9.5 Bulk and Surface Properties of Matter Including Nanoparticles
No description yet. This curated deck is ready for daily study.
Card preview (24)
Nanoparticles
Tiny particles containing a few hundred atoms
How big are nanoparticles
1-100nm
Example of nanoparticles
Fullerenes
Surface area to volume ratio formula
Surface area to volume ratio = surface area / volume
Why do nanoparticles have very different properties to normal particles
The is a high surface area to volume ratio means a much greater proportion of their atoms are available to interact with substances
Nanoparticle uses
-Catalysts -Sunscreens -Nanomedicine -Lubricant coatings -Electric circuits for computer chips -Added to plastics in sports equipment -Surgical masks and wound dressings
Why are nanoparticles good catalysts
Reactions take place on the surface of catalysts, so with a big surface area to volume ratio, there will be more collisions and so a faster rate of reaction
Why are nanoparticles used in sunscreens
Provide better protection but don’t leave white marks on the skin
Why are nanoparticles used in nanomedicine
Fullerenes are absorbed more easily to the body than most particles so they could deliver drugs right to the cells their needed.
Why are nanoparticles used in surgical masks and wound dressings
Silver nanoparticles are added to the polymer fibres used to make them, giving antibacterial protection
Dangers of nanoparticles in medicine
Don’t break down easily so they could start to build up in cells
Uses of strong, rigid polymers
Water pipes
Example of a strong, rigid polymer
High density poly(ethene)
Uses of light, stretchy polymers
-Plastic bags -Squeezy bottles
Example of a light, stretchy polymer
Low density poly(ethene)
Uses of poly(styrene) foam
-Packaging to protect breakable things -As a thermal insulator
Uses of heat-resistant polymers
Plastic kettles
Examples of heat-resistant polymers
-Melamine resin -Poly(propene)
Ceramics
A brittle, stiff material made by baking substances
Examples of ceramics
-Clay -Glass
Clay properties
-Soft when dug out of the ground so easy to mould -Can be hardened by firing at high temperatures
Uses of clay
Building material
Why is clay a good building material
It can be hardened at high temperatures and so clay bricks can withstand the weight of lots more bricks on top of them
Glass properties
-Transparent -Strong -Can be moulded when hot -Brittle when thin