Estimating Quantum Dot Size with Pulsed Field Gradient NMR

Pulsed field gradient nuclear magnetic resonance (NMR)
is used
to estimate the size of quantum dots (QDs) produced in a simple, fast,
small-scale synthesis. This upper-division laboratory experiment teaches
the basics of QD synthesis and pulsed field gradient NMR, a powerful
technique for measuring diffusion coefficients in solution. The diffusion
coefficients are used to calculate hydrodynamic radii, which are compared
to core radii obtained from optical absorbance sizing curves, providing
insight into the structure of QDs in colloidal suspension and the
nature of the information provided by pulsed field gradient NMR.