What are Nanoparticles?
Nanoparticles are particles that have at least one dimension less than 100 nanometers. Due to their extremely small size, they exhibit unique physical and chemical properties compared to their bulk counterparts. These properties are harnessed in various fields, such as medicine, electronics, and environmental science.
Polymeric Nanoparticles
Polymeric nanoparticles are made from natural or synthetic polymers. They are highly versatile and are used in
drug delivery,
gene therapy, and
biomedical imaging. Their biocompatibility and ability to encapsulate therapeutic agents make them ideal for medical applications.
Semiconductor Nanoparticles
Semiconductor nanoparticles, also known as
quantum dots, have unique optical and electronic properties. They are used in
solar cells,
LEDs, and
biological imaging. Their size-tunable light emission makes them particularly valuable in optoelectronics and medical diagnostics.
Properties of Nanoparticles
The properties of nanoparticles can be broadly categorized into physical, chemical, and biological properties. These properties are influenced by factors such as size, shape, surface area, and chemical composition. Some of the notable properties include: High Surface Area: Nanoparticles have a high surface area to volume ratio, which enhances their reactivity and catalytic efficiency.
Quantum Effects: At the nanoscale, quantum mechanical effects become significant, affecting the electronic and optical properties of nanoparticles.
Surface Plasmon Resonance: Metal nanoparticles exhibit surface plasmon resonance, which is the collective oscillation of electrons in response to light, leading to unique optical properties.
Synthesis of Nanoparticles
Nanoparticles can be synthesized using various methods, broadly classified into
top-down and
bottom-up approaches. In top-down approaches, bulk materials are broken down into nanoparticles using techniques such as
milling and
lithography. Bottom-up approaches involve the assembly of nanoparticles from atomic or molecular precursors using methods like
chemical vapor deposition and
sol-gel synthesis.
Applications of Nanoparticles
The unique properties of nanoparticles make them suitable for a wide range of applications:
