Some Permeability examples include materials such as paper, cardboard, cotton, wool and sponges; and natural elements such as feathers of birds, wheat, sand and earth.
Permeability is a physical property that allows some materials to be traversed by a fluid, in a limited period of time, and without this implying a change in its molecular structure.
The passage of the fluid through the permeable material depends on three variables: the porosity, the viscosity of the fluid and the pressure of the latter on the surface of the material.
Permeability is not a permanent property; It basically depends on the interaction of the fluid, either a liquid or a gas, with the permeable material.
The 10 main examples of permeable materials
1- Cell membranes
The plant and animal cells are covered by a membrane of selective permeability, which delimits the structure of the cells and the differentiation between the intracellular and extracellular media.
The function of the membrane consists essentially in separating the cytoplasm from the external environment.
It is said to be semipermeable because it allows the absorption and expulsion only of specific substances through this route.
2- Paper
Depending on the thickness and type of the paper, the permeability varies. However, in general terms paper has good permeability.
3- Cardboard
The cardboard is made up of several superimposed layers of paper, each with a different composition and strength.
In turn, each layer of paper is made from virgin and / or recycled pulp. Both materials let fluids pass through each other easily.
4- Lana
It is a natural fiber obtained directly from goats. Given its characteristics, it is widely used in the textile industry for the manufacture of winter clothing.
5- Sponges
Sponges are usually made of plastic polymers and are highly porous utensils, which facilitates the passage of liquids through them.
6- Feathers
Bird feathers are also characterized by allowing fluids to pass through them, depending on the species of bird, the size of the feather and the distance between the fibers that compose it.
7- Cotton
This textile fiber is highly permeable. Due to its properties, it is used as a raw material base for the elaboration of materials for medical use, such as cotton or cotton zigzag motes.
8- Wheat
This cereal is highly permeable. That is why it is important that it be safeguarded under adequate storage conditions, to avoid its deterioration due to the flow of liquid through itself.
9- Arena
Sand is very permeable, especially if the sand is coarse or unconsolidated.
Given its physical and chemical properties, being a very dry material, the sand does not absorb moisture. Therefore, liquids pass through this comfortably.
10- Earth
Similarly, the constitution of the earth makes it possible for the liquid to flow through itself with relative ease.
References
- Medical Dictionary: Permeability. University of Navarra Clinic. Navarra, Spain. Retrieved from: cun.es
- Hernández, R. (2011). Online Botanical Book. University of the Andes. Merida, Venezuela Retrieved from: forest.ula.ve
- Lowery, P. (2017). How to Explain Permeability. Retrieved from: sciencing.com
- Pérez, J., and Gardey, A. (2013). Definition of Permeable. Retrieved from: definicion.de
- Wikipedia, The Free Encyclopedia (2017). Permeability. Retrieved from: en.wikipedia.org