Research Fellows Directory
Dr Timothy Easun
My research targets the use of photochemistry to control molecular flow in microporous materials in order to make functional nanofluidic devices. This involves the functionalisation of crystalline porous materials, specifically using thermally and photochemically active components to control framework properties and direct guest uptake and release. Nanofluidics is the flow of gases and liquids through very small channels, only a few nanometres across. There are many important applications that arise from this, so understanding and controlling this flow is a rapidly growing area of interest, especially as gas/liquid flow on the nano-scale can behave in unexpected ways. Being able to study and control the movement of molecules on this scale offers exciting possibilities in the miniaturising of microfluidic devices used for medical diagnostics, sensing, and materials sorting applications. Current state-of-the-art microfluidic and nanofluidic devices are used for DNA fragment sizing, protein expression analyses, mass-limited sample handling and nano-optofluidics. Metal-organic frameworks (MOFs) are highly ordered porous materials with extremely well-defined pores and channels that offer a new platform for nanofluidic studies. MOFs have already found applications as gas-storage media, but their use for studying nano-scale fluid flow is new.
The key concepts that underpin this research are those of supramolecular photochemistry, nanofluidics, time-resolved spectroscopies, photocrystallography and microporous materials with nanoscale pores and channels. The work is focussed on two main areas: the surface modification of metal-organic framework (MOF) crystals to photogate access to and from their pores and the design of new MOF linkers that change shape on photoirradiation. These projects require the design, synthesis and characterisation of photoactive molecules, studied by ultrafast time-resolved and spatially-resolved spectroscopies, coupled with new and emerging photocrystallographic techniques that allow us to understand in detail the behaviour of these molecules in single crystals.
Interests and expertise (Subject groups)