Artículos SCI

In this work, the 0.67BiFeO(3)-0.33BaTiO(3) ferroelectric ceramic was prepared by Reaction Flash Sintering (RFS). This preparation technique combines synthesis and sintering in a single Flash experiment. The starting oxides reacted during the flash to produce a stoichiometric well-sintered solid solution at a temperature of 858 degrees C by applying a modest field of 35 V cm(-1). The process takes place in a matter of seconds, which allows obtaining a pure perovskite structure without secondary phases. X-ray diffraction (XRD) results show the mixture of rhombohedral and pseudocubic phases expected for a composition that lies within a morphotropic phase boundary (MPB) region, since a significant splitting is observed in the reflections at 2 theta values of 39 degrees and 56.5 degrees. The microstructure exhibit a peculiar bimodal grain size distribution that determines the electrical properties. As compared with previous results, flash-prepared 0.67BiFeO(3)-0.33BaTiO(3) evidences smaller grain size, as well as slightly lower remanent polarization (P-r) and smaller coercive field (E-c) under similar electric fields. It is also demonstrated that the preparation by RFS provides benefits regarding electrical energy consumption.

Fabrication of tunable wetting surfaces is sought for the last years given its importance on energy, biomaterials and antimicrobials, water purification, microfluidics, and smart surfaces. Liquid management on surfaces mainly depends on the control at the micro- and nanoscale of both roughness and chemical composition. Herein, the combination of a soft-template method and plasma-enhanced chemical vapor deposition is presented for the synthesis of TiO2 nanofibers on porous substrates such as cellulose and stainless-steel membranes. The protocol, carried out under mild conditions, produces 3D nanomembranes with superhydrophobicity and oleophilicity that are tested as microliter water/oil filters. Photoactivation of TiO2 by UV illumination provides a straightforward approach for wetting tunability that converts the surface into amphiphilic. A final chemical modification of the TiO2 nanofibers by embedding them in an elastomeric polymeric shell and by fluorine-based grafting opens the path toward the formation of superomniphobic and self-cleaning surfaces with long-lasting lifetimes. Thus, a reliable procedure is demonstrated for the fabrication of TiO2 nanofibers, which allows the modification of porous supports and provides an innovative route for the development of 3D nanomembranes with under design wetting. This protocol is extendable to alternative metal oxides, metals, and core@shell nanoarchitectures with potential multifunctionalities.