Síntesis asistida por ultrasonido de nanoestructuras de compuestos de níquel

Tesis doctoral inédita, leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Inorgánica. Fecha de lectura:07-09-201

Electrophoretic deposition of nanostructured-TiO2/chitosan composite coatings on stainless steel

Novel chitosan composite coatings containing titania nanoparticles (n-TiO2) for biomedical applications were developed by electrophoretic deposition (EPD) from ethanol–water suspensions. The optimal ethanol–water ratio was studied in order to avoid bubble formation during the EPD process and to ensure homogeneous coatings. Different n-TiO2 contents (0.5–10 g L−1) were studied for a fixed chitosan concentration (0.5 g L−1) and the properties of the electrophoretic coatings obtained were characterized. Coating composition was analyzed by thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. Scanning electron microscopy (SEM) was employed to study both the surface and the cross section morphology of the coatings, and the thicknesses (2–6 μm) of the obtained coatings were correlated with the initial ceramic content. Contact angle measurements, as a preliminary study to predict hypothetic protein attachment on the coatings, were performed for different samples and the influence of a second chitosan layer on top of the coatings was also tested. Finally, the electrochemical behavior of the coatings, evaluated by polarization curves in DMEM at 37 °C, was studied in order to assess the corrosion resistance provided by the n-TiO2/chitosan coatings

Síntesis instantánea de Alfa-Ni(OH)2 nanométrico en disolución amoniacal

Procedimiento de obtención de α-Ni(OH)2 nanométrico en al menos una dimensión, caracterizado porque comprende la adición del nitrato de níquel (II) en forma sólida sobre la disolución acuosa amoniacal a una velocidad mínima suficiente para producir sobresaturacion. Preferentemente, el procedimiento comprende la adición de ultrasonidos.Peer reviewedConsejo Superior de Investigaciones Científicas (España)B1 Patente sin examen previ

Electrophoretic deposition of nanostructured TiO2/alginate and TiO2-bioactive glass/alginate composite coatings on stainless steel

Two alginate (Alg) based composite coatings on stainless steel AISI 316L substrates, one containing titania nanoparticles (n-TiO2) and another one a mixture (50/50 wt-%) of n-TiO2 and bioactive glass (BG), intended for biomedical applications, were developed by electrophoretic deposition (EPD) from ethanol/water suspensions. Different n-TiO2 (2–10 g L−1) and BG (1–5 g L−1) contents were studied for a fixed alginate concentration (2 g L−1), and the properties of the electrophoretically obtained coatings were characterised. Coatings with high ceramic content (up to 67 vol.-%) were obtained. The presence of BG particles improves the mechanical properties of the coatings by increasing the adhesion to the substrate and also accelerates the formation of hydroxyapatite after immersion of the coatings in simulated body fluid. The electrochemical behaviour of the coated substrates, evaluated by polarisation curves in Dulbecco’s modified eagle medium at 37°C, confirmed the corrosion protection function of the novel EPD coatings. The present polymer–ceramic composite coatings belong to an emerging family of bioactive, compliant coatings that are promising for a range of biomedical applications

Electrophoretic deposition of ZnO/alginate and ZnO-bioactive glass/alginate composite coatings for antimicrobial applications

Two organic/inorganic composite coatings based on alginate, as organic matrix, and zinc oxide nanoparticles (n-ZnO) with and without bioactive glass (BG), as inorganic components, intended for biomedical applications, were developed by electrophoretic deposition (EPD). Different n-ZnO (1–10 g/L) and BG (1–1.5 g/L) contents were studied for a fixed alginate concentration (2 g/L). The presence of n-ZnO was confirmed to impart antibacterial properties to the coatings against gram-negative bacteria Escherichia coli, while the BG induced the formation of hydroxyapatite on coating surfaces thereby imparting bioactivity, making the coating suitable for bone replacement applications. Coating composition was analyzed by thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) analyses. Scanning electron microscopy (SEM) was employed to study both the surface and the cross section morphology of the coatings. Polarization curves of the coated substrates made in cell culture media at 37 °C confirmed the corrosion protection function of the novel organic/inorganic composite coatings.L. Cordero-Arias thanks the German Academic Exchange Service (DAAD) for a scholarship. Dr. S. Cabanas-Polo acknowledges the financial support from the EU ITN FP-7 project GlaCERCo. The authors acknowledge Anja Friedrich, Ulrike Marten-Jahns, Helga Hildebrand and Elias Palpanes for the experimental support and Intrinsiq Materials Ltd. (UK) for supplying the ZnO nanoparticles