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The deposition of organic semiconductors (OSCs) using solution shearing deposition techniques is highly appealing for device implementation. However, when using high deposition speeds, it is necessary to use very concentrated OSC solutions. The OSCs based on the family of dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) have been shown to be excellent OSCs due to their high mobility and stability. However, their limited solubility hinders the processing of these materials at high speed. Here, we report the conditions to process alkylated DNTT and the S-shaped π-core derivative S-DNTT by bar-assisted meniscus shearing (BAMS) at high speed (i.e., 10 mm s-1). In all the cases, homogeneous thin films were successfully prepared, although we found that the gain in solubility achieved with the S-DNTT derivative strongly facilitated solution processing, achieving a field-effect mobility of 2.1 cm2 V-1 s-1, which is two orders of magnitude higher than the mobility found for the less soluble linear derivatives., This work was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 811284 (UHMob), the Spanish Ministry (project GENESIS PID2019-111682RB-I00 and through the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE CEX2019-000917-S)) and the Generalitat de Catalunya (2017-SGR-918). L. F. and J. L. are enrolled in the UAB Materials Science PhD program. J. L. acknowledges the Scholarship from the Chinese Council. G. S. is a FNRS research associate (Belgian National Fund for Scientific Research). G. S. acknowledges financial support from the Francqui Foundation (Francqui Start-Up Grant). Y. H. G. is thankful to FNRS for financial support through research projects Pi-Fast (No T.0072.18), Pi-Chir (No T.0094.22), and DIFFRA (No U.G001.19)., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

The use of blends of small molecule organic semiconductors (OSCs) with insulating binding polymers has been shown to be a promising route to facilitate the processing of OSCs over large areas using printing techniques. Here we fabricated organic field-effect transistors (OFETs) and phototransistors using the benchmark OSC 7-decyl-2-phenyl[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10) and blends of this material with polystyrene (PS), poly(pentafluorostyrene) (PFS) and poly(methyl methacrylate) (PMMA). We show that the nature of the binding polymer has a significant impact on the device performance. The OFETs showing the best performance are the ones based on blends of PS since they reveal less interfacial traps, leading to devices with higher mobility, threshold voltage close to zero and high bias stress stability. The lowest OFET performance is found in the devices based on PMMA blends due to the higher density of majority charge carrier (i.e., holes) traps. On the other hand, regarding the response of the devices to UV light, the PFS and pristine films exhibited the highest photoresponse, which was attributed to the higher density of minority charge carrier (i.e., electrons) traps. Therefore, this work demonstrates that the binding polymer is a useful tool to optimise the OFET electrical characteristics as well as its photoresponsivity., This work was funded by the projects GENESIS PID2019-111682RB-I0 and Severo Ochoa FUNFUTURE CEX2019-000917-S from MCINN/AEI/10.13039/501100011033/and by the Generalitat de Catalunya (2017-SGR-918). J. L. acknowledges funding from the Chinese Scholarship Council (CSC). J. L. is enrolled in the UAB Materials Science PhD program. S.R-G. acknowledges support from the Marie Skłodowska Curie Cofund, Beatriu de Pinós Fellowship (AGAUR-2019 BP 00200). R. P. acknowledges support from the Ramón y Cajal Fellowship (Ref. RyC2019-028474-I)., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

The deposition of organic semiconductors (OSCs) using solution shearing deposition techniques is highly appealing for device implementation. However, when using high deposition speeds, it is necessary to use very concentrated OSC solutions. The OSCs based on the family of dinaphtho[2,3

