Abstract:
One dimensional (1-D) nanostructured layer with tunable aspect ratio holds the prodigious potential for
achieving smart surfaces with controlled wettability. Herein, a simple and cost-effective technique was employed
to develop the high quality and novel hexagonal boron nitride (h-BN) nanorods. These h-BN nanorods (BNNRs)
with tunable aspect ratio contained oriented aligned nanoparticles along the [0001] direction were prepared by
wet chemical reaction method using non-toxic precursor (melamine, urea and boric acid). Controlled chemical
reactions in applied atmosphere (Ar 90% + NH3 10%) play an important role to transform the morphological
growth and tune the aspect ratio (AR) of h-BN nanorods by simply varying the annealing temperature
(1100–1300 ◦C). The correlation between structural, morphological and wetting properties of prepared materials
were also investigated in detail. The behavior of wettability was also analyzed in term of water contact angle and
surface free energy using two complex models, Wu and Owens & Wendt. Overall, the effect of annealing temperature and atmosphere were accountable to trigger the growth (aspect ratio from ~2.5 to ~5.2) and wetting
behavior from hydrophobic to ~ super hydrophobic (contact angle from 127◦ to 145◦.). Produced at 1300 ◦C, the
highly oriented h-BN nanorods with large aspect ratio (AR) ~5.2 and excellent wettability (hydrophobicity
~145◦) may be a promising candidate for water repellent applications.
