Percolation threshold of acid-etched titanium from Minkowski’s functionals

Ramón-Torregrosa, P.J.¹, Rodríguez-Valverde, M.¹, and Cabrerizo-Vílchez, M.A.¹

1 Biocolloid and Fluids Physics Group. Department of Physics, Faculty of Sciences, University of Granada, Spain;

Minkowski’s functionals provide morphological and topological information of a rough surface such as connectivity. In the context of biomaterials, since the Euler characteristic relates to the possibility of fluid flow on a surface, it may be of interest in the prediction of biointegration. The Euler characteristic (third Minkowski’s functional) can be used to define a percolation threshold from the height level where the Euler characteristic function has its zero crossing. A high percolation threshold suggests better fluid retention properties..

In this work, we studied the evolution of commercially pure titanium (grade IV) subjected to an acid etching process. Each set of samples was attacked for different times, from 0 to 750 s with hidrofluoridhric acid. Topographies of each sample were achieved by AFM (Nanoscope IV) in Tapping Mode.

We present the evolution of the maximum-density height for the peaks and valleys with etching time and the concerning percolation thresholds.