Nanomaterials Flashcards
What is nanomaterial?
Solid material with dimension between 1-100nm
What is nanoscience?
The study of new effects in 1-100nm dimensions
What is nanotechnology?
Procedures for creating new functions in the nano dimensions
What is the Plasmonic effect?
The effect of vibrations of electrons at the same frequency of light
Fabrication of nanomaterial is through top down or bottom up. What is meant by this?
Top down is going from a bigger to a smaller material through physical interactions
Bottom up is going from atomic level and getting bigger materials, through controlled organization
What are advantages of solution phase?
Can use low temperatures, which helps with reaction conditions, solids need heat. Solutions can be fine tuned
what are the 3 steps of solution phase?
1) Add a solvent to the reactant. SOlvation of reactant species and additives
2) There is a formation of a stable solid crystal nuclei from the solution
3) The crystal growth is controlled to a certain size through the addition of reactant species.
What is Ostwald ripening?
It is when the solid crystal dissolves and then grows on another crystal, you get different size crystals.
How is Ostwald ripening mitigated?
Using surfactants/stabilizers
Why are thiols good stabilizers for gold Au?
Because like gold, thiols are also soft
What is the Brust-Schiffrin method?
It is a type of reaction that uses a phase transfer agent to produce gold nanoparticles.
Describe the Brust-Schiffrin method reaction
1) there is a phase transfer from water to toluene
2) there is a reduction reaction using sodium borohydride (the reducing agent)
What is chemical vapour deposition?
It is when chemical vapor is transported to a substrate where reaction and solid state nucleation occurs.
Where vpor interact or decompose a substrate and adsorb onto the surface, then combine to create a solid
How might diamond be made
Using chemical vapor deposition
Ga(CH3)3 (g) + AsH3 (g) -> heat ->
Ga(CH3)3 (g) + AsH3 (g) -> heat -> GaAs(s)+3CH4(g)
What is another name for semiconducting nanoparticles?
Quantum dots
What two effects happen in quantum confinement?
When the band gap increases vs the bulk and the energy levels of electrons in the LUMOs become quantized
Explain quantum confinement
When there is trapping electrons and holes in a small region,, when the material gets smaller, the bandgap increases, and the minimum energy for interband transitions will increase
Give an example of special optical properties and quantum confinement in real life applications?
LED, CdSe
The color changes just by changing the size of the material
