Table 1.

Physicochemical properties of the ZnO powders/dispersions.

ZnO NP	SSA [m2/g]	dBET [nm]	dDLS [nm]		PDI		Zeta Potential [mV]
			Medium	Water	Medium	Water	Medium	Water
<50 nm	23.2	<50	198 ± 2	205 ± 1	0.15 ± 0.02	0.25 ± 0.01	−8.1 ± 2.3	0.04 ± 1.01
<100 nm	13.3	<100	256 ± 2	240 ± 2	0.16 ± 0.02	0.13 ± 0.02	−6.7 ± 3.2	−0.10 ± 0.84

SSA: specific surface area (determined by the Brunauer-Emmett-Teller [BET] method); d_BET: primary particle diameter (provided by the manufacturer); d_DLS: mean hydrodynamic diameter (from the DLS intensity distribution (zeta average)); PDI: polydispersity index; SSA and d_BET were measured as nanopowder; d_DLS, PDI, and zeta potential were measured as 1229 µmol/L ZnO NP dispersion in a cell culture medium and water after ultrasonication.