Introduction
According to ISO Technical Standard, a nanoparticle is defined a nano-object with all three external dimensions in the nanoscale, whose longest and the shortest axes do not differ significantly, having size between 1 and 100 nanometres (nm). Nanopowders are agglomerates of particles, nanoparticles, or nanoclusters. In contrast to nanopowders which tend to agglomerate to larger grains and where electron microscopy shows large particle sizes with a relatively broad size distribution, nanoparticles generally exhibit small sizes, well defined and regular shapes and have histograms with a narrow size distribution curve.
Fig 1 Nanoparticles
Nanoparticles and nanopowders are of great scientific interest as they are, in effect, a bridge between bulk materials and atomic or molecular structures. The tiny size of nanoparticles gives them an extremely high surface area to volume ratio that results in extraordinary properties like large surface area, mechanically strong, optically active and chemically reactive, which make nanoparticles unique and suitable applicants for various applications.
Applications
Applications in drugs and medications: Nanoparticles have drawn increasing interest from every branch of medicine for their ability to deliver drugs in the optimum dosage range often resulting in increased therapeutic efficiency of the drugs, weakened side effects and improved patient compliance.
Applications in manufacturing and materials: Nanoparticles manufacture provide very interesting substances for material industry. Metals nanoparticles with the unique plasmon absorbance features have been exploited chemical sensors and biosensors.
Applications in electronics: Unique structural, optical and electrical properties of nanoparticles makes them as the key structural blocks for new generation of electronic, sensors and photonic materials.
Applications in mechanical industries: Nanoparticles can offer many applications in mechanical industries especially in coating, lubricants and adhesive. Tribological properties can be applied for embedding nanoparticles in the metal and polymer matrix to increasetheir mechanical strengths.
Applications in the environment: Due to high surface to mass ratio natural nanoparticles play an important role in the solid/water partitioning of contaminants, forming coprecipitate by adsorbing the contaminants to their surface.
