Nanoparticles and Surface Area to Volume Ratio

Surface Area to Volume Ratio of Nanoparticles

• The surface area to volume ratio of a material is significantly affected when it is composed of nanoparticles.
• Materials made up of nanoparticles have a relatively larger surface area compared to the same volume of material made up of bigger particles.

Mathematical Representation

• The surface area of a sphere is 4πr2, where r is the radius.
• The volume of a sphere is (4/3)πr3.
• The surface area to volume ratio is 3/r, indicating that the ratio increases as the radius of the sphere decreases.

Properties of Nanoparticles

• When a given volume of material is made up of smaller particles, the surface area of the material increases.
• A greater proportion of particles are found at the surface of the material as particle size decreases.
• Materials made of nanoparticles have a much greater surface area per unit volume ratio compared to materials made up of bigger particles.

Chemical Reactivity

• Nanoparticles are more chemically reactive due to their increased surface area.
• Chemical reactions occur between particles that are on the surface, making a given mass of nanomaterial more reactive than the same mass of material made up of large particles.
• Materials that are inert in their bulk form can become reactive when produced in their nanoparticle form.