Freeze-drying, called lyophilisation, is a conservative method to dry sensitive material, like biological samples, polymers or certain nanoparticles, without changing most of their porperties.
The water in a frozen sample is removed by sublimation in vacuum. At a partial pressure of 6.11 mbar ice becomes vapor without turnig to water first. The condesor has a considerably lower temperature than the sample, which is why the emitted water steam from the samples condenses there and dows not redeposit on the sample.
The setup consists of a drying chamber for drying of aqueous samples with a capacity of 4kg and a drying efficiency of 4kg / 24h. Drying is done at temperatures down to -55°C.
Our setup contains three layers with a diamater of 250 mm and an interlayer distance of 79 mm, resulting in a total area of 0.15 m². Additionally there are 12 connections to dry samples in round-bottom flasks.