science and technology. We propose to study how the shape of proteins changes under pressure and how the shape influences their function, use high pressure to identify the structure of defects which affect the properties of new and technologically useful materials, and investigate by varying the pressure, the physics which will determine if individual unpaired electrons can be used as the building blocks of the computers of tomorrow.
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Key Findings |
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Potential use in non-academic contexts |
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Impacts |
Description |
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Summary |
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Date Materialised |
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Sectors submitted by the Researcher |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Project URL: |
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Further Information: |
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Organisation Website: |
http://www.warwick.ac.uk |