Materials: Definition, Classification, Properties

Materials chemistry is unique in that it provides the conceptual framework for designing, creating, and understanding new forms of matter, whether organic, inorganic or hybrid. Chemistry is creating a world of new materials as catalysts, sensors, molecular transporters, artificial scaffolds, molecular filters, and light-emitting or electron-conducting ensembles, ranging from nanomaterials and molecular devices to polymers and extended solids, with the potential for broad scientific and societal impact.

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Materials: Definition

It is a somewhat wide concept that must be defined. They are categorised according to their qualities. They have characteristics like hardness, strength, stiffness, thermal conductivity, heat capacity, permeability, magnetism, and so on. 

Materials

“Materials are the fundamental substances utilized in industry to be treated and refined in order to produce additional materials or things. Materials science is the branch of science concerned with the study of materials.” 

Materials may be used in a variety of ways. As a result, they are also categorised depending on their application in industries. Material selection refers to the process of deciding the materials to employ for a certain purpose.

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Materials: Properties

• Materials have a variety of qualities. However, the physical and chemical qualities of matter are taken into account in science.
• Electric, magnetic, thermal, and mechanical qualities are subsets of physical attributes.
• Chemical characteristics of materials include their states, such as solid, liquid, or gaseous, as well as their solubility, pH, reactivity, surface tension, surface energy, corrosion, and so on.
• Elasticity, plasticity, ductility, durability, brittleness, hardness, malleability, resilience, stiffness, viscosity, and other mechanical characteristics of materials are discussed.

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Classification Of Materials

Classification of Materials is done on the basis of their physical properties, as well as their atomic structure and chemical properties. 

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Physical Properties

On the basis of physical properties, materials are classified by appearance, hardness, and transparency. 

Appearance 

• The appearance of materials allows them to be distinguished from one another.
• Some natural materials, such as diamond and gold, are glossy and shiny. 
• Other materials, such as graphite and wood, do not seem glossy and are referred to as non-lustrous. 
• Metals are objects that are shiny in nature, such as iron, gold, and copper.

Hardness

• We notice that while cleaning utensils, the sponge may be squeezed to some amount, but the utensils are often incompressible. 
• Similarly, certain materials, such as chalk, are easily scratched, whilst others, such as aluminium, are not. 
• Easy substances are materials that can be readily squeezed or scratched. 
• Hard substances are materials that are tough to scratch and crush.

Transparency

• You may have played hide-and-seek many times as a youngster. We usually strive to conceal ourselves in this game so that no one can notice us. We often hide behind the backs of things such as sofas and walls. These things are desirable because they cannot be seen through. 
• These are known as opaque things, such as a tree or an iron sheet. 
• Transparent items, on the other hand, are made of a material that allows us to plainly see the objects through them. 
• As an example, consider glass. A transparent object is a material through which things may be seen in part. As an example, consider oily patch paper.

Atomic Structure and Chemical Properties

Materials may be categorized into different categories based on their varied qualities. Metals, ceramics, and polymers are the three types of materials based on their atomic structure and chemical characteristics.

Metals: This class of materials includes metallic elements such as gold, iron, copper, nickel, and aluminum, among others. These materials are rigid, robust, and, for the most part, elastic. Metals such as gold and silver are both ductile and fracture resistant.

Ceramics: This class of substance includes metallic and non-metallic compounds, the majority of which are oxides, nitrides, and carbides. They are reasonably rigid and powerful, yet they are also fragile and prone to fracture.

Polymers: 

• Plastic and rubber are among them. 
• Polyethene, polyvinyl chloride, and nylon are examples of common polymers.
• They lack the stiffness and strength of metals and ceramics. 
• They have a low density. 
• They are exceedingly ductile, which means they may be readily formed into many shapes. 
• Because polymers are malleable, they break down or soften in a hostile environment or at a higher temperature.

Composites: 

• When the two components listed above are combined, the result is a substance known as a composite. 
• The majority of them are man-made, with only a handful occurring naturally.
• Fibreglass is an example of a composite because it is stiff, strong, and ductile.

Semiconductors

• These materials exhibit characteristics that fall between conductors and insulators. 
• Silicon and germanium are two semiconducting crystals.

The following are some of the essential features of materials that are being examined for a certain application.

Elasticity: When the force is eliminated, the material tends to revert to its previous size and shape. Plasticity is the reverse of elasticity in that the material retains its new shape.

Conductivity: The quantity of heat that flows through a substance is defined as its thermal conductivity.

Density: It is defined by the material's mass per cubic centimetre.

Ductility/Malleability: Ductility or malleability refers to a material's ability to alter shape when stretched without deforming.

Also Read: Fossil Fuel

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Raw Materials

• The raw material is unprocessed or minimally processed material that is utilized to manufacture large quantities of goods. 
• It is the most basic form of material that is naturally available. 
• These resources are then used by the industry to create final items and products. 
• These materials are classified as direct and indirect. 
• The raw materials employed in the final product are referred to as direct materials. 
• Indirect materials are utilized in manufacturing but are not present in the finished product. 
• Raw materials include crude oil, iron ore, air, water, mineral, coal, cotton, raw biomass, and so on. 
• Tin, copper, bauxite, iron ore, lead, and other metallic raw minerals are examples.

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Things To Remember

• Materials are fundamental substances utilized in industry to be treated and refined in order to produce additional materials or things. Materials science is the branch of science concerned with the study of materials.”
• Materials have a variety of qualities. However, the physical and chemical qualities of matter are taken into account in science.
• Materials can be classified on the basis of their physical properties: Appearance, Hardness, Transparency
• Metals, ceramics, and polymers are the three types of materials based on their atomic structure and chemical characteristics
• Raw material is unprocessed or minimally processed material that is utilized to manufacture large quantities of goods.

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