Nanoscience .6

what is nanoscience

Nanoscience is the study of structures that are between 1 and 100 nanometres (nm) in size.

what are most nanoparticles made up of

Most nanoparticles are made up of a few hundred atoms

what is the diameter of Atoms and small molecules

0.1 nm

what is the diameter of nanoparticles

1 to 100 nm

what is the diameter of Fine particles (also called particulate matter - PM_2.5)

100 to 2,500 nm

what is the diameter of coarse particles (PM₁₀, or dust)

2500 to 10,000 nm

what is the diameter of thickness of paper

100,000 nm

what is the SA:V ratio of nanoparticles

Nanoparticles have very large surface area to volume ratios compared to the same material in bulk, as powders, lumps or sheets.

what happens for a slid when there are smaller particles (refer to SA:V ratio)

For a solid, the smaller its particles, the greater the surface area to volume ratio.

what happens to a cube when the length of the side of a cube gets 10 times smaller (refer to SA:V ratio)

If the length of the side of a cube gets 10 times smaller, the surface area to volume ratio gets 10 times bigger.

what A substance that consists of nanoparticles called

nanoparticulate.

what do nanoparticulate materials have that are different from the properties of the same material

Some properties of nanoparticulate materials are different from the properties of the same material in bulk, as powders, lumps or sheets.

what does the properties of nanoparticulate materials being different from the properties of the same material in bulk, as powders, lumps or sheets result to

This difference in properties is the result of two things:

• the tiny size of nanoparticles compared to the same material in bulk

• the large surface area to volume ratios of nanoparticulate materials compared to the same material in bulk

what are some of the uses of Nanoparticulate materials

• medical treatments

• cosmetics, deodorants and sunscreens

• electronics

• catalysts

what does sunscreen do

Sunscreens block harmful ultraviolet light from the sun reaching the skin.

what is used in sunscreen

Zinc oxide blocks ultraviolet light, so is used in sunscreens.

why do many people prefer nanoparticulate zinc oxide to Bulk zinc oxide

• Bulk zinc oxide is white,

• but nanoparticulate zinc oxide is invisible on the skin.

• Many people prefer nanoparticulate sunscreen for this reason.

what does The large surface area to volume ratios of nanoparticulate substances allows them to do

to act as catalysts

Compared to the same substances in bulk, how are nanoparticulate substances being catalysts good

• catalyse reactions more efficiently

• catalyse different reactions that produce different products

what substances have nanoparticulate coatings and how is this efficient

• Self-cleaning window panes have nanoparticulate coatings.

• These catalyse the breakdown of dirt in the presence of sunlight

why are some people concerned about nanoparticles

• Some people are concerned that the small size of nanoparticles makes it possible to breathe them in, or for them to pass into cells.

• Once inside the body, they might catalyse reactions that are harmful.

• Toxic substances could bind to them because of their large surface area to volume ratios, harming health if the nanoparticles do get into the body.

why are nanoparticulate materials a bit dangerous

Modern nanoparticulate materials have only become common recently, so it is difficult for scientists to determine their risks.