Printable Graphene Oxide Nanocomposites as Versatile Platforms for Immobilization of Functional Biomolecules

A series of novel nanocomposites containing graphene oxide (GO) suitable for stereolithography is presented. Different loads of GO are tested, identifying that these materials can be printed with concentrations up to 2.5 wt% GO, presenting improved mechanical properties for concentrations below 1.0 wt% GO. In this range, the nanocomposites exhibit higher strength and toughness when compared to the pristine resin. Microscopic analyses of the material demonstrate that this can be correlated with the good compatibility of GO with the resin, which favors its homogeneous dispersion in the form of flexible nanoplates. After manufacturing, the availability of GO to participate in surface modification reactions with chitosan (CHI) and an alkaline phosphatase (ALP) is evaluated. CHI and ALP are well-known to act as biological cues in biorecognition processes, evidencing that these nanocomposites are suitable as platforms for selective immobilization of functional biomolecules.This work was funded by the Ministry of Science, Innovation and Universities (TEC2017-86102-C2-2-R), the 2014-2020 ERDF Operational Programme and the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia (FEDER-UCA18-106586). Co-funding from UE and the research group INNANOMAT (ref. TEP-946) is also acknowledged. A.S.d.L. and M.d.l.M. acknowledge Ministry of Science, Innovation and Universities for their Juan de la Cierva Incorporacion postdoctoral fellowships (IJC2019-041128-I, IJCI-2017-31507). SEM and TEM measurements were carried out at the DME-SC-ICyT-ELECMI-UCA

Self-Assembly of CsPbBr3Perovskites in Micropatterned Polymeric Surfaces: Toward Luminescent Materials with Self-Cleaning Properties

In this work, we present a series of porous, honeycomb-patterned polymer films containing CsPbBr3 perovskite nanocrystals as light emitters prepared by the breath figure approach. Microscopy analysis of the topography and composition of the material evidence that the CsPbBr3 nanocrystals are homogeneously distributed within the polymer matrix but preferably confined inside the pores due to the fabrication process. The optical properties of the CsPbBr3 nanocrystals remain unaltered after the film formation, proving that they are stable inside the polystyrene matrix, which protects them from degradation by environmental factors. Moreover, these surfaces present highly hydrophobic behavior due to their high porosity and defined micropatterning, which is in agreement with the Cassie-Baxter model. This is evidenced by performing a proof-of-concept coating on top of 3D-printed LED lenses, conferring the material with self-cleaning properties, while the CsPbBr3 nanocrystals embedded inside the polymeric matrix maintain their luminescent behavior.This work was funded by the Ministry of Science, Innovation and Universities (project TEC2017-86102-C2-2-R) and Junta de Andalucía (Research group INNANOMAT, ref. TEP-946) and co-financed by the 2014-2020 ERDF Operational Programme and by the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia (ref: FEDER-UCA18-106586). Co-funding from UE is also acknowledged. A.S.d.L. acknowledges the Ministry of Science, Innovation and Universities for his Juan de la Cierva Incorporación postdoctoral fellowship (IJC2019-041128-I). R.A. also acknowledges the support of the Spanish MINECO through projects: Retos-Colaboración 2016 Project Safetag (no. RTC-2016-5197-2) and Retos de la Sociedad Project Nirvana (no. PID2020-119628RB-C31) by MCIN/AEI/10.13039/ 501100011033 and the “Agencia Valenciana de la Innovació” for the Valorització 2018 Project Hidronio (no. INNVAL10/ 18/032) and Valorització 2021 Project CATIOX (no. INNVA1/2021/56). R.A. also thanks the Spanish MINECO for their Ramón y Cajal Fellowship (no. RYC-2015-18349). SEM and TEM measurements were carried out at the DME-SCICyT- ELECMI-UCA

Modification of the mechanical properties of core-shell liquid gallium nanoparticles by thermal oxidation at low temperature

Gallium nanoparticles (Ga NPs) are attracting increasing attention because of their appealing physical-chemical properties. In particular, their mechanical properties play a key role in the implementation of these core-shell structures on certain applications, such as soft and stretchable electronics. Thus, efforts are being addressed to modulate them mainly by chemical means. In contrast, this study investigates how the mechanical properties of the outer gallium thin oxide shell change when its thickness is increased through a thermal oxidation strategy. Specifically, as-deposited Ga NPs, as well as those subjected to thermal oxidation at 300 °C for three different times, are studied by performing single-particle indentations by atomic force microscopy over a wide range of NP radius. This analysis helps to confirm that the Reissner's thin-shell model for small deformations within the elastic regime is obeyed. From these data, the dependence of the shell stiffness and the Young's modulus of the gallium oxide on the thermal treatment is obtained. It is found that the shell stiffness increases with the annealing time, even by a factor of 50 under prolonged thermal oxidation, while the gallium oxide Young's modulus, close to 30 GPa, does not change significantlyThis research was supported by Spanish MINECO (Grants No. MAT2017-85089-C2-1R, CTQ2017-84309-C2-2-R, PID2019-106339GB-I00, PID2020-113142RB-C21) and the TRANSNANOAVANSENS program (Grant No.S2018/NMT-4349) from the Comunidad de Madrid and Junta de Andalucía (Research group INNANOMAT, ref. TEP-946). Co-funding from UE was also acknowledged. A.R.C. acknowledges Ramón y Cajal program (under Contract No. RYC-2015-18047). S.C.G and M.d.l.M. acknowledge Juan de la Cierva en Formación programmes (references FJC2019-041616-I and IJCI-2017-31507, respectively). F.J.P. was thankful for financial support by A.E. Consejo Superior de Investigaciones Científicas (under Grant No. CSIC-2019AEP150). TEM measurements were carried out at DME-SC-ICyT-UCA/ICTS-ELECM

