Risks of nanoparticles
- maybe breathed in, absorbed by skill/pass into cells = may be harmful to health
- may take long time to break down once released into the environment
- toxic substances may stick to their substances
- difficult to predict/determine risks
nanoparticle
particle between 1 nm - 10 nm
useful properties of nanoparticles
- large SA:V ratio = new catalysts, self-cleaning windows, ovens
- diff properties to materials in bulk = new paint, cosmetics, medicine
- Fullerenes more easily absorbed into body, so they can deliver drugs straight to cells
what does brittleness/malleability depend on
how easily the particles in the substance can change their positions in the lattice structure
why are metals malleable?
when external force applied - layers of metal ions slide over each other (change shape)
- since bond is between delocalised elec + ions no bonds are broken as the electrons can move
Allotropes
diff forms of an element in the same state
limitations of ball + stick model
- size of atom + length of bond exaggerated
- bonds expressed at physical objects, but they are acc forces
- suggests elements making up the bond don’t move
thermosoftening polymer
polymer chains tangles, but easy to separate = soft, weak, slide over each other
thermosetting polymer
chains joined together by strong covalent bonds = harder, m.p. high
why are some allotropes of carbon able to conduct electricity
They have delocalised electrons as they only form 3 carbon bonds, these electrons can move + carry current
Do fullerenes or graphite have a higher m.p? and why
Graphite does as it has a giant covalent structure
Fullerenes are molecular - so to melt you only break weak intermolecular forces between molecules
why do nanoparticles have diff properties from their bulk material
- greater SA:V ratio = diff qualities, as a greater proportion of their atoms are available to interact w other substances
