Table II.

Zeta Potential of MWCNTs

Samples	Zeta potential (ζ; mV)
	Acidic pH	Neutral pH	Alkaline pH
Purified MWCNTs	+0.5 mV ± 0.015	+0.45 mV ± 0.010	−2.5 mV ± 0.134
Carboxylated MWCNTs	+0.14 mV ± 0.003	−1.10 mV ± 0.090	−14.1 mV ± 0. ± 0.46

Zeta potential was determined in PBS at 25°C by using a NICOMP ZLS 380 analyzer (PSS-NICOMP, Santa Barbara, USA)

Results are represented as mean ± SD (n = 3)