A multifunctional composite superhydrophobic coating with anti-corrosion and wear resistance has been fabricated on the surface of the aluminum. The superhydrophobic coating resembles a sandwich ...structure that contains a silane coupling agent layer at the bottom, a SiO
2
-hybridized silicone resin adhesive layer at the middle, and a perhydropolysilazane (PHPS) layer on the top. The superhydrophobic multilayer coating not only effectively improved the corrosion resistance of metal surfaces but also had wear resistance. The contact angle of the aluminum was coated by PHPS and was 152.7°. The contact angle of aluminum with sandwich coating structure was 161.3°. Compared with the original aluminum, the corrosion current density of aluminum which was coated by PHPS coating and sandwich structure coating was decreased by 2 and 4 orders, respectively. What's more, the contact angle of the aluminum which was moved 1m on 600# SiC sandpaper under 1KPa pressure was decreased by 9°. Under the same conditions, the aluminum with a single PHPS coating was decreased by 70°. The study provides a valuable way not only to fabricate superhydrophobic surfaces on the aluminum but also modify the surface of commodity and industry supplies to facilitate their maintenance.
The micro-nano structures which are necessary factors to generate superhydrophobic performance are easily destroyed, especially by scraping with tough objects. As a result of the damage, ...superhydrophobicity will be lost. Herein, water-soluble polyvinyl alcohol(PVA) polymer binder is introduced to act as a cushion and sacrifice layer. In this approach, the aluminum surface with superhydrophobic is at the bottom. The PVA binder is in the middle. The topmost layer is the superhydrophobic polydimethylsiloxane (PDMS) and SiO2 layer. When the external force is weak, the bonding layer will act as a buffer to protect the underlying nanostructure. When the topmost layer is destroyed, the superhydrophobicity will be disappeared temporarily. Water can contact with the sacrifice layer, leading it to dissolution. Thus, the bonding layer is shedding, an intact aluminum superhydrophobic surface behind the sacrifice layer is uncovered. The method is critical to the applications of superhydrophobic Al materials in engineering.
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This paper studied Al6092/SiCp/β-LiAlSiO4 particle-reinforced aluminum matrix composites as the main object. Different solution aging treatment processes were selected to analyze the microstructure ...and mechanical properties of the specimens. The effects of solution aging on the microstructure, precipitation phases, and dislocations of the composites were revealed. The results showed that the solution aging treatment improved the stiffness and strength of Al6092/SiCp/β-LiAlSiO4 composites. On the one hand, solution aging promoted the generation of high dislocation density zones and Mg2Si precipitation phases in the samples, which increased the stress required for plastic deformation of the composites. In addition, the high modulus property of micron-sized SiCp can spontaneously carry loads, and the introduction of β-LiAlSiO4 promotes the dispersion of the reinforcing phase. In conclusion, the solution aging treatment and the particle-reinforced phase can jointly improve the deformation resistance of Al6092.
Abstract
This paper studied Al6092/SiC
p
/β-LiAlSiO
4
particle-reinforced aluminum matrix composites as the main object. Different solution aging treatment processes were selected to analyze the ...microstructure and mechanical properties of the specimens. The effects of solution aging on the microstructure, precipitation phases, and dislocations of the composites were revealed. The results showed that the solution aging treatment improved the stiffness and strength of Al6092/SiC
p
/β-LiAlSiO
4
composites. On the one hand, solution aging promoted the generation of high dislocation density zones and Mg
2
Si precipitation phases in the samples, which increased the stress required for plastic deformation of the composites. In addition, the high modulus property of micron-sized SiC
p
can spontaneously carry loads, and the introduction of β-LiAlSiO
4
promotes the dispersion of the reinforcing phase. In conclusion, the solution aging treatment and the particle-reinforced phase can jointly improve the deformation resistance of Al6092.
Text classification plays an important role in the areas of natural language processing and data mining. In general, a text is usually described around a collection of entities, i.e., the entities ...are the core part of the text. As a result, a deep understanding of the entities in a text benefits the classification of texts. To understand entities, traditional work tends to introduce concepts or web data for entities. However, we argue that the potential relations between entities are also important for the understanding of entity semantics, thus further supporting the classification of texts. In this paper, we focus on enhancing the performance of the existing text classification models by extracting features from entities with hierarchical graph learning. To this end, we mine the concepts of entities and the relations between them for a given text simultaneously, and further construct the semantic graph of the text. Then a novel hierarchical graph learning model is proposed to learn the graph embedding that well captures the node, relation, and graph structure information. Our experiments show that the proposed method has the ability to effectively improve the performance of the existing text classifiers.
