I am a Tutorial Fellow in Inorganic Chemistry at Trinity College and a Professor of Inorganic Chemistry in the Department of Chemistry, University of Oxford. I have a BSc and PhD (2001) both from Imperial College London. My PhD studies were supervised by Professors Vernon Gibson FRS and Nick Long and I developed new homogeneous catalysts for olefin polymerization. I was a postdoctoral researcher at the University of Minnesota (2001-02) working with Professors Bill Tolman and Marc Hillmyer on lactide polymerization catalysis. Following this I moved to Cambridge University (2002-03) to work with Professors Andrew Holmes FRS and Richard Friend FRS on organometallic conjugated polymers for light emitting devices. In 2003, I was appointed to the academic staff at Imperial College London as firstly a lecturer (2003), EPSRC Advanced Research Fellow (2005-11), Senior Lecturer (2007), Reader (2009) and Professor of Polymer Chemistry and Catalysis (2012). I moved from Imperial College to Oxford in 2016.
I tutor all areas of Inorganic Chemistry. I also have a large, multi-disciplinary research group in the Department of Chemistry where I supervise students for part II (fourth year UG) research projects and DPhil students. My research team currently comprises 6 postdoctoral researchers and 10 DPhil students.
My research involves making and studying new catalysts and materials, often polymers, for applications such as plastics, elastomers, electronics, medicine and catalysis. My research in polymerization catalysis involves the preparation and study of new metal complexes as homogeneous polymerization catalysis. I am particularly interested in using renewable resources and catalysis to make polyesters, polycarbonates, polyethers and other oxygenated copolymers.
An exciting recent discovery is a series of catalysts that allow carbon dioxide to be used as a raw material to make polymers. The catalysts are efficient under low pressures of carbon dioxide and allow 30-50% of the mass of the polymer to be sustainably sourced. It is even possible to use waste carbon dioxide emissions to make the polymers. The materials may be used as elastomers, adhesives, sealants, coatings and insulation foams. I formed the company econic technologies (http://www.econic-technologies.com/) which has commercialized these catalysts and the technology. Econic technologies is based in London and Manchester and has raised >£13M in funding from various industrial and venture funders.
Another research area concerns the use of plants as raw materials to make oxygenated polymers. Polylactide is a commercial polymer which is sourced from starch, which may be harvested from corn/sugar. I have developed various catalysts that allow polylactide to be produced efficiently and with high control. Understanding how to improve the stereochemical control during catalysis is an important means by which to regulate and improve the thermal/mechanical properties of the material. Research in my team also addresses how to use other carbohydrates, including glucose, as monomers to make degradable polymers suitable for medical applications (in collaboration with Molly Stevens, Imperial College London).
Very recently, I have discovered a new ‘switchable’ catalysis which allows mixtures of monomers to be efficiently transformed into block sequence controlled copolymers. The catalysts are able to link together various distinct polymerization cycles and can be used to deliver multi-block copolymer efficiently. The copolymers produced using this new method show properties suitable for application as elastomers or rigid plastics. We are currently studying in detail the self-assembly and applications for these block copolymers. In collaboration with Alexander Bismarck (university of Vienna) we have investigated the preparation and properties of various composites which comprise renewable polymers and cellulose as the structural directing agent.
My research in nanoparticles includes developing new means to make, characterize and applying them in polymer composites, as catalysts or in electronics. This area of research is carried out in collaboration with Prof. Milo Shaffer (Dept. Chemistry, Imperial College London). We have developed various organometallic methods to prepare ZnO and doped ZnO nanoparticles – the synthesis operates in organic solvents and at room temperature and allows the preparation of small (3-4 nm) particles with high crystallinity and surface coordinated ligands. The nanoparticles have been used as fillers in various polymer composites for both commodity and electronic applications. We have also led a multi-disciplinary project investigating the application of colloidal nanoparticles of ZnO, Cu and other metals as catalysts for carbon dioxide reduction to methanol. The application of colloidal nanoparticles, both metals and metal oxides to various gas to liquids transformations, particularly as relevant for the production of fuels is an on-going research interest.
Overall, my research areas include preparing, characterizing and applying polymers and materials for a range of uses. I have enjoyed a range of different industrial collaborations and am motivated by applied research challenges. I also have a network of academic collaborators and am interested in fundamental problems related to catalysis, kinetics and polymer chemistry.
1. Pike S, White E, Shaffer M, Williams CK, Simple Phosphinate Ligands Access New Zinc Clusters Identified in the Synthesis of Zinc Oxide Nanoparticles, Nature Communications, 2016.
2. Romain, C.; Zhu, Y.; Dingwall, P.; Paul, S.; Rzepa, H. S.; Buchard, A.; Williams, C. K., Chemoselective Polymerizations from Mixtures of Epoxide, Lactone, Anhydride, and Carbon Dioxide. J. Am. Chem. Soc. 2016, 138 (12), 4120-4131.
3. Thevenon, A.; Romain, C.; Bennington, M. S.; White, A. J. P.; Davidson, H. J.; Brooker, S.; Williams, C. K., Dizinc Lactide Polymerization Catalysts: Hyperactivity by Control of Ligand Conformation and Metallic Cooperativity. Angew. Chem. Int. Ed. 2016, 55 (30), 8680-8685.
4. Zhu, Y.; Romain, C.; Williams, C. K., Selective Polymerization Catalysis: Controlling the Metal Chain End Group to Prepare Block Copolyesters. J. Am. Chem. Soc. 2015, 137 (38), 12179-12182.
5. Garden, J. A.; Saini, P. K.; Williams, C. K., Greater than the Sum of Its Parts: A Heterodinuclear Polymerization Catalyst. J. Am. Chem. Soc. 2015, 137 (48), 15078-15081.
6. Chapman, A. M.; Keyworth, C.; Kember, M. R.; Lennox, A. J. J.; Williams, C. K., Adding Value to Power Station Captured CO2: Tolerant Zn and Mg Homogeneous Catalysts for Polycarbonate Polyol Production. ACS Catalysis 2015, 5 (3), 1581-1588.
7. Bakewell, C.; White, A. J. P.; Long, N. J.; Williams, C. K., Metal-Size Influence in Iso-Selective Lactide Polymerization. Angew. Chem. Int. Ed. 2014, 9226 –9230.