Nanoparticles

Question 1

What is surface area to volume ratio?

Answer 1

• The smaller the particle
• The larger the surface area to volume ratio.

Question 2

If you decrease the side of a cube by a scale factor of 10, what happens to the SA to volume ratio?

Answer 2

• The SA: V ratio increases by a scale factor of 10.

Question 3

True or False. Nanosilver has the same properties as normal silver.

Answer 3

• False. They have different properties.

Question 4

How big are nanoparticles?

Answer 4

• They are between 1 and 100nm.

Question 5

What is the size of coarse particles?

Answer 5

• Between 10000nm and 2500nm

Question 6

What is the size of fine particles?

Answer 6

• Between 100nm and 2500nm

Question 7

What is the SA: V ratio for a cube with side length 10nm?

Answer 7

3nm: 5nm =
0.6

Question 8

How is the property of nanoparticles having a large SA: V ratio useful in catalysts?

Answer 8

• More collisisions with reactants
• Less of material needed rather than NORMAL PARTICLES.

Question 9

About how many atoms are in a nanoparticle?

Answer 9

• A few hundred atoms.

Question 10

How are nanoparticles used to deliver drugs into the body?

Answer 10

• Drug trapped in fullerene
• Deliver drugs to correct cells without opening and damaging other cells.

Question 11

What nanoparticles have antibacterial properties and where can they be used?

Answer 11

• Silver nanoparticles
• Deodrants, wound dressings, surgical masks.

Question 12

Why can nanoparticles be used in moisturisers?

Answer 12

• They have properties to make them not oily.
• Good coverage

Question 13

What are nanotubes used for?

Answer 13

• Composites
• Electrical circuits

Question 14

Explain why nanotubes could be used in tennis rackets.

Answer 14

• They have high tensile strength
• Won’t add too much weight.

Question 15

Why are nanoparticles useful in sun cream?

Answer 15

• Better UV protection
• Better coverage

Question 16

What are the 3 main issues with use of nanoparticles?

Answer 16

• May damage cells when absorbed into skin
• If washed away, could damage environment.
• No one knows long - term effects of nanoparticles.

Question 17

Q.)

Some of the public are worried about nanotechnology and potential health concerns. What could the company do to reduce the customers concerns?

Answer 17

• Hire independent scientists to investigate more.
• Label products w/ nanoparticles

Question 18

Q.)

A company wants to put nanocrystal of silver into their socks
a) Give a reason why they would prefer nanocrystals over coarse grains of silver?

Answer 18

• Less needed
• More effective

Question 19

Why are nanoparticles really useful?

Answer 19

• Reduce carbon footprint (less of material needed.)
• New technologies

Question 20

What is the material where nanoparticles are derived from called?

Answer 20

• Called bulk materials.

Question 21

Suggest why some companies that make sun creams might not want to do more tests for nanoparticles.

Answer 21

• Tests = expensive
• Don’t want to damage profits.

Question 22

How big are fine particles?
(Diameter - wise)

Answer 22

Diameters between 100 and 2500nm

Question 23

How big are coarse particles?
(Diamater - wise)
What are they sometimes referred to as?

Answer 23

• Between 2500nm and 10000nm in diameter.
• Sometimes referred to as “dust.”