This study examined the effects of adding ethanol, a typical polar solvent, to an ethylene glycol–NaCl
electrolyte solution used for Ti electropolishing. The electropolishing range was determined by measuring
current density–voltage curve as a function of the ethanol concentration. When 20 vol.% ethanol was
added to the electrolyte solution, a mirror-like surface was obtained by adjusting the TiCl4 layer from
the substrate. With the exception of oxygen-bonded species, only metallic Ti was detected on the electropolished
surface with X-ray photoelectron spectroscopy. The minimum surface roughness, which was
measured with atomic force spectroscopy, was 2.341 nm