Nitinol is an alloy of great interest in general and especially in the biomedical field where many researches are aimed to improve both its corrosion resistance and its biocompatibility. In this work, we report on the advantage of an induction heating treatment in pure water compared to a conventional hydrothermal procedure. Both treatments lead to a hydroxylation of the surface, a decrease of the nickel amount in the outer part of the oxide layer, and a drastically decreased corrosion current density. However, the amount of surface hydroxyl groups is higher in the case of the induction heating treatment, which in turn leads to a denser grafting of atom transfer radical polymerization initiators and ultimately to a thicker 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate (MPC) polymer layer than in the case of conventional heating treatments. X-ray photoelectron spectroscopy (XPS), static contact angle, and polarization curves measurements as well as scanning electron microscopy (SEM) have been used to characterize the obtained modified surfaces.

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Low-pressure plasma polymerization of cyclopropylamine was employed for the surface functionalization of commercial ZnO, Al 2 O 3 , and ZrO 2 nanoparticles in a homemade hollow cathode plasma reactor. The analysis of the modified nanoparticles by X-ray photoelectron spectroscopy (XPS) revealed the incorporation of reactive functional groups such as primary and secondary amines, which was confirmed by Fourier transform infrared spectroscopy (FTIR). The raw and the plasma functionalized nanoparticles were evaluated in terms of dispersibility. Application of Hansen solubility parameters (HSP) theory showed that the efficient plasma polymerization that led to the deposition of an approximately 5 nm thick plasma polymer film, as determined by transmission electron microscopy (TEM), causes a similar shift toward the Hansen solubility space for the functionalized nanoparticles and changes their physicochemical affinity within selected solvents, regardless of the kind of nanoparticles used. Hence, a combined exploitation of nanoparticles having different cores is feasible in applications such as nanocomposites and bioapplications having certain reactivity after grafting an aminebased plasma polymer film that allows achieving a similar dispersibility.