nonporeuze

Nonporeuze is a term used in materials science to describe materials or surfaces that exhibit negligible porosity, meaning they lack an interconnected network of pores that would permit fluid flow under normal conditions. It is used to distinguish dense, nonporous materials from porous, microporous, mesoporous, and macroporous classes. In practice, a material is regarded as nonporeuze when porosity is effectively zero within the limits of measurement sensitivity, and its permeability to gases and liquids is extremely low.

Porosity and related properties are central to the concept. Porosity is the fraction of a material’s volume that can be occupied by voids, but a nonporeuze material has no accessible void network contributing to transport. Closed porosity may exist in some materials, but it does not connect to the surface to allow fluid movement. Permeability, tortuosity, and pore connectivity are used to assess how close a material is to nonporeuze behavior.

Achieving nonporeuze microstructures typically involves dense processing: high-temperature sintering and/or hot pressing for ceramics and metals, or casting and annealing for glasses and polymers to eliminate voids. Properties associated with nonporosity include low gas and liquid diffusivity, high mechanical density, and often high chemical resistance.

Measurement and characterization rely on density and permeability tests. Skeletal density measurements (for example, helium pycnometry) assess closed porosity, while gas permeability or diffusion tests evaluate access to any potential pore network. Techniques such as mercury intrusion porosimetry and adsorption isotherms help confirm the absence of open porosity.

In applications, nonporeuze materials serve as diffusion barriers, seals, protective coatings, optical and electronic encapsulations, and components where minimal fluid transport is required. Real-world materials approach nonporeuze behavior but may retain trace porosity due to processing limitations.