It was the first bit of laboratory equipment that we had ever purchased by popping into the car and driving to the local ‘electrical’ shop. Certainly the first piece of equipment we bought from
our own pockets because it was on sale that week and this way was quicker than filling out a purchase order.
We used it immediately we got back into the lab – carrying it between us and probably breaking half a dozen health and safety regulations as we did so.
It already had a plug and so we plugged it in. We tried it immediately (in the fume cupboard of course, we are not that stupid!) and sadly it didn’t work very well. We tried it again and the results weren’t much better. However we persevered and eventually we got a result that showed some potential, but it was clear that we could never trust it with valuable specimens. And so we put it away.
Have you guessed what ‘it’ is yet?
Well, ‘it’ was a microwave oven. We were trying microwave chemistry.
Yes, a microwave oven as bought from your friendly local discount store, a bargain at err whatever it was. And what we were doing was polymerising resin for electron microscopy. Or rather, what we were trying to do was polymerise resin for electron microscopy. The theory was sound, after all getting your specimen into resin and then polymerising the resin was (and is) a time consuming business – usually overnight to infiltrate and another overnight in an electric oven. Microwaves sped things up. Surely anything that saved you hours had to be a good thing? And a microwave oven was just an oven after all?
Except of course it’s not. Microwaves are a very different way of heating as we all began to realise – by trial and error at home as well! That’s why you don’t put metal in them. That’s why they now have revolving stages. That’s why so many early attempts at utilising microwaves for ad hoc scientific endeavour were doomed to failure. And that is why we had areas of unpolymerised resin and that’s why in other places the specimens had – well, cooked.
Like anything else new, it takes some clever thinking and even smarter design to utilise an ‘idea’ in the appropriate manner for different uses. And that goes double for scientific applications. And there are scientific applications aplenty now. Microwave-assisted digestion, microwave-assisted extraction, microwave-assisted organic synthesis – a whole field of microwave chemistry has opened up in the past decades. Microwaving is more efficient, it is greener (uses less solvents and energy) and even has specific (although not yet completely understood) actions that seem – in the case of organic synthesis – to result in purer products. However, to be properly harnessed and used to maximum potential you need the specialised equipment developed by companies like CEM UK. In these different pieces of ‘proper’ scientific equipment microwaves can be focussed to remove hot spots, cooling systems can be introduced, pressurised systems included and multiple vessels added to further increase throughput.
This is what has helped make microwave chemistry such a happening field. And this is why the old microwave oven will never make it out of the storage cupboard.