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Caffeine Crystals, Sem
Dr Jeremy Burgess
Photograph - Photograph
Caffeine crystals. Coloured scanning electron micrograph (SEM) of anhydrous caffeine crystals (1,3,7-trimethylxanthine). They were produced by a process called sublimation. A liquid containing caffine, such as coffee, is frozen and heated to 238 degrees Celsius, causing the frozen liquid to vaporise without going through the liquid phase. The vapour is then condensed, which drives the water out and results in anhydrous crystals. Some of the crystals have symmetrically intergrown (upper centre, red and yellow). Caffine stimulates the central nervous system (CNS), increasing alertness and deferring fatigue. It occurs in coffee beans and tea leaves. Magnification x400 at 10 centimetres high.
May 2nd, 2013
Viewed 211 Times - Last Visitor from Coublevie - France on 09/16/2014 at 11:53 AM
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