Nanoparticle & Microparticle Synthesis

Nanoparticles and microparticles represent a unique class of materials with vast technological potential in fields such as energy, imaging, medicine, and environmental applications. Nanoparticles are defined as having at least one physical dimension smaller than 100 nanometers, while microparticles range from approximately 1 to 1000 micrometers in size. Despite sharing the same composition as their bulk counterparts, these particles exhibit exceptional optical, electrical, thermal, and magnetic properties due to their small size. Researchers have developed advanced synthesis methods to precisely control the properties, shape, composition, and size distribution of these particles, tailoring them for specific applications. The synthesis of nanoparticles and microparticles can be categorized into physical, chemical, and biological techniques, utilizing both bottom-up and top-down approaches. In physical methods, particles are created by reducing the size of source materials through top-down processes like milling, gas condensation, electro-spraying, lithography, and thermal decomposition. In contrast, chemical methods involve nucleating and growing particles from atomic or molecular precursors, typically in the liquid or vapor phase, in a bottom-up fashion. These chemical processes include microemulsion, hydrothermal, microfluidic, chemical vapor deposition, pyrolysis, and sol-gel techniques. Chemical synthesis allows for the production of nanostructures with fewer defects, more complex and homogeneous compositions, and scalable, cost-effective production. However, as many of these techniques can be labor-intensive and produce toxic byproducts, biological or 'green' methods have emerged, such as biogenesis using microorganisms and plant extracts. These eco-friendly methods offer a sustainable approach to producing non-toxic particles suitable for biomedical and environmental applications.