The materials are (substances natural or artificial ) that are used to build other things. Each industry uses specific materials. For example, for the construction industry metals, cement, and ceramics, among others, are used as materials, while cotton, wool, and synthetic fabrics are used in the textile industry.
For example, if we want to know why oil forms a layer on the surface of the water, we will be interested in two properties: solubility and density. Other properties such as toughness, color, odor, or conduction of electricity will be less important.
What are some common properties of materials?
The properties can be:
- Density: The amount of mass in a given volume
- Physical state: It can be solid, liquid, or gaseous.
- Organoleptic properties: Color, smell, taste
- Boiling point: The maximum temperature that a substance can reach in a liquid state. Above that temperature, it goes into a gaseous state.
- Melting point: The maximum temperature at which a substance is in a solid-state. Above that temperature it becomes liquid.
- Solubility: The ability of one substance to dissolve in another
- Hardness: The resistance of a material to perforations.
- Electrical conductivity: The ability of a material to conduct electricity.
- Flexibility : The ability of a material to bend without breaking. Its opposite is stiffness.
- Opacity: The ability to prevent the passage of light. Its opposite is translucency.
Examples of materials and their properties
- Oakwood: Hard and heavy wood, because its density is between 0,760 and 0,991 kg / m3. Due to its chemical characteristics, it is very resistant to rot. Due to its organoleptic conditions (aroma) it is used for wine barrels, transferring its characteristics to the final product.
- Glass: It is a hard material (it is very difficult to drill or scratch), with a very high melting temperature (1723 degrees), so it is not affected by temperature changes. So it can be used in various industries, from construction (windows) to tableware. Pigments that change it’s color (organoleptic properties) and layers that make it opaque can be added to the glass, preventing the passage of light. It is relatively insulating from noise, temperature and has low electrical conductivity.
- Fiberglass: Artificial material produced from silicon dioxide filaments. It is a good thermal insulator, but it is not chemical resistant. It is also a good acoustic and electrical insulator. Due to its flexibility, it is used in tent structures, high resistance fabrics, pole vaulting poles.
- Aluminum: In thin layers, it is a metal that is not only flexible but also soft, that is, it is extremely malleable. In thick layers it becomes stiff. So aluminum can be used in flexible packaging (even in so-called “aluminum foil”) but also in large rigid structures of all sizes, from food cans to airplanes.
- Cement: Mixture of calcined and ground limestone and clay. It hardens on contact with water. It is resistant to chemicals and high temperatures. Its resistance, however, decreases over time because of its porosity increases.
- Gold: It is a soft and heavy metal. Due to its high resistance to corrosion, it is used in industry and electronics. It is known for its organoleptic characteristics (its brightness and color) for which it is even confused with other metals of lower economic value. It has a density of 19,300 kg / m3. Its melting point is 1,064 degrees.
- Cotton fiber: It is one of the materials used in the textile industry. Its color ranges from white to yellowish-white. The fiber diameter is very small, between 15 and 25 micrometers, which makes it very soft to the touch, making it highly appreciated in the industry.
- Lycra or elastane: It is a polyurethane fabric. It has great elasticity, being able to be stretched up to 5 times its size without breaking. Also, it returns to its original shape quickly. It does not retain water between the fibers of its fabrics, so it dries quickly.
- PET (polyethylene terephthalate) : It is a thermoplastic of high rigidity, hardness, and resistance. It is very resistant to chemical and atmospheric agents (heat, humidity), which is why it is used in beverage, juice and medicine containers.
- Porcelain: It is a ceramic material that is characterized by being compact and translucent, in which it differs from all other ceramics. It is rigid but fragile and of low elasticity. However, it is very resistant to chemicals and high temperatures.