Molecular surfactants, which are based on a water-insoluble tail and a water-soluble head, are widely employed in many areas, such as surface coatings or for drug delivery, thanks to their capability to form micelles in solution or supramolecular structures at the solid/liquid interface. Electrolyte-gated organic field-effect transistors (EGOFETs) are highly sensitive to changes occurring at their electrolyte/gate electrode and electrolyte/organic semiconductor interfaces, and hence, they have been much explored in biosensing due to their inherent amplification properties. Here, we demonstrate that the EGOFETs and surfactants can provide mutual benefits to each other. EGOFETs can be a simple and complementary tool to study the aggregation behavior of cationic and anionic surfactants at low concentrations on a polarized metal surface. In this way, we have monitored the monolayer formation of cationic and anionic surfactants at the water/electrode interface with p-type and n-type devices, respectively. On the other hand, the operational stability of EGOFETs has been dramatically enhanced, thanks to the formation of a protective layer on top of the organic semiconductor by exposing it to a high concentration of a surfactant solution (above the critical micelle concentration). Stable performances were achieved for more than 10 and 2 h of continuous operation for p-type and n-type devices, respectively. Accordingly, this work points not only that EGOFETs can be applied to a wider range of applications beyond biosensing but also that these devices can effectively improve their long-term stability by simply treating them with a suitable surfactant., This work was funded by DGI (Spain) through project GENESIS PID2019-111682RB-I00, the Generalitat de Catalunya (2017-SGR-918), and the Spanish Ministry of Economy and Competitiveness through the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE CEX2019- 000917-S). A.T. acknowledges the FPU fellowship and is enrolled in the UAB Materials Science PhD program. F.L. gratefully acknowledges the “Juan de la Cierva” programme.

Thin films of the organic semiconductor Ph-BTBT-10 and blends of this material with polystyrene have been deposited by a solution shearing technique at low (1 mm s−1) and high (10 mm s−1) coating velocities and implemented in organic field-effect transistors. Combined X-ray diffraction and electrical characterisation studies prove that the films coated at low speed are significantly anisotropic. The highest mobility is found along the coating direction, which corresponds to the crystallographic a-axis. In contrast, at high coating speed the films are crystallographically less ordered but with better thin film homogeneity and exhibit isotropic electrical characteristics. Best mobilities are found in films prepared at high coating speeds with the blended semiconductor. This work demonstrates the interplay between the crystal packing and thin film morphology and uniformity and their impact on the device performance., The authors also thank the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 811284 (UHMob), the Spanish Ministry project GENESIS PID2019-111682RB-I00, the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE, CEX2019-000917-S), the Generalitat de Catalunya (2017-SGR-918) and the Austrian Science Fund (FWF): [P30222]. A. T. thanks his enrolment in the Materials Science PhD program of Universitat Autònoma de Barcelona and acknowledges FPU fellowship from the Spanish Ministry. We thank the synchrotron Elettra, Trieste for provision of synchrotron radiation and Luisa Barba for her support to use the beamline XRD1. G.S. acknowledges postdoctoral fellowship support from the Belgian National Fund for Scientific Research (FNRS). We acknowledge support of the publication fee from the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).

Herein, we report on the synthesis and structural characterization of novel charge transfer (CT) complexes of the benzothienobenzothiophene derivative C8O-BTBT-OC8 with the series of FxTCNQ derivatives (x = 2, 4). The degree of charge transfer and HOMO–LUMO gap energies were evaluated by spectroscopic means and by DFT calculations. Thin films of the (C8O-BTBT-OC8)(F4TCNQ) complex were prepared by a simple solution shearing technique and by blending the active materials with polystyrene. X-Ray diffraction and IR/Raman spectroscopy techniques were instrumental for the structural identification of the films, which belonged to the same phase as the resolved single crystal. The films were implemented as an active layer in organic field-effect transistor (OFET) devices, which exhibited an n-type behavior in ambient conditions in agreement with the theoretical calculations., This work was funded by European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 811284 (UHMob), the Spanish Ministry with the project GENESIS PID2019-111682RB-I00 and through the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE CEX2019-000917-S), the Generalitat de Catalunya (2017-SGR-918) and the Consortium des Equipements de Calcul Intensif (CECI), funded by the Fonds de la Recherche Scientifique de Belgique (F.R.S. – FNRS) under grant no. 2.5020.11. A. T. acknowledges his FPU fellowship. A. T and L. F. are enrolled in the UAB Materials Science PhD program. Y. G. is thankful to the Belgian National Fund for Scientific Research (FNRS) for financial support through research projects, Pi-Fast No. T.0072.18, and 2D to 3D No. 30489208. Financial supports from the French Community of Belgium (ARC No. 20061) is also acknowledged. DB is a FNRS research director, CQ is a FNRS research associate. S. D. acknowledges financial support from the University of Bologna (RFO-Scheme). TS thanks the European co-financing project FSE REACT EU – PON R&I 2014–2020., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

