Nanoparticles And Polymers Flashcards
What are nano particles
A nanoparticle is a tiny particle with a size between 1–100 nanometers, containing only a few hundred atoms.
Why are nanoparticles useful
Nanoparticles have a high surface area to volume ratio, which gives them unique properties useful in medicine, electronics, and cosmetics.
Why are nano particles good catalysts
High surface area to volume ratio meaning more collisions can take place
Size of nano particles
Between 1nm and 100nm in diameter
1nm in m
1*10^-9 metres
Sodium chloride has a melting point of 801oC.
Use the structure of sodium chloride to explain why.
The diagram is a diagram using lines to show bonds and circles to show a anions and cations
-> strong electrostatic forces of attraction between ions
-> muse be broken to melt NaCl
Graphite is a good conductor of electricity.
Diamond does not conduct electricity.
Use ideas about structure and bonding in diamond and graphite to explain these observations.
Graphite - has a layered structure, and delocalised lecterns can move through these layers to carry charge
Diamond - no free electrons to carry electrical charge
Why can carbon form many thousands of different compounds?
It is able to bond to itself and make chains and rings
Relationship between boiling points, number of carbon atoms and intermolecular force
LOW boiling point means there’s LESS than 20 carbon atoms and the size of intermolecular forces is SMALL
Inga does the experiment with copper, zinc and dilute sulfuric acid again.
This time she uses a lump of copper rather than copper powder.
Predict, with reasons, the relative rate of reaction.
- The rate of reaction will be less than with just copper powered, but will be faster than other substances.
- This is due to the copper powder having a higher surface area to volume ratio than the lump of copper meaning more collisions take place with the powder
What are thermosoftening polymers
They are plastics which will soften when heated and can be reshaped.
What are thermosetting polymers
Thermosetting plastics are plastics do not soften on heating. They are used when heat resistance is important
Why do thermosetting polymers withstand heat
Thermosetting polymers are fire-resistant because their cross-linked molecular structure prevents melting
What does it mean to be made of cross linked molecules
Cross-linked molecules are polymer chains that are chemically bonded together by strong covalent bonds,
Structural differences between thermosetting and Thermosoftening polymers
Thermos softening - long tangles chains of molecules with weak intermolecular forces between them beaming low energy is needed to break them apart
Thermosetting - strong covalent cress links between molecules which means it takes a high amount of energy to melt
Compare ‘nano’ dimensions to typical dimensions of atoms and molecules:
Nanoparticles range from 1 to 100 nanometres (nm) in size, which is about the same size as large molecules and only a few times bigger than individual atoms (0.1 nm).
Describe the surface area to volume relationship for different-sized particles and describe how this affects properties
As particle size decreases, the surface area to volume ratio increases, making nanoparticles more reactive and giving them unique properties like improved catalysts
Describe how the properties of nanoparticulate materials are related to their uses
Nanoparticles have high reactivity, strength, and unique optical properties, making them useful in
- medicine (drug delivery),
- cosmetics (sunscreens),
- electronics (conductive materials).
Explain the possible risks associated with some nanoparticulate materials
- Nanoparticles can be toxic if inhaled or absorbed, potentially causing lung damage or environmental harm
- their small size makes it difficult to track their long-term effects.
What are the three most common fullerenes of carbon
Buckminsterfullerene (C₆₀) – A spherical molecule made of 60 carbon atoms arranged in a football-like structure.
Carbon nanotubes – Cylindrical fullerenes with high strength and electrical conductivity.
C₇₀ fullerene – Similar to C₆₀ but with 70 carbon atoms, giving it a more elongated shape
What are fullerenes
Fullerenes are carbon allotropes where carbon atoms form hollow structures like spheres or tubes
Differences between fullerines and diamonds
Fullerenes can conduct electricity because they have delocalised electrons within their structure
Diamond does not conduct electricity because all its electrons are held in strong covalent bonds and cannot move freely
Graphite is used to make pencil leads.
Explain why the properties of graphite make it suitable for pencil leads
Graphite has weak intermolecular forces between layers, meaning that they are able to easily slide over eachother and leave marks on the page.
