SUPPLEMENTARY INFORMATION-S1
Hierarchical titania nanostructures prepared with focused ion beam-assisted anodisation
of titanium in an aqueous electrolyte
Pradeep K Yadav1, Patrick Lemoine1*, Graham Dale1, Jeremy WJ Hamilton1, Patrick SM
Dunlop1, John A Byrne1, Pascal Mailley2, Colin Boxall3
(1) Nanotechnology and Integrated Bioengineering Center, University of Ulster at
Jordanstown, Shore road,
Newtownabbey BT37 0QB United Kingdom
(2) LETI-DTBS-SBSC, 17 rue des martyrs 38054 Grenoble cedex 9 France.
(3) Engineering Department, Lancaster University, LA1 4YW, United Kingdom.
*To whom correspondence should be addressed. Tel: +44 (0)2890368054; Fax: +44
(0)2890366863;
E-mail: p.lemoine@ulster.ac.uk
The mechanical polishing was carried out with a Struers Tegra System, using a standard
procedure for titanium Step 1: SiC-paper at 300 RPM and 111 kPa pressure for 2 min, Step 2:
MD-Largo with DiaPro diamond paste at 150 RPM and 133 kPa pressure for 5 min and Step 3:
Silica, 1, 3 Butandiol and H2O at 150 RPM SiC-paper at 300 RPM and 155 kPa pressure for 10
min. AFM analysis prior to anodisation indicates that polishing reduced the R a value of the
metallic surface from 95 nm to 5 nm and the specific surface area difference from 18.5% to
0.3%. Despite this, polishing had no effect on the anodisation current versus time curve.
An SEM micrograph of the titania native tubes for the as received titanium is shown in figure
S1a. Such images were analyzed with a particle analysis algorithm using Image J, giving
information on the tube diameters d0 (in nm), tube cross-sectional eccentricities e (major axis to
minor axis ratio expressed in %), tube areal densities  (in m-2) and tube occupancies o (ratio
of measured to hexagonally-close packed density expressed in %). The result of this analysis is
shown in figure S1b. For information, the values are also shown for the native tubes alongside
the FIB supertubes, as in figure 3 (termed FIB-treated on figure S1b). Statistically analysed with
a t-test, the comparison between as received and polished titanium gives p-values always >=0.05
for all four quantities, indicating that there are no statistically significant differences between the
size, shape and organization of the native nanotubes for the as-received and polished metal
plates (d0=101±22 nm, e=128±20 %, =57.5± 3.6 m-2 and e=51±5).
Figure S1a: SEM micrographs of native nanotube arrays, grown for unpolished titanium with a
higher magnification image in the insert, the space bars represent 500 nm.
160
140
as received
120
polished
100
FIB-treated
80
60
40
20
0
diameter
exentricity
tube density
occupancy
Figure S1b: Statistical analysis of SEM micrographs for native titania tubes grown on asreceived Titanium, polished titanium and FIB-treated titanium (i.e. native nanotubes within
supertubes). The bar chart gathers result from image analysis by image J of tube diameter (in
nm), tube cross-sectional eccentricity ( major axis to minor axis ratio expressed in %), tube areal
density (in m-2) and occupancy (ratio of measured to hexagonally-close packed density
expressed in %).