Chitosan and alginate layer-by-layer assembly on phynox (Co-Cr Alloy) surface modified by alkylcarboxylicammoniumphosphonate derivatives

Phynox is an austenitic cobalt-chromium alloy that presents a great variety of properties (such as good fatigue strength, resistance to corrosion and high passivity in contact with human tissues) that makes Phynox interesting where high mechanical performances are required for applications (such as springs in watch motors, aeronautical equipments, . . . ) and for biomedical applications. This work aims to study the deposition of polyelectrolyte multilayer (i.e. chitosan and alginate) on modified Phynox substrates and more specifically to compare different pathways for the deposition of the first chitosan layer. After the synthesis and the grafting of 11- methylundecanoateammoniumphosphonate (or NPCOOMe), the first chitosan layer has been deposited either by ionic interactions or by a covalent grafting via an amidation reaction (under conventional and induction heating) with the monolayer present on the modified Phynox substrate. The amidation reaction under induction heating leads to the grafting of a higher amount of chitosan. Finally, the feasibility of successive polyelectrolyte multilayer deposition has been demonstrated.