Question
The heat-up method developed by the Hyeon (“hyun”) lab controls this parameter by forming oleic acid complexes. For 10 points each:
[10h] Name this parameter that is “focused” by maintaining high concentrations in the diffusion-limited regime. The Bawendi lab developed a method that controls this parameter by rapidly adding reactants to a heated solution, briefly inducing supersaturation.
ANSWER: nanoparticle size [or quantum dot size; accept nanocrystallite size or nanocluster size; accept monodispersity or monodispersed in place of “size”; prompt on size focusing or width by asking “of what?”]
[10e] Both hot injection and heat-up form one of these mixtures with nanoparticles as the dispersed phase. These mixtures can be stabilized against flocculation by capping quantum dots with ligands.
ANSWER: colloids [accept colloidal quantum dots]
[10m] Quantum dot emission is tunable because they are smaller than the Bohr radius of these quasiparticles, whose two constituents are bound together by Coulombic forces.
ANSWER: excitons
<Chemistry>
Summary
| 2024 ACF Nationals | 2024-04-21 | Y | 6 | 16.67 | 100% | 50% | 17% |