The use of additive manufacturing and different metallization techniques for prototyping radio frequency components such as antennas and waveguides are rising owing to their high precision and low costs. Over time, additive manufacturing has improved so that its utilization is accepted in satellite payloads and military applications. However, there is no record of the frequency response in the millimeter-wave band for inductive 3D frequency selective structures implemented by different metallization techniques. For this reason, three different prototypes of dielectric 3D frequency selective structures working in the millimeter-wave band are designed, simulated, and manufactured using VAT photopolymerization. These prototypes are subsequently metallized using metallic paint atomization and electroplating. The manufactured prototypes have been carefully selected, considering their design complexity, starting with the simplest, the square aperture, the medium complexity, the woodpile structure, and the most complex, the torus structure. Then, each structure is measured before and after the metallization process using a measurement bench. The metallization used for the measurement is nickel spray flowed by the copper electroplating. For the electroplating, a detailed table showing the total area to be metallized and the current applied is also provided. Finally, the effectiveness of both metallization techniques is compared with the simulations performed using CST Microwave Studio. Results indicate that a shifted and reduced band-pass is obtained in some structures. On the other hand, for very complex structures, as in the torus case, band-pass with lower loss is obtained using copper electroplating, thus allowing the manufacturing of inductive 3D frequency selective structures in the millimeter-wave band at a low cost.

This work proposes a method for the evaluation of the effect of galvanic interactions between intergrown sulfide-mineral grains present in a thiosulfate leaching system, based on a combination of electrochemical measurements. Several common associated minerals in complex sulfide ore (CSO), as well as high purity sulfide minerals (pyrite, arsenopyrite, chalcopyrite, sphalerite, and galena), were used to develop and test the method. The reactivity of the CSO and each individual sulfide mineral in an ammoniacal thiosulfate solution was determined by voltammetry and chronoamperometry, using carbon paste electrodes and rotating disk electrodes (RDE). Secondary phase formation and the surface alteration of both the individual and associated minerals were evaluated by in-situ Raman spectroscopy and ex-situ cyclic voltammetry in 0.1 M NaNO3 aqueous solution. Chalcocite (Cu2S) and covellite (CuS) were identified as intermediate products of chalcopyrite leaching, while pyrite was oxidized to ferrous hydroxide and later to magnetite. Results showed that pyrite in CSO acts as a cathodic side, promoting the reduction of oxygen. Thus, the oxidation of pyrite was delayed due to the galvanic protection offered by arsenopyrite and chalcopyrite. Mineralogy and evaluation of the mineral textures both of the ore and its modification as a result of leaching were used to validate the method.

The implementation of organic semiconductor (OSC) materials in X-ray detectors provides exciting new opportunities for developing a new generation of biocompatible devices with high potential for the fabrication of sensitive and low-cost X-ray imaging systems. Here, the fabrication of high performance organic field-effect transistors (OFETs) based on blends of 1,4,8,11-tetramethyl-6,13-triethylsilylethynyl pentacene (TMTES) with polystyrene is reported. The films are printed employing a low cost and high-throughput deposition technique. The devices exhibit excellent electrical characteristics with a high mobility and low density of hole traps, which is ascribed to the favorable herringbone packing (different from most pentacene derivatives) and the vertical phase separation in the blend films. As a consequence, an exceptional high sensitivity of (4.10 ± 0.05) × 1010 µCGy–1cm–3 for X-ray detection is achieved, which is the highest reported so far for a direct X-ray detector based on a tissue equivalent full organic active layer, and is higher than most perovskite film-based X-ray detectors. As a proof of concept to demonstrate the high potential of these devices, an X-ray image with sub-millimeter pixel size is recorded employing a 4-pixel array. This work highlights the potential exploitation of high performance OFETs for future innovative large-area and highly sensitive X-ray detectors for medical dosimetry and diagnostic applications., This work was funded by the Spanish Government within: research projects GENESIS PID2019-111682RB-I00 and RTI2018-095460-B-I00, the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE CEX2019-000917-S) and the “María de Maeztu” program for Spanish Structures of Excellence (MDM-2017-0767). Funding was also provided by the Generalitat de Catalunya (2017-SGR-918, 2017-SGR13). A.T. acknowledges his FPU fellowship and is enrolled in the UAB Materials Science PhD program. C.M-D. acknowledges her Juan de la Cierva grant (ref. FJC2019-042161-I) from Ministerio de Ciencia e Innovación. I.F., A.C., B.F. and L.B. acknowledge funding from INFN through the CSN5 FIRE project. All the authors acknowledge Giuliana Tromba and Diego Dreossi at ELETTRA synchrotron in Trieste for hardware and software technical support during the experiments, in particular for the acquisition of X-ray image. R.S. acknowledges funding from MINECO under grant agreement CTQ2017-87773-P/AEI/FEDER., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

