As the name suggests, nanoparticles are very small size particles. The size of nanoparticles is in the range of 1 -100 nanometers. So any particles below 100 nm in size can be termed nanoparticles. These particles are found to be composed of a few hundred atoms. These small-sized particles of any material possess some distinct properties and qualities that are significantly different from the bulk material. Due to the very small size, the ratio of surface area to volume is much more in the case of a nanoparticle. This feature attributes to some unique optical, chemical, and physical properties. For example, particles of a metal having size less than 50 nm have different performance in terms of ductility as compared to the larger size of the same metal.
Types of Nanoparticles:
Nanoparticles can be of different types depending on their size, texture, and properties. Generally, they are classified into the following groups:
1. Carbon-Based
These nanoparticles are made up of carbon components and are used for strengthening structures as an alternative to steel. Carbon-based nanoparticles include two main materials: carbon nanotubes (CNTs) and fullerenes. The CNT is nothing but a graphene sheet rolled into a tube. These materials are mainly used for structural reinforcement as they are 100 times stronger than steel. CNTs are unique in a way because they are thermally conductive along the length and non-conductive throughout the tube. Fullerenes are allotropes of carbon that have a hollow cage structure of 60 or more carbon atoms. The structure of C-60 is called buckminsterfullerene, and it looks like a hollow football. They have commercial applications due to their electrical conductivity, structure, high strength, and electron affinity.
2. Ceramic-Based
These are made up of oxides, carbonates, and phosphates. They show good resistance to chemicals and heat. By controlling certain characteristics of ceramic nanoparticles such as size, surface area, porosity, surface-to-volume ratio, etc., they exhibit a good drug delivery agent. These nanoparticles have been effectively used as drug delivery systems for many diseases such as bacterial infections, glaucoma, cancer, etc.
3. Metal-Based
These nanoparticles are prepared from metals using chemical and electromechanical processes. These nanoparticles have applications in research fields, detection and imaging of biomolecules, and environmental and bioanalytical applications. For example in SEM gold nanoparticles are used to coat the sample before analysis. This is usually done to enhance the electronic stream, which helps us to get high-quality images.
4. Semiconductor-Based
These nanoparticles have properties similar to many metals and non-metals. Its usages are in photocatalysis, electronics devices, photo-optics, and water splitting.
5. Polymer-Based
These are particles obtained from organic materials. They have applications in drug delivery and diagnostics. Drug delivery with polymeric nanoparticles is highly biodegradable.
Use of Nanoparticles:
Nanoparticles can contribute special qualities to the materials prepared from them. These can be used in a particular way to prepare products that are suitable for a specific purpose. The materials prepared using nanoparticles are called nanomaterials. Nanomaterials have wide applications in a variety of sectors including industries, healthcare, consumer products, transport, and environmental purification. Some of the major applications of nanoparticles are explained as follows:
- Nanoparticles have played a very important role in biomedical applications which are called nanotherapeutics. This ensures clinical applications for chemotherapy drugs to cancerous growths and drug delivery to damaged arteries with improved efficacy. The improved drug delivery and targeted therapy in the body parts help in some of the treatments that become possible only because of nanoparticles. It has important applications in gene delivery, biomarker mapping, and molecular imaging. It also helps in the detection and diagnosis of diseases caused by biological agents.
- In the cosmetics industry, nanoparticles of certain minerals are used to prepare sunscreen products to provide long-term UV protection. They also have been put to use in making deodorants.
- The properties of nanoparticles have been effectively utilized to make a composite material that is used to manufacture the modern rubber tire of vehicles. Its material is a composition of rubber and inorganic filler made by nanoparticles that reinforces the structure. The material is stronger, durable, and demonstrates better grip quality on the road surface.
- Nanoparticles have found applications in the production of crack-resistant paints, dust-free coatings for walls, scratchproof sunglasses, stain-resistant fabrics, etc. Nanomaterials are also used to manufacture various household products such as dirt removers, degreasers, aerosol sprays, and air purifiers.
- The sports industry products are also being made using nanoparticles to improve performance by providing qualities like lightweight, durability, and damage resistance.
Production of Nanoparticles:
Naturally occurring nanoparticles include oxides and carbonates that are generated in large quantities during the combustion of diesel fuel. They are also produced during volcanic eruptions and forest fires. Nanoparticles can be made synthetically which plays a significant role in various fields. With the development of nanotechnology, a range of nanoparticles is produced synthetically as per the required shape and dimensions ranging between 1 and 100 nanometers. The objective is to obtain components with specific surface characteristics and chemical compositions.
They are distinct in their properties and can be used effectively to serve diverse purposes. These properties can contribute to stronger, lighter, cleaner systems and products widely used in industrial, medical, and domestic sectors. The size and surface characteristics of nanoparticles can be manipulated which makes it easier to apply in various ways to achieve desired results.
Important Data on Nanoparticles:
- Silver nanoparticles are used in making medical equipment, textiles, and cosmetics taking advantage of their antifungal and antibacterial properties.
- 3-D printers emit nanoparticles that may be harmful to sensitive people with higher concentrations that are dependent on the types of filaments used in the printing process.
Conclusion:
Study and research on nanoparticles are gathering momentum in the field of science and technology. Nanotechnology deals with the study and application of extremely small things across different fields of science such as physics, chemistry, biology, metallurgy, and engineering. The development in nanotechnology has opened up new ways of using nanoparticles in various fields. The nanoparticles have demonstrated their efficacy and benefits in biomedical, mechanical, and electronic fields. The specific and unique properties of these particles are used scientifically to achieve results that facilitate important advancements in various sectors.