Microreactors are miniaturised chemical plants, where fluids are pumped through channels only micrometres across into equally tiny reaction chambers. Devoid of turbulence and using only small quantities of chemicals, they are proving useful for testing new reaction routes for the process industries and for screening chemical compounds for toxicity or pharmaceutical activity.
Researchers from Liverpool,
Although environmental friendliness is a major advantage, the methods of making them are anything but green. Microreactor design is based on the circuitry of microprocessors and similar techniques are used to make them; corrosive chemicals are used to etch the channels from blocks of metal or alloy. The project, due to begin in October, uses rapid prototyping techniques, making the reactors by building material up rather than taking them away.
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The microreactors will be passed to project leader Pawel Plucinski at
The functionalised surfaces will be further converted to make them catalytically active, by coating them with polymers with catalytic activity. ‘There are coated micro-reactors now, but they are designed for gas-phase experiments; they are coated using vapour deposition and work at very high temperatures. We want to do liquid-phase work, so we need the mixing function as before and we can use polymer catalysts because the reaction temperatures are so much lower,’ Plucinski said.
To test the devices, chemical engineers are developing new sensors. ‘We need to have IR and UV to tell what’s going on, and we’re looking at piezoelectric devices we can install in the channels for information about the flow rates,’ Plucinski said. ‘Existing sensors only work on single-channel devices.’