The molecule 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10) is an organic semiconductor with outstanding performance in thin-film transistors. The asymmetric shape of the molecule causes an unusual phase behavior, which is a result of a distinct difference in the molecular arrangement between the head-to-head stacking of the molecules versus head-to-tail stacking. Thin films are prepared at elevated temperatures by crystallization from melt under controlled cooling rates, thermal-gradient crystallization, and bar coating at elevated temperatures. The films are investigated using X-ray diffraction techniques. Unusual peak-broadening effects are found, which cannot be explained using standard models. The modeling of the diffraction patterns with a statistic variation of the molecules reveal that a specific type of molecular disorder is responsible for the observed peak-broadening phenomena: the known head-to-head stacking within the crystalline phase is disturbed by the statistic integration of reversed (or flipped) molecules. It is found that 7–15% of the molecules are integrated in a reversed way, and these fractions are correlated with cooling rates during the sample preparation procedure. Temperature-dependent in situ experiments reveal that the defects can be healed by approaching the transition from the crystalline state to the smectic E state at a temperature of 145 °C. This work identifies and quantifies a specific crystalline defect type within thin films of an asymmetric rodlike conjugated molecule, which is caused by the crystallization kinetics., This work was supported by the Fonds de la Recherche Scientifique (FNRS) and the Fonds voor Wetenschappelijk Onderzoek – Vlanderen (FWO) under EOS project 30489208 and the Austrian Science Fund (FWF): [P30222]. YG is also thankful to FNRS for financial support through research projects BTBT n° 2.4565.11, Phasetrans n° T.0058.14, Pi-Fast n° T.0072.18, and 2D to 3D No. 30489208. Financial supports from the French Community of Belgian (ARC n° 20061) and by the Walloon Region (WCS No. 1117306, SOLIDYE n° 1510602) are also acknowledged. G.S. acknowledges postdoctoral fellowship support from the FNRS. M.M. thanks the Spanish Ministry project GENESIS PID2019-111682RB-I00, the “Severo Ochoa” Programme for the Centers of Excellence in R&D (FUNFUTURE, CEX2019-000917-S), and the Generalitat de Catalunya (2017-SGR-918). A.T. is enrolled in the Materials Science PhD program of Universitat Autònoma de Barcelona and acknowledges FPU fellowship from the Spanish Ministry. The large-scale facility Elettra, Trieste, Italy, provided synchrotron radiation for grazing incidence X-ray diffraction experiments at the beamline XRD1.

