Chemical Nanoscience
The Northern Carbon Research Laboratories (NCRL) are part of the School of Natural Sciences, specializing in the study of all aspects of carbon science and adsorption. The laboratories have a wide range of state of the art instrumentation for measuring adsorption on porous solids and characterization of materials. In recent years, interests have expanded into studies of a wide range of porous structures including ordered mesoporous and metal organic framework materials.
The potential hydrogen economy has driven investigations of porous metal organic framework materials (MOFs) for hydrogen storage applications. Kinetic trapping effect for hydrogen adsorption on MOFs has been discovered, which is related to framework flexibility and windows and pore cavities in the structure. Comparison of hydrogen and deuterium adsorption measurements was used to validate the measurements and investigate quantum effects in adsorption and desorption.
Techniques for measuring and modelling adsorption kinetics for porous materials have been developed. The remarkable flexibility of certain MOFs was demonstrated by adsorption/desorption of templates that were too large to pass through the windows in the static pore structure, which must open to allow guest adsorption /desorption. The consequence of the presence of pore cavities and windows on the adsorption dynamics has been highlighted in kinetic modelling of diffusion through windows and pore cavities.
A quantum kinetic isotope sieving effect with potential for hydrogen and deuterium separation has been discovered with deuterium adsorption being almost twice as fast as hydrogen. Quantum effects are observed when the difference between pore and adsorbate dimensions is similar to the de Broglie wavelength. The research on the use of porous materials for hydrogen storage is continuing with specific emphasis on improving hydrogen adsorption at temperatures above cryogenic.
The use of MOFs for gas separation using kinetic molecular sieving and hydrogen/deuterium separation using quantum kinetic effects is also expanding. Tailor-made MOFs have potential applications as gas and toxin sensors but their porosity, selectivity and vapour-chromic characteristics must be controlled carefully. This requires the development of new adsorption methods for studying vapours with very low vapour pressures. The field will be further developed with adsorption, spectroscopic, structural and molecular modelling studies.