Producción CyT
75TH Annual Meeting - Evaluation of graphene oxide (GO) coating on Mg-alloy for clinical applications: study of different conditions for GO deposition
Congreso
Autoría:
CERE, SILVIA ; Tano de la Hoz, María Florencia ; Fioravanti, federico ; Vanina Usach ; patricia Setton ; Gabriela Lacconi ; Katunar, M.RFecha:
2024Editorial y Lugar de Edición:
ISEResumen *
Diu to their characteristics as biodegradable and bioabsorbable material, magnesium (Mg) based alloys are very much studied as novel metallic materials for clinical application [1]. Peripheric nerve injuries affect to 1.3 millions of people around the world. The use of implant is the indicated to heal the injury when the gap between the damage nerve is greater than 5 mm. These implants serve as conduits and Mg alloys are the key components, however their fast degradation in aqueous electrolytes is not solved yet. A wide variety of surface modifications have been employed in order to enhance its corrosion resistance in physiological environments [1]. Considering this biomedical application, graphene oxide (GO) has emerged as a potential coating for Mg-alloys [1] due to its good electrical conductivity, biocompatibility and its high surface area [2]. Nevertheless, there are some significant challenges associated with GO coating, related to the size and shape of GO defects [2], which are influenced by the deposition methods and working conditions applied. Regarding this, the choice of those is crucial for generating GO coatings. In the present work, the immersion method, under different conditions, to deposit GO on AZ31 alloy and the influence of GO on the alloy corrosion behavior were studied. For activating the surface of the commercial AZ31 alloy (Dugopa S.A.- Spain), the samples were immersed into NaOH solution (AZ31-OH). After, AZ31-OH alloy was immersed into GO for 1 h. (AZ31-OH-GO1h) or 3 h. (AZ31-OH-GO3hrs). The morphology, chemical composition and corrosion behavior were analyzed using: SEM, FTIR and electrochemical assays. SEM images showed corrosion products on AZ31-OH surface, while on AZ31-OH-GO1h/3hrs, characteristic morphology of GO [1] coating were evident (Fig. 1A). It is important to note that after 3 h. of immersion, certain defects of the structures were observed. After immersions, the IR spectra exhibited peaks around 620-860 cm−1, 1430 cm−1, 3200-3600 cm−1 and 1734 cm−1 attributed to MgO/Mg(OH)2, C–H/ O–H, O–H and C=O bonds, respectively. Those results indicated the deposition of GO on the alloy. According to the EIS assays, at low frequencies, AZ31-OH and AZ31-OH-GO displayed higher impedance values compared to polished AZ31 (Fig. 1B), indicating that the coatings enhance the corrosion resistance of the alloy. Moreover, at low frequencies, AZ31-OH-GO3hrs exhibited the highest phase angle associated with a high resistance to charge transfer. At high frequencies, all of the conditions showed a higher phase angle compared to polished AZ31. This behavior corresponds to dense coatings, as SEM images showed, and the observed differences were related to their discontinuous surfaces. It is necessary to continue studying AZ31-OH-GO to further analyze the effect of the deposition method on the maintenance of GO properties and to evaluate AZ31-OH-GO degradation over time. Información suministrada por el agente en SIGEVAPalabras Clave
DEGRADATIONMAGNESIUMORTHOPEDIC IMPLANTS