The stability of organic semiconductors (OSCs) is strongly hampered by the presence of water molecules. One approach that has been proved to lead to organic field-effect transistors with an enhanced performance is the use of blends of OSCs with insulating binding polymers. In this work, the fabrication of OSC thin films based on polymeric ternary blends including a hydrophobic fluorinated polymer is reported as a novel route to engineer long-term reliable organic field-effect transistors (OFET) devices. In particular, OFETs based on blends of bis(triisopropylsilylethynyl)pentacene (TIPS) with polystyrene (PS) and poly(pentafluorostyrene) (PFS) are explored. The PS:PFS ratio is tuned in order to find the optimum formulation. It is shown that films including 20% of PFS in the polymeric blend exhibit an improved device performance, which is reflected by a low bias stress and an exceptional environmental stability, without significantly hampering the OFET mobility. This work advocates that adding a small percentage of fluorinated polymers in OSC blends is a promising route to realize more reliable and stable devices without importantly compromising the device mobility., This work was funded by the Spanish Ministry with the project GENESIS PID2019-111682RB-I00 and through the “Severo Ochoa” Programme for Centers of Excellence in R&D (FUNFUTURE CEX2019-000917-S) and the Generalitat de Catalunya (2017-SGR-918). A.T. acknowledges his FPU fellowship and is enrolled in the UAB Materials Science PhD program., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

Organic semiconductors (OSCs) are promising materials for costeffective production of electronic devices because they can be processed from solution employing high-throughput techniques. However, small-molecule OSCs are prone to structural modifications because of the presence of weak van der Waals intermolecular interactions. Hence, controlling the crystallization in these materials is pivotal to achieve high device reproducibility. In this perspective article, we focus on controlling polymorphism and morphology in small-molecule organic semiconducting thin films deposited by solution-shearing techniques compatible with roll-to-roll systems. Special attention is paid to the influence that the different experimental deposition parameters can have on thin films. Further, the main characterization techniques for thin-film structures are reviewed, highlighting the in situ characterization tools that can provide crucial insights into the crystallization mechanisms., This work was funded by the European Research Council (ERC) StG 2012-306826 e-GAMES project. The authors also thank the Networking Research Center on Bioengineering, Biomaterials, and Nanomedicine (CIBER-BBN), the Generalitat de Catalunya (2014-SGR-17), and the Spanish Ministry of Economy and Competitiveness through the project FANCY CTQ2016-80030-R and through the “Severo Ochoa” Programme for Centers of Excellence in R&D (SEV-2015-0496). A.T. is enrolled in the Materials Science Program of UAB and acknowledges FPU fellowship from the Ministry.

Here, we study the temperature-dependent transport properties of OFETs with the prototypical OSC 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) co-processed with polystyrene (PS) as the active layer. The active layer is deposited directly on SiO2 using the bar-assisted meniscus shearing (BAMS) method. The co-processing with PS favors a consequential decrease in interfacial trap densities as previously reported. Furthermore, we demonstrate how this processing method leads to devices exhibiting activation energies well below the current state of the art for TIPS-pentacene on SiO2 or other dielectrics. Altogether, our study reports on TIPS-pentacene thin films exhibiting an activation energy (Ea) as low as 15 meV when the active material is blended with PS and processed via BAMS. Such an unprecedentedly low value originates not only from a decrease in the interfacial trap densities but also from trapping energies much shallower than previously reported elsewhere for the same material. This allows us to clarify the previously reported notion that significant passivation of interfacial traps occurs following the separation of PS from TIPS-pentacene into an individual layer at the interface with the insulator and to confirm that the enhanced transport originates from a synergistic effect wherein both trapping density and depth are reduced., E.O. and I.S. acknowledge the financial support of the Natural Sciences and Engineering Research Council of Canada (NSERC) (funding Reference Nos. RGPIN-201805092 and RGPIN-2017-06748), the Fonds de recherche du Québec-Nature et technologies (FRQNT). E.O. also acknowledges the financial support of the Canadian Foundation for Innovation (CFI) through the John R. Evans Leaders Fund (JELF). M.M.T. acknowledges funding by the Spanish Ministry with the Project No. GENESIS PID2019-111682RB-I00 and through the “Severo Ochoa” Programme for Centers of Excellence in R&D (No. FUNFUTURE CEX2019-000917-S) and the Generalitat de Catalunya (No. 2017-SGR-918). A.T. acknowledges his FPU fellowship and is enrolled in the UAB Materials Science Ph.D. program. M.B.R. cordially thanks NSERC for support through the Canada Graduate Scholarships–Master's program and the Centre québécois sur les matériaux fonctionnels (CQMF) for his summer scholarship., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

