Editing Porous medium (section)

{{Short description|Material containing fluid-filled voids}}
[[File:porousceramic.jpg|thumb|Open-cell ceramic]]

In [[materials science]], a '''porous medium''' or a '''porous material''' is a material containing [[porosity|pores]] (voids).<ref>{{Cite book|title=Hierarchically Structured Porous Materials: From Nanoscience to Catalysis, Separation, Optics, Energy, and Life Science - Wiley Online Library|language=en|doi=10.1002/9783527639588|year = 2011|isbn = 9783527639588|editor1-last=Su|editor1-first=Bao-Lian|editor2-first=Clément|editor2-last=Sanchez|editor3-first=Xiao-Yu|editor3-last=Yang}}</ref> The skeletal portion of the material is often called the "matrix" or "frame". The pores are typically filled with a [[fluid]] ([[liquid]] or [[gas]]). The skeletal material is usually a [[solid]], but structures like [[foam]]s are often also usefully analyzed using concept of porous media.

A porous medium is most often characterised by its [[porosity]]. Other properties of the medium (e.g. [[Permeability (fluid)|permeability]], [[tensile strength]], [[electrical conductivity]], [[tortuosity]]) can sometimes be derived from the respective properties of its constituents (solid matrix and fluid) and the media porosity and pores structure, but such a derivation is usually complex. Even the concept of porosity is only straightforward for a poroelastic medium.

Often both the solid matrix and the pore network (also known as the pore space) are continuous, so as to form two interpenetrating continua such as in a [[sponge]]. However, there is also a concept of closed porosity and [[effective porosity]], i.e. the pore space accessible to flow.

Many natural substances such as [[rock (geology)|rocks]] and [[soil]] (e.g. [[aquifer]]s, [[petroleum reservoir]]s), [[zeolite]]s, [[biological tissue]]s (e.g. bones, wood, [[cork (material)|cork]]), and man made materials such as [[cement]]s and [[ceramic]]s can be considered as porous media. Many of their important properties can only be rationalized by considering them to be porous media.

The concept of porous media is used in many areas of applied science and engineering: [[filtration]], [[mechanics]] ([[acoustics]], [[geomechanics]], [[soil mechanics]], [[rock mechanics]]), [[engineering]] ([[petroleum engineering]], [[bioremediation]], [[construction engineering]]), [[geosciences]] ([[hydrogeology]], [[petroleum geology]], [[geophysics]]), biology and [[biophysics]], [[material science]]. Two important current fields of application for porous materials are energy conversion and [[energy storage]], where porous materials are essential for superpacitors, (photo-)[[catalysis]],<ref>{{Cite journal | doi= 10.1016/j.jcis.2022.12.033 |last1=Madanu|first1=Thomas L.|last2=Mouchet|first2=Sébastien R.|last3=Deparis|first3=Olivier|last4=Liu|first4=Jing|last5=Li|first5=Yu|last6=Su|first6=Bao-Lian|    title = Tuning and transferring slow photons from TiO2 photonic crystals to BiVO4 nanoparticles for unprecedented visible light photocatalysis | journal=Journal of Colloid and Interface Science | volume= 634 | pages = 290–299 |year=2023|pmid=36535165 | url=https://doi.org/10.1016/j.jcis.2022.12.033|url-access=subscription}}</ref> [[fuel cell]]s,<ref>{{Cite book|last1=Zhang|first1=Tao|url=https://doi.org/10.1142/11909|title=Handbook of Porous Materials|last2=Asefa|first2=Tewodros|publisher=WORLD SCIENTIFIC|year=2020|isbn=978-981-12-2322-8|editor-last=Gitis|editor-first=Vitaly|location=Singapore|language=en|doi=10.1142/11909|editor-last2=Rothenberg|editor-first2=Gadi}}</ref> and [[Electric battery|batteries]].