decondense

Decondense is a verb meaning to cause to become less condensed or to transition from a more compact to a more dispersed state. It is the reverse of condense or condensation, and in many scientific contexts refers to processes that decrease density, loosen packing, or increase molecular freedom. In physical chemistry and thermodynamics, decondensation can describe the opposite of condensation processes, such as vaporization and sublimation, when energy input leads condensed phases to disperse into less dense states. However, the term is less commonly used in formal thermodynamics, where evaporation or sublimation are often preferred.

In biology, decondensation is widely used to describe chromatin decondensation, the process by which tightly packed DNA and histones loosen to form a more accessible chromatin state, allowing transcription, replication, and repair. This decondensation is driven by histone acetylation, ATP-dependent remodelers, and other factors, and is tightly regulated during development and the cell cycle.

In materials science and polymer physics, decondensation can describe the disassembly of condensed aggregates or gels into more dilute forms, or the expansion of collapsed polymer networks upon heating or solvent exposure.

In meteorology and planetary science, decondensation refers to the sublimation or melting of icy condensates as temperature rises, such as frost decondensing back into vapor.

Related terms include condensation, decondensation, decondensed, and chromatin remodeling.