RESUMEN: Este estudio presenta un análisis de corrosión del acero al carbono mediante pruebas de polarización electroquímica en un electrodo de disco rotatorio en varias condiciones de aireación e hidrodinámicas en solución 0,2 mol L-1 K2 SO4 a pH 3. Las reacciones implicadas en la disolución del acero se analizan estudiando Tafel regiones de las curvas de polarización, lo que confirma que el oxígeno disuelto desempeña un papel predominante en la corrosión del metal. La velocidad de corrosión fue 35 veces mayor en condiciones de aireación natural que en el medio desaireado. Bajo condiciones de aireación natural no es posible realizar un análisis simple de la corrosión del acero a partir de la extrapolación de las pendientes de Tafel, ya que tales pendientes no están bien definidas debido a la formación de óxido en la región anódica y a la influencia del transporte de masa en la región catódica. En los potenciales de polarización catódica y con aireación natural, hay un aumento en las corrientes de polarización con respecto al sistema desaireado y la reacción de reducción de oxígeno es controlada por el transporte de masa. Bajo condiciones desaireadas y en potenciales de polarización intermedios, hay un cambio en el mecanismo de disolución del acero. A altos sobrepotenciales, la velocidad de disolución del acero tiende a ser igual en ambos sistemas (aireado y desaireado), porque la corrosión del metal. Palabras clave: Acero al carbono, ley de Tafel, corrosión, sulfato, difusión de oxígeno. ABSTRACT: This study presents a corrosion analysis of carbon steel by electrochemical polarization tests on a rotating disk electrode at several aeration and hydrodynamic conditions in solution 0.2 mol L-1 K2 SO4 at pH 3. The reactions involved in the dissolution of the steel are analyzed by studying the Tafel regions of the polarization curves, confirming that the dissolved oxygen plays a predominant role in the corrosion of the metal. The corrosion rate was 35 times higher in natural aeration conditions than in the deaerated medium. Under natural aeration conditions, it is not possible to make a simple analysis of the corrosion of the steel from the extrapolation of the Tafel slopes since such slopes were not well defined due to the formation of rust in the anodic region and the influence of mass transport in the cathodic region. At cathodic polarization potentials and with natural aeration, there is an increase in polarization currents with respect to the deaerated system and the oxygen reduction reaction is controlled by the mass transport. Under deaerated conditions and at intermediate polarization potentials, there is a change in the dissolution mechanism of the steel. At high overpotential, the rate of dissolution of the steel tends to be equal in both systems, aerated and deaerated because the corrosion of the metal is controlled by the diffusion of species through corrosion products film. Keywords: Carbon steel, Tafel’s law, corrosion, sulfate, oxygen diffusion.

Despite the recent encouraging advances in achieving high‐performance organic field effect transistors employing meniscus‐guided processing techniques compatible with roll‐to‐roll manufacturing, there is still a very limited knowledge about how all the coating parameters influence the thin film electrical characteristics. Here, the polymorphism and morphology of thin films of the organic semiconductor dibenzo‐tetrathiafulvalene blended with polystyrene deposited by bar‐assisted meniscus shearing (BAMS) are investigated in‐depth by modifying the coating speed and ink formulation. It is found that all these parameters significantly affect the crystallization process and the resulting thin film characteristics. Remarkably, pure polymorphs with optimized field‐effect mobilities can be achieved only within a narrow range of conditions. The precise control of the film morphology and crystal structure is of paramount importance in order to move toward real applications achieving high device‐to‐device reproducibility., This work was funded by the European Research Council (ERC)StG 2012‐306826 e‐GAMES. The authors also thank the Spanish Ministry of Economy and Competitiveness with the project FANCY CTQ2016‐80030‐R and through the “Severo Ochoa” Programme for Centers of Excellence in R&D (SEV‐2015‐0496), the Generalitat de Catalunya (2017‐SGR‐918) and the Networking Research Center on Bioengineering, Biomaterials, and Nanomedicine (CIBER‐BBN). The authors thank the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement No 811284 (UHMob). The authors also thank the Elettra synchrotron for the allocation of beamtime on the XRD1 beamline and also thank Luisa Barba for experimental support. A.T. acknowledges a Fellowship from the Ministry and is enrolled in the PhD program of the Universitat Autònoma of Barcelona (UAB). The authors thank Dr. F. Leonardi for preparing the film for X‐ray characterization and Dr. Max Riera for developing a software for data analysis.

