English

Noun

1. A closed glass vessel containing a desiccant (such as silica gel) used in laboratories for drying materials or for keeping them dry

Derived terms

• vacuum desiccator

Desiccators are sealable enclosures containing desiccants used for preserving moisture-sensitive items. A common use for desiccators are to protect hygroscopic chemicals from humidity.

The contents of desiccators are exposed to atmospheric moisture whenever the desiccators are opened. It also requires some time to achieve a low humidity. Hence they are not appropriate for storing chemicals which react quickly or violently with atmospheric moisture. A glovebox or Schlenk-type apparatus may be more suitable for these purposes.

Laboratory use

In laboratory use, the most common desiccators are circular, and made of heavy glass. There is usually a removable platform on which the items to be stored are placed. The desiccant, usually an otherwise-inert solid such as silica gel, fills the space under the platform.

A stopcock may be included to permit the desiccator to be evacuated. Such models are usually known as vacuum desiccators. When a vacuum is to be applied, it is a common practice to criss-cross the vacuum desiccator with tape, or to place it behind a screen to minimize damage or injury caused by an implosion.

To maintain a good seal, vacuum grease is usually applied to the flanges.

See also

• desiccation