BUSCADOR RECOLECTA

This paper reports the use of the electrospinning technique for the synthesis of nanocomposite micro/nanofibers by combining a polymeric precursor with hydrophobic behavior like polyvinyl chloride (PVC) with nanoparticles of a corrosion inhibitor like ZnO. These electrospun fibers were deposited on substrates of the aluminum alloy 6061T6 until forming a coating around 100 m. The effect of varying the different electrospinning deposition parameters (mostly applied voltage and flow-rate) was exhaustively analyzed in order to optimize the coating properties. Several microscopy and analysis techniques have been employed, including optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Water contact angle (WCA) measurements have been carried out in order to corroborate the coating hydrophobicity. Finally, their corrosion behavior has been evaluated by electrochemical tests (Tafel curves and pitting potential measurements), showing a relevant improvement in the resultant corrosion resistance of the coated aluminum alloys., This research was funded by the Spanish Economy and Competitiveness Ministry, FEDER (Project TRA2013-48603-C4-1-R-HELADA) and by the Public University of Navarra collaboration research grant PRO-UPNA 18 (6107).

In this work, a novel coating was deposited on aluminum alloy samples by using a combination of electrospinning and chemical vapor deposition (CVD-silanization) techniques in order to create a functionalized film with an enhancement of both corrosion resistance and hydrophobicity. The electrospinning technique makes the fabrication of highly crosslinked electrospun fibers possible by the combination of both poly(acrylic acid) and beta-cyclodextrin, respectively, which can be easily functionalized in a further step by using the CVD-silanization process due to the evaporation of a hydrophobic molecule such as 1H,1H,2H,2H-Perflurodecyltriethoxysilane. In addition, the resultant electrospun fibers with a high degree of insolubility have been successfully fabricated and metal oxide nanoparticles (TiO(2)NPs) have been incorporated into the electrospun polymeric solution in order to improve the corrosion protection. The surface morphology has been determined by using light optical microscopy, atomic force microscopy, scanning electron microscopy, and water contact angle (WCA) measurements. The corrosion resistance has been evaluated by using both potentiodynamic polarization and pitting corrosion tests. Finally, the results related to WCA measurements after CVD-silanization corroborate that the surfaces have been successfully functionalized with a hydrophobic behavior in comparison with the electrospinning process, showing a considerable difference in the roughness., This work was funded by the Spanish Economy and Competitiveness Ministry-FEDER Proyecto Retos (TRA2013-48603-C4-1-R) and the Public University (Navarre-PRO-UPNA18 (6107)).

In this work, we present a study about the generation and analysis of optical resonances caused by gold
nanorods (GNRs) embedded in films. GNRs were embedded in polymeric thin films using the Layerby-Layer nanoassembly (LbL) deposition technique. Polymer/GNRs thin films of different thicknesses
were deposited on the surface of cladding removed optical fibers for sensing. The spectral responses of
the optical fiber sensors were monitored during the build-up of the thin films. The generation of two
Localized Surface Plasmon Resonances (LSPRs) associated to the GNRs was observed in thinner coatings.
These devices with around 12 polymer/GNRs bilayers were characterized as refractometers, providing
an intensity-based sensitivity up to 75.69 dB/RIU. For thicker polymer/GNRs overlays, both LSPRs bands
were also generated and, additionally, it was observed a new Lossy Mode Resonance (LMR) band due
to modes coupled to the sensitive coating. The dependence of these three resonance bands with the
surrounding refractive index was studied. Finally, these sensors were tested in a climatic chamber in the
20-90% relative humidity (RH) range and the LMR showed a good sensitivity to RH changes while the
LSPR bands remained very stable in comparison. Results showed an excellent sensitivity of 11.2 nm/%RH
for the LMR, confirming the potential of this type of optical fiber sensor based on the combination of
LSPRs and LMRs bands., This work was supported in part by the Spanish Ministry of Economy and Competitiveness - CICYT-FEDER TEC2013-43679R, TEC2016-79367-C2-2-R, TEC2016-78047-R and TRA2013-48603-C4-1-R Research Grants, and a UPNA post-doctoral research grant.