**2. Applications of nanoparticles**

As the most prevalent morphology of nanomaterials used in consumer products, nanoparticles have an enormous range of potential and actual applications in agriculture, cosmetics, environment, medicine, renewable energies, and petroleum.

There are two pathways for nanoparticles preparation Klaine, *et al.*, [17],


Nanoparticles are classified in a broad spectrum according to their chemical composition, source, size, and morphology [18]. The classification of nanoparticles in the type of material, source, size, composition, and morphology.

Although nanoparticles have always existed in the environment, for example, in volcanic ash and forest fires, they are considered discoveries in the 20th century. Nanotechnology has become popular, and a variety of nanomaterials have been developed and used in various research areas. In addition, the use of nanotechnology in many industrial applications has significantly advanced technical activities. Nanoparticles are widely used in commercial products, such as plastics, cosmetics, ultra-high-resolution displays, medical applications, pharmaceuticals, the environment, etc. The application of nanotechnology and nanoparticle technology has a significant impact on the economic viability of microalgae-based products (such as oils, lipids, bioactive compounds, EPS, and biofuels).
