Table 1.

The zeta potential, average particle size estimated by XRD and TEM, and the atomic ratio of C to Zn (based on XPS data) of the ZnO NP samples made with different amounts of PAA

Samples	PAA amount (mg)	Zeta potential (mV)	XRD size (nm)	TEM size (nm)	C/Zn atomic ratio at the particle surface
1	0	+44.2	8.2	8.3	0.166
2	30	−9.9	8.4	8.5	0.301
3	60	−30.9	8.4	8.5	0.367

Abbreviations: XRD, X-ray diffraction; TEM, transmission electron microscopy; XPS, X-ray photoelectron spectroscopy; NP, nanoparticle; PAA, polyacrylic acid.