Statistical Mechanics & Thermodynamics Group

Statistical mechanics and thermodynamics form an essential link between the properties of molecules and the behaviour of macroscopic matter. Statistical mechanics can provide an exact synthesis of microscopic length and time scales (<10^-8 m, 10^-9 s) through the mesoscopic or colloidal domain (10^-4- 10^-8 m, 10^-4  - 10^-9 s) to the everyday world (>10^-4 m, 10^-4 s). This theoretical science is directly relevant to the development of a wide range of 21st century technologies under titles such as molecular engineering, smart materials and nano technology. 

The last decade has witnessed revolutionary advances in both the theoretical understanding of molecular systems (statistical mechanics coupled with computer simulation) and in the development of sophisticated experimental tools (scanning probe microscopes, surface plasmon resonance, evanescent wave ellipsometry, second harmonic generation, sum frequency generation, x-ray, neutrons). 

A key aspect of all this work is that it is very much an interdisciplinary enterprise, embracing synthetic chemistry, physical chemistry, physics, polymer science, biology, food science, materials and engineering. In all of this, the only route to a predictive science linking the properties of molecules with the behaviour of the finished product is that based on statistical mechanics.

Recent ‘Hot Topics’

• Contributions of chemistry to the growth area of nanotechnology: self assembly in solution (new mesoscale structures, liquid crystals, fluid membranes), surface active polymers and structure property relationships, molecular ordering at interfaces and the control of colloidal interactions.       

• New computer simulation technologies based on advanced statistical mechanical theory (density functional theory) using ab initio intermolecular and ionic potentials, applied to problems such as chemical reactions in clusters and catalysis in porous systems. For example, current ‘de novo’ design of zeolite catalysts by computer modelling.       

• Use of mesoscale simulation techniques (dissipative particle dynamics, cellular automata and lattice Boltzmann) to study the rheology of detergents and colloids, and the kinetics of phase separation. When coupled with statistical mechanics, these allow for the rigorous treatment of whole systems, spanning different regimes of length and time scales. The chemical industry is already active in developing and using these methods.       

• Recent advances that underpin chemical engineering: the thermodynamics of associated fluids and the effect of association on liquid-liquid, liquid-vapour and liquid crystal phase behaviour. For example, self-assembly via hydrogen bonding and chain and ring forming molecular fluids.       

• Statistical mechanics applied to biological sciences: protein and RNA folding, assembly of microtubules and ion channels, the physical properties of cell membranes, budding of vesicles, molecular evolution on rugged fitness landscapes, neural net modelling of brain function, and molecular motors.