Nanoporous Materials based on Calixarene MOFs for Adsorption Applications

The adsorption of gas molecules onto the surfaces of porous solids is one of the most important operations in the chemical industry. Recently, metal-organic frameworks (MOFs) - a new class of nanoporous materials - have been developed, and these have been shown to have exciting gas adsorption properties. In this joint project with Andrew Burrows (materials chemistry, University of Bath) and Sean Bew (organic chemistry, UEA), we investigated the incorporation of calixarenes, a series of cavity-containing molecules, into MOFs. The potential interactions of gas molecules with both the framework and the calixarene cavities make these materials interesting targets for gas storage and for the separation of mixtures of gases. This project was developed as a vehicle for transferring expertise between the three applicants. Thus Drs. Burrows and Duren learnt organic synthesis techniques with Dr. Bew, Drs. Bew and Duren learnt about MOF synthesis, crystallisation and characterisation from Dr. Burrows, and Drs. Bew and Burrows gained experience of gas adsorption measurements and molecular modelling from Dr. Duren. The collaboration started with this discipline hopping award has developed into a long-term collaboration at the chemistry-chemical engineering interface. The EPSRC funded project "Metal-organic frameworks for catalytic applications" was a follow up from this work / collaboration.

The adsorption of gas molecules onto the surfaces of porous solids is one of the most important operations in the chemical industry. Recently, metal-organic frameworks (MOFs) - a new class of nanoporous materials - have been developed, and these have been shown to have exciting gas adsorption properties. In this joint project with Andrew Burrows (materials chemistry, University of Bath) and Sean Bew (organic chemistry, UEA), we investigated the incorporation of calixarenes, a series of cavity-containing molecules, into MOFs. The potential interactions of gas molecules with both the framework and the calixarene cavities make these materials interesting targets for gas storage and for the separation of mixtures of gases. This project was developed as a vehicle for transferring expertise between the three applicants. Thus Drs. Burrows and Duren learnt organic synthesis techniques with Dr. Bew, Drs. Bew and Duren learnt about MOF synthesis, crystallisation and characterisation from Dr. Burrows, and Drs. Bew and Burrows gained experience of gas adsorption measurements and molecular modelling from Dr. Duren. The collaboration started with this discipline hopping award has developed into a long-term collaboration at the chemistry-chemical engineering interface. The EPSRC funded project "Metal-organic frameworks for catalytic applications" was a follow up from this work / collaboration.

1) We synthesised MOFs that use an upper rim-functionalised calix[4]arene dicarboxylic acid which itself can act as a host for guest molecules. Simulations suggest that such networks are likely to display interesting selectivity to guest molecules.
2) Molecular simulations of MOFs with various pore morphologies revealed that one-dimensional pores with sharp edges are beneficial at low pressure. Yet, because of the limited volume of the energetically preferable corner regions, this effect is much less pronounced at higher pressure.
Have submitted final report