We show extensive theoretical studies related to the generation and characterization of 2D and 3D ordered networks using 1D units that are connected covalently. We experimentally created ...multi-terminal junctions containing 1D carbon blocks in order to study the most common morphologies and branched structures that could be used in the theoretical design of network models. We found that the mechanical and electronic characteristics of ordered networks based on carbon nanotubes (ON-CNTs) are dominated by their specific super-architecture (hexagonal, cubic, square, and diamond-type). We show that charges follow specific paths through the nodes of the multi-terminal systems, which could result in complex integrated nanoelectronic circuits. The 3D architectures reveal their ability to support extremely high unidirectional stress when their mechanical properties are studied. In addition, these networks are shown to perform better than standard carbon aerogels because of their low mass densities, continuous porosities, and high surface areas.
► API X52 steel corrosion in H
2SO
4 was evaluated with EIS. ► The corrosion inhibition efficiency of six thiadiazole compounds were evaluated. ► The alkyl chain length of these compounds was related ...to their corrosion IE. ► 2-Amino-5-undecyl-1,3,4-thiadiazole, IC-11, was the best inhibitor at 100
ppm. ► IC-11 corrosion inhibition lasted over 90% for at least 720
h.
The corrosion inhibition efficiency of 2 amino 5 alkyl 1,3,4 thiadiazole compounds with different alkyl chain lengths, namely: 2 ethyl, 3
n propyl, 5
n penthyl, 7 hepthyl, 11 undecyl and 13 tridecyl, was evaluated in the system steel/1
M H
2SO
4. These compounds were synthesized, characterized by FT-IR and NMR spectroscopy analysis and evaluated using electrochemical impedance spectroscopy and SEM analysis. The results showed that the inhibition mechanism involves blockage of the steel surface by the inhibitor molecules by a Langmuir-type adsorption process and that the alkyl chain length plays an important role in the inhibition efficiency of the synthesized inhibitors.
Effect of TiO2 particle and pore size on DSSC efficiency González-Verjan, V. A.; Trujillo-Navarrete, B.; Félix-Navarro, Rosa María ...
Materials for renewable and sustainable energy,
07/2020, Volume:
9, Issue:
2
Journal Article
Peer reviewed
Open access
In this work, we report the preparation of TiO
2
nanoparticles with a high surface area, from 120 to 168 m
2
g
−1
by the hydrothermal-microemulsion route and hydrothermal temperature effect over ...particle size, porosity, and photovoltaic parameter. The TiO
2
samples were characterized by Raman, BET, TEM, SEM-FE, I–V curves, and EIS. The increase of hydrothermal temperature correlates with particle and pore size. Although when the synthesis temperature was 250 °C, the surface area presents an unexpected decrease of c.a. 28%. TiO
2
samples were employed as thin-film photo-anodes for dye-sensitized solar cell (DSSC) solar cells. Photovoltaic results showed that the sample prepared at 250 °C presented the more suitable textural properties for the DSSC application. The prepared TiO
2
materials with a particle size of 6.93 ± 0.59 nm and anatase crystalline phase favor electron transport and diffusion of electrolyte species, which directly impact in solar cell efficiency.
Introduction: We aimed to analyze the anthropometric and body composition profiles of Down syndrome (DS) adults; to describe their dietary habits, nutrient intake, and physical activity patterns; and ...to identify the related risk factors which may influence their health status and quality of life.
Methods: A cross-sectional study was conducted on a cohort of 23 DS adults (45% women) aged 21-44 years. Anthropometry and body composition were assessed by bioelectrical impedance. Dietary nutrient intake was assessed quantitatively using a 72-h recall. A food frequency questionnaire and the prevention with Mediterranean diet-PREDIMED questionnaire were used for qualitative rating.
Results: Higher fat mass (FM) and lower lean mass (LM), bone mass (BM), and waist to hip ratio (WHR) were observed in women compared to men. LM and BM decreased, and body mass index (BMI), FM, and WHR increased with aging (all P < 0.05). Vitamin D and iodine intakes were not met by 70% and 60% of the studied participants, respectively. A total of 82% of the participants consumed less than 5 portions of fruits and vegetables per day and overconsumed food groups such as sweets and snacks and red meat (> 2 times per week). Protein intake showed a significant positive correlation with height (r = 0.489, P < 0.05), whereas fat intake was positively correlated with sweets and snacks (r = 0.521, P < 0.05).
Conclusion: The present findings support the existence of poor anthropometric and body composition profiles, and diet quality, underscoring the need for an interdisciplinary team assessment to enhance health and quality of life in DS adults.
