Formation mechanism and hemocompatibility of the superhydrophobic surface on biomedical Ti–6Al–4V alloy

The superhydrophobic surface was prepared on biomedical Ti–6Al–4V alloy by hydrothermal treatment coupled with subsequent hydrophobic treatment. The surface morphologies, surface roughness, phase and elemental compositions, water contact angle and hemocompatibility of the superhydrophobic samples were investigated. The results show that the hydrothermally treated sample is mainly composed of Na 2 Ti 6 O 13 phase with some –OH groups. The surface morphologies of the hydrothermally treated samples change from feather-like structure to grass-like structure, and the surface roughness gradually increases with increasing the concentrations of NaOH solution. After hydrophobic treatment, the surface roughness of samples slightly decreases, and the water contact angles increase first, reaching the maximum value of 159.24° ± 1.89° at 3.75 mol/L, and then decrease with increasing the NaOH concentrations. The –C 8 H 4 F 13 low surface energy fluorides are grafted onto the surface of hydrothermally treated sample by a self-assembly dehydration reaction, resulting in the formation of the superhydrophobic surface. The superhydrophobic surface effectively decreases the hemolysis ratio and platelets adhesion, and prolongs the dynamic coagulation time, indicating that it greatly improves the hemocompatibility of the biomedical Ti–6Al–4V alloy. Graphical Abstract