Browsing by Author "Braceras, Inigo"
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Item Plasma polymerized silylated ciprofloxacin as an antibiotic coating(2011-07-22) Braceras, Inigo; Azpiroz, Patxi; Briz, Nerea; Fratila, Raluca M.; Oyarbide, Joseba; Ipiñazar, Enrique; Úlvarez, Noelia; Atorrasagasti, Garbiñe; Aizpurua, Jesus M.; INGENIERÍA DE SUPERFICIES; TECNOLOGÍAS DE HIDRÓGENO; SG; VALORIZACIÓN DE RESIDUOS; BiomaterialesLocally applied antibiotics under temporally controlled release present many advantages over systemic clinical treatments, e.g. efficiency and side effects. This can be achieved by a coating on top of the medical device, in which the antibiotic is stored. This study presents the use of plasma polymerization to produce such a coating using N,O-bis-tert- butyldimethylsilylated ciprofloxacin (silylciprofloxacin) as a precursor. Once exposed to physiological media, the outer layers of the coating release the antibiotic by a hydrolysis reaction. Thus, the plasma process parameters can control the speed of liberation through the coating polymerization. Besides, this study shows that the release products present antibiotic activity against a number of bacteria: E. coli, P. aeruginosa, and S. aureus. Ciprofloxacin release dynamics can be controlled by coating plasma polymerization parameters, allowing local controlled delivery of active antibiotic in physiologic conditions, and thus higher efficiency and lower side effects.Item Wire arc additive manufacturing Ti6Al4V aeronautical parts using plasma arc welding: Analysis of heat-treatment processes in different atmospheres(2020) Artaza, Teresa; Suárez, Alfredo; Veiga, Fernando; Braceras, Inigo; Tabernero, Iván; Larrañaga, Oihane; Lamikiz, Aitzol; FABRIC_INTEL; Tecnalia Research & Innovation; INGENIERÍA DE SUPERFICIESPAW (Plasma Arc Welding), a WAAM (Wire Arc Additive Manufacturing) technology with high deposition rates, can produce metallic components, layer by layer, of varied sizes, from different alloys, yielding high mechanical performance. Two Ti6Al4V walls are manufactured in an inert argon atmosphere using WAAM-PAW to analyze the deposition process in terms of growth in height per layer, deposition process temperature, and cooling times. The properties of the walls are compared with the values obtained from a thermomechanical simulation and both the microstructural and mechanical properties of the annealed WAAM-PAW wall are studied. Moreover, the effect of the media on the oxidation layer and on the mechanical properties are also analyzed throughout the heat treatment process, as well as the microstructure of Ti6Al4V. Stable deposition rates were achieved for a high deposition ratio of Ti6Al4V at 2 kg/h, restricting the oxygen levels to under 100 ppm. No significant differences were found in either the microstructural or the mechanical properties following heat treatments in a vacuum, in air or in argon. All the heat-treated samples met the AMS4928 standard for Yield Strength (YS) and Ultimate Tensile Strength (UTS).