“Proyecto Schizzo”, los sistemas gráficos en la prefiguración proyectual

Las experiencias pedagógicas del Taller Schizzo fueron creadas como un medio para investigar el potencial dialéctico entre representación y creación arquitectónica con la intención de introducir a los estudiantes de arquitectura en la problemática de los sistemas gráficos convergentes al proceso proyectual arquitectónico. Esta experiencia pedagógica pretendió reunir los métodos y la didáctica específica de ambas prácticas; considerando que el estudiante debe comprender la disciplina del diseño en forma integrada, sin discernir el instrumento de la actividad proyectual. Durante los años 2002, 2003 y 2004 se han llevado a cabo el desarrollo y práctica de cursos que reunieron estas características siendo los resultados sumamente interesantes y alentadores aunque provisorios ya que resulta necesario y natural producir una serie de modificaciones para el perfeccionamiento de las experiencias. (Párrafo extraído del texto a modo de resumen) Eje temático: Diseños curriculares innovadoresFacultad de Bellas Arte

“Proyecto Schizzo”, los sistemas gráficos en la prefiguración proyectual

Las experiencias pedagógicas del Taller Schizzo fueron creadas como un medio para investigar el potencial dialéctico entre representación y creación arquitectónica con la intención de introducir a los estudiantes de arquitectura en la problemática de los sistemas gráficos convergentes al proceso proyectual arquitectónico. Esta experiencia pedagógica pretendió reunir los métodos y la didáctica específica de ambas prácticas; considerando que el estudiante debe comprender la disciplina del diseño en forma integrada, sin discernir el instrumento de la actividad proyectual. Durante los años 2002, 2003 y 2004 se han llevado a cabo el desarrollo y práctica de cursos que reunieron estas características siendo los resultados sumamente interesantes y alentadores aunque provisorios ya que resulta necesario y natural producir una serie de modificaciones para el perfeccionamiento de las experiencias. (Párrafo extraído del texto a modo de resumen) Eje temático: Diseños curriculares innovadoresFacultad de Bellas Arte

“Proyecto Schizzo”, los sistemas gráficos en la prefiguración proyectual

Las experiencias pedagógicas del Taller Schizzo fueron creadas como un medio para investigar el potencial dialéctico entre representación y creación arquitectónica con la intención de introducir a los estudiantes de arquitectura en la problemática de los sistemas gráficos convergentes al proceso proyectual arquitectónico. Esta experiencia pedagógica pretendió reunir los métodos y la didáctica específica de ambas prácticas; considerando que el estudiante debe comprender la disciplina del diseño en forma integrada, sin discernir el instrumento de la actividad proyectual. Durante los años 2002, 2003 y 2004 se han llevado a cabo el desarrollo y práctica de cursos que reunieron estas características siendo los resultados sumamente interesantes y alentadores aunque provisorios ya que resulta necesario y natural producir una serie de modificaciones para el perfeccionamiento de las experiencias. (Párrafo extraído del texto a modo de resumen) Eje temático: Diseños curriculares innovadoresFacultad de Bellas Arte

TEDNet: Twin Encoder Decoder Neural Network for 2D Camera and LiDAR Road Detection

[EN] Robust road surface estimation is required for autonomous ground vehicles to navigate safely. Despite it becoming one of the main targets for autonomous mobility researchers in recent years, it is still an open problem in which cameras and LiDAR sensors have demonstrated to be adequate to predict the position, size and shape of the road a vehicle is driving on in different environments. In this work, a novel Convolutional Neural Network model is proposed for the accurate estimation of the roadway surface. Furthermore, an ablation study has been conducted to investigate how different encoding strategies affect model performance, testing 6 slightly different neural network architectures. Our model is based on the use of a Twin Encoder-Decoder Neural Network (TEDNet) for independent camera and LiDAR feature extraction, and has been trained and evaluated on the Kitti-Road dataset. Bird’s Eye View projections of the camera and LiDAR data are used in this model to perform semantic segmentation on whether each pixel belongs to the road surface. The proposed method performs among other state-of-the-art methods and operates at the same frame-rate as the LiDAR and cameras, so it is adequate for its use in real-time applications.SIThis work is partially supported by Universidad de León, under the ”Programa Propio de Investigación de la Universidad de León 2021” grant

