Selective desorption of organophosphonates on chemically functionalized titanium by Direct Laser Patterning

Surface functionalization based on organophosphonate molecules and Direct Laser Patterning (DLP) technique both allow to design chemically patterned titanium surfaces devoted to biomaterial engineering. Ultrapolished surfaces of commercially pure titanium were modified with 16-phosphonohexadecanoic acid and octadecylphosphonic acid. The DLP technique with a green pulsed laser was applied to selectively desorb the organophosphonate molecules on the functionalized titanium surfaces. Three regimes of laser ablation were found on the bare titanium surfaces as the ratio between the spot diameter and the interspot distance. Finally, the organophosphonate functionalized titanium surfaces subjected to DLP revealed different wettability domains with minimum impact on the roughness, validated by XPS, AFM and ESEM.