Multifuncionality in polycrystalline multiferroic ceramics can be improved using an advanced synthesis process. In this work, core–shell design is being proposed to enhance the transport properties ...of biferroic YCrO3. The atomic layer deposition (ALD) thin-film growth technique was used for the YCrO3/Al2O3 (Y@Al) nanocomposite fabrication. A continuous, amorphous, and uniform Al2O3 shell, a few nanometers thick, was obtained and characterized by X-ray photoelectron spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy. The transport properties of biferroic YCrO3 coated with 50, 500, and 1000 ALD cycles of insulating Al2O3 were investigated using magnetization and AC conductivity measurements. It is observed that the values of the magnetic coercive field and the magnetization are affected by the amorphous and partially crystallized Al2O3 shell. Additionally, the Y@Al nanocomposite experiments show a notorious decreasing in the loss tangent and the electrical conductivity. Accordingly, hysteresis loops in the polarization versus electric energy data confirm the decrease of the leakage current as a consequence of the Al2O3 shell acting as a barrier layer. The results shown here confirm that the core–shell architecture is a promising alternative for improvement of the magnetic and ferroelectric properties in bulk multiferroics.
Pure and doped boron nitride nanotubes Terrones, M.; Romo-Herrera, J.M.; Cruz-Silva, E. ...
Materials today,
20/May , Volume:
10, Issue:
5
Journal Article
Peer reviewed
Open access
More than ten years ago, it was suggested theoretically that boron nitride (BN) nanotubes could be produced. Soon after, various reports on their synthesis appeared and a new area of nanotube science ...was born. This review aims to cover the latest advances related to the synthesis of BN nanotubes. We show that these tubes can now be produced in larger amounts and, in particular, that the chemistry of BN tubes appears to be very important to the production of reinforced composites with insulating characteristics. From the theoretical standpoint, we also show that (BN)-C heteronanotubes could have important implications for nanoelectronics. We believe that BN nanotubes (pure and doped) could be used in the fabrication of novel devices in which pure carbon nanotubes do not perform very efficiently.
The engineering of advanced materials capable of mimicking the cellular micro-environment while providing cells with physicochemical cues is central for cell culture applications. In this regard, ...paper meets key requirements in terms of biocompatibility, hydrophilicity, porosity, mechanical strength, ease of physicochemical modifications, cost, and ease of large-scale production, to be used as a scaffold material for biomedical applications. Most notably, paper has demonstrated the potential to become an attractive alternative to conventional biomaterials for creating two-dimensional (2D) and three-dimensional (3D) biomimetic cell culture models that mimic the features of in vivo tissue environments for improving our understanding of cell behavior (e.g. growth, cell migration, proliferation, differentiation and tumor metastasis) in their natural state. On the other hand, integration of plasmonic nanomaterials (e.g. gold nanoparticles) within the fibrous structure of paper opens the possibility to generate multifunctional scaffolds equipped with biosensing tools for monitoring different cell cues through physicochemical signals. Among different plasmonic based detection techniques, surface-enhanced Raman scattering (SERS) spectroscopy emerged as a highly specific and sensitive optical tool for its extraordinary sensitivity and the ability for multidimensional and accurate molecular identification. Thus, paper-based plasmonic substrates in combination with SERS optical detection represent a powerful future platform for monitoring cell cues during cell culture processes. To this end, in this review, we will describe the different methods for fabricating hybrid paper-plasmonic nanoparticle substrates and their use in combination with SERS spectroscopy for biosensing and, more specifically, in cell culture applications.
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In this work, we reported a novel green chemistry method for the synthesis of novel Pd NPs-PTH-CNTs hybrid material. Effect of PTH on the size and dispersion degree of Pd NPs was investigated and ...correlated with composite catalytic activity in the ORR and amaranth electro-photodegradation. The catalytic activity of Pd NPs-PTH-CNTs material is compared with control materials Pd NPs-PTH and Pd NPs-CNTs. PTH incorporation as reducing agent in the deposition of Pd NPs over CNTs promoted the control of particle size and improved their dispersion over the whole CNT surface; also, increase 50% more ORR catalytic activity in the production of H2O2 with the decrease of Pd particle size. This improvement allowed to remove 95% of amaranth with a lower current consumption in the electro-photodegradation. It should be highlighted the green chemistry approach through the synthesis of nanocomposites by eco-friendly methods in one step.
Scheme of hybrid material of carbon nanotubes-polythiophene-palladium particles for oxygen reduction and producing peroxide hydrogen in the photocatalytic degradation of amaranth with low charge consumption. Display omitted
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