Surface Treatment of the Ti-Based Nanomaterials - Bionanomaterials for Dental Applications - page 263

im et al . [48] investigated TiO 2 nanoibers fabricated by
the electrospinning method using a mixture of Ti(IV)isopropoxide
and poly(vinyl pyrrolidone) (PVP) in acidic alcohol solution.
As-prepared nanoibers (Fig. 9.48) were immobilized on Ti plate
treated by NaOH/HCl by inducing the alcohol condensation reaction
of Ti(IV) isopropoxide with Ti-OH group on the titanium surface
and subsequent calcination (500-1000 o C). They found that the
diameter of the TiO 2 nanoibers can be controlled within the range of
20-350 nm by changing amounts of Ti(IV)isopropoxide and PVP.
Figure 9.48 SEM images of remaining nanoibers on NaOH/HCl-treated
Ti plate with alcohol condensation reaction [48].
Macak et al . [53] as well as Yang et al . [111] shows formation
of nanotubular layer in the sputtered Ti. Macak et al . [53] used
anodization of Ti deposited on Si, in 1M H 2 SO 4 + 0.15 wt% HF
electrolyte at potentials between 1 V and 25 V, which results in
tubes with diameter ranging from 30 to 100 nm. They investigated
the formation of nanotubes at different temperatures (-2 to 20°C)
[53]. At room temperature, an incubation time for self-organization
of up to 1 h is required. The higher is the electrolyte temperature,
the higher is the overall current density and thin ilm dissolution.
The lower the etching electrolyte temperature, the higher is the
current eficiency. At a lower temperature, the chemical dissolution
rate of TiO 2 is drastically reduced. They found that a temperature
of 2°C states an optimum to suppress the chemical dissolution
rate suficiently while not causing drastic precipitation of the
oxy-hydroxide (covering Ti surface in the early stage oxidation)