Table 1.

Primary size, surface area and surface pH of titanate nanomaterials.

Sample	TF-1	TF-2	TNP
Primary sizea (nm)	54±31	73±21	170±51
Hydrodynamic diameter
•In water (nm)	373±10	639±5	353±1
•In RPMIb (nm)	447±48	810±126	530±15
Zeta potential
•In water (mV)	−45.23±0.91	−51.17±0.75	−11.47±1.1
•In RPMIb (mV)	−10.83±0.57	−10.22±1.02	−9.43±0.67
Fiber lengthc (µm)	2.3±0.6	7.4±2.7	n.d.
Surface area (m2/g)	35	29	8
Surface pHd	1.2–2.9	10.6–12	2.9–3.0
pH
•In water	7.75	9.51	7.35
•In RPMIb	7.86	7.91	7.84

n.d., not defined.

^aDiameter of TiNFs as measured from TEM images.

^bComplete culture media.

^cFiber length as measured from 3D optical microscope images.

^dAcid-base strength analysis using Hammett indicators.