Water‐gated organic field‐effect transistors (WGOFETs) are expected to have a strong impact in the field of electronic biosensors owing to the synergism between the transduction function of the transistors with the fact that they can be operated in physiological media. Nonetheless, a limited library of gate electrodes has currently been explored for this aim. Herein, different polymer nanocomposite carbon paste gate electrodes (NC‐CPgEs) are successfully exploited for the first time as unusual nonmetal gate electrodes in WGOFET devices employing four types of carbon nanoallotropes with dimensionality ranging from 0D to 3D (i.e., carbon nanohorns, carbon nanotubes, reduced graphene oxide, and graphite, respectively). Interestingly, after an accurate electrochemical and electrical characterization, it is demonstrated that the WGOFETs with the developed NC‐CPgEs reveal excellent behaviors comparable to that achieved with conventional gate electrodes, such as gold or glassy carbon electrodes. Further, depending on the carbon nature the device performance can be tuned, being the devices based on reduced graphene oxide the ones showing a better electrical response. Accordingly, this work can pave the way for widespread applications of NC‐CPgEs for the development of a new generation of WGOFET devices based on carbon nanostructures., A.T. and J.M. contributed equally to this work. This work was funded by the Spanish Ministry/FEDER project FANCY CTQ2016‐80030‐R, the Networking Research Center on Bioengineering, Biomaterials, and Nanomedicine (CIBER‐BBN), the Generalitat de Catalunya (2017SGR918) and the Spanish Ministry of Economy and Competitiveness, through the “Severo Ochoa” Programme for Centers of Excellence in R&D (SEV‐2015‐0496). J.M. acknowledges his Juan de la Cierva grant. A.T. is enrolled in the Materials Science PhD program of Universitat Autònoma de Barcelona and acknowledges FPU fellowship from the Spanish Ministry.

Understanding the physics behind the operational mechanism of Electrolyte-Gated Organic Field-Effect Transistors (EGOFETs) is of paramount importance for the correct interpretation of the device response. Here, we report the systematic functionalization of the gate electrode of an EGOFET with self-assembled monolayers with a variety of dipolar moments showing that both the chemical nature and the monolayer density influence the electrical characteristics of the device., The authors thank the ERC StG2012-306826 e-GAMES project, the Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), the DGI (Spain) project FANCY CTQ2016-80030-R, the Generalitat de Catalunya (2017-SGR-918), and the Spanish Ministry of Economy and Competitiveness, through the “Severo Ochoa” programme for Centres of Excellence in R&D (SEV-2015-0496). F. L. gratefully acknowledges the “Juan de la Cierva” programme. The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the Seventh Framework Programme of the European Union (FP7/2007-2013) under Research Executive Agency Grant Agreement No. 600388 (TECNIOSpring programme), and from the Agency for Business Competitiveness of the Government of Catalonia, ACCIÓ. A. T. is enrolled in the UAB PhD program and he thanks the Spanish Ministry for a FPU fellowship.

This study presents a corrosion analysis of carbon steel by electrochemical polarization tests on a rotating disk electrode at several aeration and hydrodynamic conditions in solution 0.2 mol L-1 K2SO4 at pH 3. The reactions involved in the dissolution of the steel are analyzed by studying the Tafel regions of the polarization curves, confirming that the dissolved oxygen plays a predominant role in the corrosion of the metal. The corrosion rate was 35 times higher in natural aeration conditions than in the deaerated medium. Under natural aeration conditions, it is not possible to make a simple analysis of the corrosion of the steel from the extrapolation of the Tafel slopes since such slopes were not well defined due to the formation of rust in the anodic region and the influence of mass transport in the cathodic region. At cathodic polarization potentials and with natural aeration, there is an increase in polarization currents with respect to the deaerated system and the oxygen reduction reaction is controlled by the mass transport. Under deaerated conditions and at intermediate polarization potentials, there is a change in the dissolution mechanism of the steel. At high overpotential, the rate of dissolution of the steel tends to be equal in both systems, aerated and deaerated because the corrosion of the metal is controlled by the diffusion of species through corrosion products film.

