Table 1.
Manufacturer's reported size (nm) | Morphology SEMb | Size by DLSc (nm), n = 3 | Surface charge by zeta at pH ~8 (mV), n = 2 | |
---|---|---|---|---|
Bulk | - | Irregular | 1920±151 | −14.8±1.2 |
Alfa Aesar 44904 |
70 | Irregular Angular |
274±8 | −18.5±1.2 |
Alfa Aesar 45409 |
40 | Rounded | 159±4 | −21.6±3.7 |
Alfa Aesar 45588 |
70 | Angular | 179±3 | −23.4±3.1 |
Consortium | 25 | Spheroid | 215±15 | −29.2±1.0 |
The Alfa Aesar nanoparticles (NPs) were observed to have highly polydisperse size distributions by SEM and are, on average, the primary particle size reported by the manufacturer. Error in DLS and zeta potential values is the standard deviation of the mean values reported by the instrument. Additional analysis of all five particles by X-ray diffraction confirmed materials as ZnO (Zincite).
SEM = Scanning electron microscopy.
DLS = Dynamic light scattering.