porenvolumenlike

Porenvolumenlike is a concept in porous materials science used to describe systems in which changes in porosity are closely coupled to changes in the material’s bulk volume. It refers to a coupled porosity–volume response that occurs under external stimuli such as gas adsorption, pressure, temperature, or chemical triggers, rather than a fixed-porosity framework.

In porous materials exhibiting porenvolumenlike behavior, adsorption-induced deformation is common. Frameworks may swell, contract, or undergo structural transitions that alter accessible pore space in tandem with the overall size and shape of the solid. This coupling can produce breathing-like or swelling phenomena, with measurable effects on adsorption isotherms, selectivity, and mechanical properties. Hysteresis and reversible cycling between distinct structural states are typical features, reflecting the energy exchange between sorption processes and lattice or network flexibility.

Examples of materials where porenvolumenlike behavior has been reported include certain flexible metal–organic frameworks (MOFs) that undergo guest-induced breathing, as well as polymeric porous networks and some covalent organic frameworks. In these systems, conventional models assuming static porosity fail to capture the observed sorption and mechanical responses, necessitating coupled sorption–structure descriptions.

Measurement and modeling of porenvolumenlike materials rely on techniques such as adsorption isotherms, volumetric gas uptake, in situ X-ray or neutron scattering, and diffraction under changing sorption conditions. The term remains a descriptive label rather than a universally standardized category; researchers may instead refer to adsorption-induced deformation, breathing, or volume-change phenomena depending on the context. See also porosity, adsorption, MOFs, and responsive materials.