Resumen Este artículo presenta los resultados de la evaluación del desempeño y metodologías de preparación superficial para la aplicación de un sistema de pinturas utilizado en tanques de lastre de embarcaciones marinas. Se caracterizaron las herrumbres típicas encontradas en superficies de embarcaciones, se realizaron pruebas de campo haciendo diferentes preparaciones de superficies en áreas de difícil acceso que permitieran controlar el grado de contaminación por sales solubles, comparando diferentes métodos (Método Bresle, Sleeve test, Saltsmart, cromatografía iónica) y varios perfiles de anclaje (sand blasting, grata y lija, escariador y piqueteo) con el fin de determinar la combinación de los métodos más eficientes en la práctica para la preparación de zonas de difícil acceso. Se evaluaron las propiedades de un sistema de pinturas en laboratorio y en campo durante 7 meses de exposición. Se encontró que los métodos de preparación de superficie por piqueteo y grata + lija son los que presentan el mayor contenido de sales (> de 10 μg/cm2), superando el límite máximo permitido de 5.0 μg/cm2. A partir del método de preparación con escariador están por debajo de los 10 μg/cm2. Abstract In this paper, different methodologies of surface preparation for applying a paint system used in ballast tanks of marine vessels are studied and their influences in the performance of the paint system are evaluated. Typical rusts found on boat surfaces were characterized, field tests were conducted with different surface preparations in hard-to-reach areas, controlling the contamination degree by soluble salts and comparing different methods (Bresle method, Sleeve test, Saltsmart test and ion chromatography) and different roughness profiles (sand blasting, power grinding and sandpaper, scraping and picketing) in order to determine the more efficient combination of methods for the surface preparation in hard-to-reach areas. Different properties of a paint system were evaluate during laboratory and field exposure tests. The final exposure time was 7 months. It was found that the methods of surface preparation by picketing and power grinding + sandpaper have the higher salt contents (> 10 μg/ cm2), exceeding the maximum permitted limit of 5.0 μg/cm2.

During the last decades, small molecule organic semiconductors have been successfully used as active layer in organic field-effect transistors (OFETs). Despite the high mobility achieved so far with organic molecules, in order to progress in the field it is crucial to find techniques to process them from solution. The device reproducibility is one of the principal weak points of organic electronics for further commercialization. To achieve a high device-to-device reproducibility it is essential to control the morphology and polymorphism of the active layer for OFET application. In this work, the preparation of thin films is reported based on blends of the organic semiconductor dibenzo-tetrathiafulvalene (DB-TTF) and polystyrene by a solution shearing technique compatible with upscaling. Here, it is demonstrated that varying the deposition parameters (i.e., speed and temperature) or the solution formulation (i.e., semiconductor/binder polymer ratio) is possible to control the film morphology and semiconductor polymorphism and, hence, the different intermolecular interactions. It is demonstrated that the control of the thermodynamics and kinetics of the crystallization process is key for the device performance optimization. Further, this is the first time that DB-TTF thin films of the α-polymorph are reported., This work was mainly funded by the European Research Council (ERC) StG 2012-306826 e-GAMES and ERC PoC 2014-640120 LAB-TECH projects. The authors also thank the Networking Research Center on Bioengineering, Biomaterials, and Nanomedicine (CIBER-BBN), the Generalitat de Catalunya (2014-SGR-17) and the Spanish Ministry of Economy and Competitiveness, through the projects BE-WELL CTQ 2013-40480-R and FANCY CTQ2016-80030-R, and through the “Severo Ochoa” Programme for Centers of Excellence in R&D (SEV-2015-0496). F.L. gratefully acknowledges the “Juan de la Cierva” programme.