Further Studies on the Physical and Biogeochemical Causes for Large Interannual Changes in the Patagonian Shelf Spring-Summer Phytoplankton Bloom Biomass

A very strong and persistent phytoplankton bloom was observed by ocean color satellites during September - December 2003 along the northern Patagonian shelf. The 2003 bloom had the highest extent and chlorophyll a (Chl-a) concentrations of the entire Sea-viewing Wide Field-of-view Sensor (SeaWiFS) period (1997 to present). SeaWiFS-derived Chl-a exceeded 20 mg/cu m in November at the bloom center. The bloom was most extensive in December when it spanned more than 300 km across the shelf and nearly 900 km north-south (35degS to 43degS). The northward reach and the deep penetration on the shelf of the 2003 bloom were quite anomalous when compared with other years, which showed the bloom more confined to the Patagonian shelf break (PSB). The PSB bloom is a conspicuous austral spring-summer feature detected by ocean color satellites and its timing can be explained using the Sverdrup critical depth theory. Based on high-resolution numerical simulations, in situ and remote sensing data, we provide some suggestions for the probable mechanisms responsible for that large interannual change of biomass as seen by ocean color satellites. Potential sources of macro and micro (e.g., Fe) nutrients that sustain the high phytoplankton productivity of the Patagonian shelf waters are identified, and the most likely physical processes that maintain the nutrient balance in the region are discussed

Additive Manufacturing of Gold Nanostructures Using Nonlinear Photoreduction under Controlled Ionic Diffusion

Multiphoton photoreduction of photosensitive metallic precursors via direct laser writing (DLW) is a promising technique for the synthesis of metallic structures onto solid substrates at the sub-micron scale. DLW triggered by a two photon absorption process is done using a femtosecond NIR laser (lambda = 780 nm), tetrachloroauric acid (HAuCl4) as a gold precursor, and isinglass as a natural hydrogel matrix. The presence of a polymeric, transparent matrix avoids unwanted diffusive processes acting as a network for the metallic nanoparticles. After the writing process, a bath in deionized water removes the gold precursor ions and eliminates the polymer matrix. Different aspects underlying the growth of the gold nanostructures (AuNSs) are here investigated to achieve full control on the size and density of the AuNSs. Writing parameters (laser power, exposure time, and scanning speed) are optimized to control the patterns and the AuNSs size. The influence of a second bath containing Au3+ to further control the size and density of the AuNSs is also investigated, observing that these AuNSs are composed of individual gold nanoparticles (AuNPs) that grow individually. A fine-tuning of these parameters leads to an important improvement of the created structures' quality, with a fine control on size and density of AuNSs.W.D.C. and M.G. acknowledge the support of the CNR Facility Beyond-Nano-Polo di Cosenza. W.D.C. acknowledges MIUR (Ministero dell'Istruzione, dell'Universita e della Ricerca-Italy) for her industrial PhD grant (PONa3_00362). This work was also funded by Ministry of Science, Innovation and Universities (project TEC2017-86102-C2-2-R) and Junta de Andalucia (Research group INNANOMAT, ref. TEP-946). Co-funding from UE is also acknowledged. A.S.d.L. and M.d.l.M. acknowledge Ministry of Science, Innovation and Universities for their Juan de la Cierva Incorporacion postdoctoral fellowships (IJC2019-041128-I, IJCI-2017-31507). SEM and TEM measurements were carried out at the DME-SC-ICyT-ELECMI-UCA. Documen

Polymer nanocomposites for plasmonics: In situ synthesis of gold nanoparticles after additive manufacturing

A series of nanocomposites containing gold nanoparticles (AuNPs) are prepared by stereolithography (SL) by simply adding a precursor (KAuCl4) to a photoresist. A thermal treatment is performed after manufacturing the nanocomposites, triggering the reduction of KAuCl4 into AuNPs in solid state. In this approach, the photopolymerization of the resin and the formation of the AuNPs occur independently, allowing the optimization of these two processes separately. Advanced electron microscopy analyses reveal the distribution, size and morphology of the AuNPs synthesized within the resin, showing the influence of the gold precursor concentration and different thermal treatments. The localized surface plasmon resonance (LSPR) of the AuNPs modifies the optical properties of the 3D-printed nanocomposites, yielding transparent yet colored materials even for concentrations as low as 0.1 wt% KAuCl4. This behavior can be modelled by the Mie theory, correlating the macroscopic properties of the nanocomposites with the individual AuNPs embedded in the resin. The possibility of tuning the LSPR of the AuNPs together with the ability of manufacturing 3D-structures with sub-millimeter precision by SL, paves the way for the design of advanced platforms for plasmonics, such as sensors for surface enhanced Raman spectroscopy9 página