Permeabilus

Permeabilus is a conceptual parameter used in transport science to describe the overall propensity of a barrier to permit the passage of substances. It acts as a composite measure that blends aspects of permeability, selectivity, and transport dynamics into a single descriptor.

In practice, permeabilus refers to how readily a material allows solvent and solutes to cross under a given driving force, taking into account pore architecture, solubility, diffusivity, and interactions with the material.

Measurements involve standard diffusion setups such as diffusion cells or chamber assays. By tracking a tracer's flux across the barrier under a known concentration gradient, researchers estimate an effective permeability and, when relevant, a selectivity factor; these can be combined to yield a dimensionless or dimensional permeabilus value depending on the model.

It is used in biomaterials design, tissue engineering, and membranes research to compare transport properties across materials, optimizing for speed of transport, exclusion of harmful species, or controlled release profiles.

Permeabilus is not a universal standard term; definitions vary by discipline and model. It overlaps with but is distinct from intrinsic diffusivity, bulk permeability, and porosity, and it is often treated as a derived quantity rather than a fundamental property.

Etymology reflects roots in Latin permeare and -bilis; the term emerged in modern transport literature as a shorthand for integrated transport characteristics rather than a separate physical constant.