Several methods are employed to purify nanomaterials, each with its own advantages and limitations:
Centrifugation: This method uses centrifugal force to separate nanoparticles based on their size and density. It is often used for purifying metallic and semiconductor nanoparticles. Filtration: This technique involves passing the nanoparticle solution through a porous membrane to remove larger particles and aggregates. Filtration is commonly used for purifying carbon nanotubes and other elongated nanostructures. Chromatography: Various forms of chromatography, such as size-exclusion and high-performance liquid chromatography (HPLC), are employed to separate nanoparticles based on their size, charge, or chemical properties. Electrophoresis: This method uses an electric field to separate charged nanoparticles based on their size and charge. It is often used for purifying DNA-functionalized nanoparticles and other bio-nanomaterials.
