Carbon allotropes and nanoparticles Flashcards
what is an allotrope?
atoms bonded to each other in specific different ways resulting in different properties
structure of diamond
- carbon allotrope
- each carbon is covalently bonded to four other carbons in a tetrahedral
- covalent network substance arranged in a 3D lattice
properties of diamond
hard, brittle, doesn’t conduct electricity, high melting/boiling point, insoluble
uses of diamond
jewellery, cutting tools
structure of graphite
- in a covalent layer lattice strucutre
- each carbon is covalently bonded to 3 other carbon atoms
- there is one delocalised electron per carbon
- weak dispersion forces exist between layers
properties of graphite
high melting and boiling point, soft, slippery, conducts electricity
uses of graphite
pencils, electrodes, lubricants
structure of fullerenes
- hollow cage like structure
- carbons are arranged in pentagons and hexagons
structure of buckyballs
- fullerene
- arranged in a hollow sphere
properties of buckyballs
soft, low melting pont, not a covalent network, insoluble
uses of buckyballs
in medicine (carry drugs in the body), in solar panels
strucuture of graphene
- like a single layer of graphite
- strong covalent bonds
- with no weak intermolecular forces
properties of graphene
extremely strong, conduct electricity (super conductivity)
uses of graphene
- improve energy capacity and cahrge rate in rechargeable batteries
- bulletproof armour
- photovoltaic cells
structure of nanotubes
- fullerene
- sheet of graphene rolled into a hollow tube with a diameter of 1nm
properties of nanotubes
thermal and electrical conductivity, hard, lightweight
uses of nanotubes
nanotechnology, electronics
what are nanomaterials
materials of which a simple unit is sized between 1-100 nanometres (10^-9m)
- properties may differ from bulk material
what is an example of how properties of nanomaterials may differ from the bulk material
optical properties
- bulk form of gold is yellow metal
- gold nanoparticles can take on a range of colours
- bulk ZnO (for sunscreen) is white, but the nanoparticles are clear
what are the uses of nanoparticles
- very small, letting them into biological material
- can be mixed with materials to form composite materials with better properties
- used in catalysts to increase the rate of catalytic reactions and boost chemical reactions
- increase strength and durability of materials
health benefits of nanotech/nanoparticles
- Nanoparticles from buckyballs could trap tiny amounts of substances inside them. These could act as envelopes carrying drugs or toxins into the body and releasing them when they reach a destination.
- This can improve drug efficacy and bioavailability
risks of nanotech/particles for health
- Can potentially absorb through the skin and go into your blood stream and into cells
- The particles may interact with biomolecules to cause unwanted chemical reaction
- A side effect of excessive silver consumption, which is usually through nanoparticles, is argyria. This is when silver compounds accumulate in the skin, turning the skin blue-grey
benefits of nanoparticles for the environment
- nanobeads can be used to trap and remove materials in wastewater treatment.
- Nanotechnology can also be used to protect the environment by cleaning up outdoor air pollution. It allows toxic gases to be removed from the air so that people can be protected from breathing in contaminants
risks of nanotech/materials for the environment
- Releasing nanoparticles of silver in large quantities into a delicate environment through wastewater from washing machines could change the balance of microbes, potentially damaging the system’s health
- They might contaminate soil and migrate into surface and ground waters
- May be toxic to aquatic organisms
other benefits of nanomaterials/tech
- They can enhance the performance and lifespan of batteries
- Can be used in defence materials (e.g., bullet proof vests)
non-nanoscale zinc (for sunscreen) advantages and disadvantages
advantages: broad coverage against UVA, UVB, and blue light
disadvantages: white and visible on the skin
nanoscale zinc advantages and disadvantages
advantages: less visible on skin
disadvantages: not as broad coverage, nanoparticles could absorb into the blood stream
