What does desorb mean?
Desorb is a technical verb meaning to release a substance that has been adsorbed — that is, held as molecules clinging to the surface of a solid or liquid. The word belongs chiefly to chemistry and physics: engineers heat a sample to desorb trapped gases, analysts use temperature-programmed desorption to study how strongly molecules bind to materials, and gas-storage systems rely on controlled desorption cycles to deliver stored fuel. It can be used transitively ('the sample desorbed the hydrogen') or intransitively ('hydrogen desorbed at 200 °C'), though most readers will meet it only in scientific literature. Its opposite is adsorb, and it should not be confused with absorb, which involves uptake through a whole volume rather than release from a surface. Precise, narrow, and indispensable in its field, desorb names a process central to catalysis, filtration, chromatography, and vacuum technology.
verbTo release or drive off a substance that has been adsorbed on a surface or held within a solid material, typically by applying heat or reducing pressure.
- (Chemistry) To release an adsorbed substance from a surface or from within a solid, usually by heating, evacuation, or other changes in conditions.
"The trapped gas begins to desorb once the sample is heated above 100 degrees Celsius."
"The catalyst was flushed with nitrogen to desorb any residual reactants from its surface."
"As the pressure dropped, methane began to desorb from the shale into the wellbore."
Every gas chromatograph and vacuum system depends on this quiet reversal of sticking — heating things up until they let go.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of desorb
Desorb was formed from the Latin prefix de-, indicating reversal or removal, combined with 'sorb', the combining form of Latin sorbere, meaning 'to suck in' or 'to swallow'. It arose as the natural antonym of adsorb within twentieth-century physical chemistry, alongside sibling terms such as absorb and resorb drawn from the same Latin root. English derivatives of sorbere include absorb, resorption, and the noun desorption, which denotes the process itself.
Related word forms
How desorb is actually used
Strictly a technical term used in surface science, catalysis, chromatography, and materials engineering. It is almost always transitive in laboratory usage ('the sample desorbs the gas') but also appears intransitively when the released substance serves as the subject ('the gas desorbed slowly'). Avoid using it for ordinary absorption contexts; it presupposes prior adsorption.
Easily confused with desorb
Adsorb means to collect a substance onto a surface, whereas desorb means to release it back off that surface.
Absorb refers to taking a substance into the bulk of a material throughout its volume, while desorb specifically describes releasing matter that was bound to a surface.