Poly(3,4‐ethylene dioxythiophene) (PEDOT) is a promising electrochromic material in many practical application, such as smart windows and displays. However, there are still difficulties in currently ...realizing green manufacturing, high coloration efficiency, and rapid response. Herein, in‐situ electrochemical polymerization of PEDOT:PSS/Reline films was suggested in aqueous solution. Deep eutectic solvents (DES) composed of choline chloride and urea (Reline) were employed as green solvents in reaction system and used as dopants for the PEDOT:PSS. The as‐prepared PEDOT:PSS/Reline films exhibited remarkable electrochromic properties, including great ion diffusion coefficient, fast reaction time (coloration response time was 1.4 s), prominent transmittance modulation (38%), high coloration efficiency (223 cm2/C) and excellent cyclic stability. Impressively, doping of Reline cannot only provide a green polymerization environment, but also significantly boost the electrochromic properties.
An in‐situ electrosynthesis of PEDOT:PSS/Reline film.
In this work, the copolymers were successfully synthesized by electrochemical polymerization of two monomers, bithiophene (BT) and 3,4-ethylenedioxythiophene (EDOT), in a lithium ...perchlorate/propylene carbonate (LiClO4/PC) solution. The as-prepared were characterized with the aid of cyclic voltammetry, colorimetric analysis, Fourier transform infrared spectroscopy, and Ultraviolet-visible spectroscopy. The electrochromic and colorimetric properties of copolymers poly(2,2′-bithiophene-co-3,4-ethylenedioxythiophene) (P(BT-co-EDOT)) and homopolymer poly(2,2′-bithiophene) (PBT) in 0.1 M LiClO4/PC solution were investigated, and the coloring process based on the redox reaction of the film was observed. When an anodic potential is applied, the copolymer P(BT-co-EDOT) films show a color change from blue-purple to blue-gray changes, and the homopolymer PBT shows a color change from orange to brown. In addition, spectroelectrochemistry studies indicate that copolymer P(BT-co-EDOT) has a lower optical band gap (1.73–1.87 eV) than homopolymer PBT. The copolymers P(BT-co-EDOT) show a high optical contrast (36.65–42.62%) and coloration efficiency (215.8–296.6 cm2 C−1). The copolymer P(BT1-co-EDOT1) demonstrates excellent redox cycling stability, with 90% of the original optical contrast maintained after 500 cycles, making it an ideal candidate for copolymers.
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•Copolymers based on BT and EDOT monomers can enrich the color variation of polythiophene.•During EC conversion, the copolymer film prepared via electrochemical copolymerization shifts from blue-purple to blue-gray.•The copolymer has a low optical band gap.•The copolymer has good electrochemical properties, electrochromic properties, and redox stability.
This research analyzes the impact of bank capital, liquidity and funding liquidity on sustainable bank lending in the Middle East and North Africa (MENA) region. An unbalanced panel dataset covering ...55 banks using ESG scoring criteria from 2010–2020 was employed for this purpose. Results indicate that higher capital and liquidity ratios hinder the MENA banking sector’s ability to improve its sustainable lending capacity. Funding liquidity has a positive and significant effect on sustainable bank lending growth, which suggests that funding liquidity raises sustainable bank lending capacity. Furthermore, the impact of funding liquidity on sustainable bank lending growth remains positive and statistically significant to all capital ratios. It implies that bank capital improves the relationship between funding liquidity and banks’ capacity to issue loans in the MENA region. Finally, the results of too-big-to-fail banks indicate that bank lending growth is positively affected by higher capital ratios. Hence, it may help them to increase their capacity to issue sustainable bank loans in the market. Overall the results are robust to principal component analysis and other estimation techniques like bootstrapped-based bias correction fixed effects.
Daqiuni clay is an aluminosilicate clay with unique properties that make it a promising ceramic precursor. Understanding its sintering behavior is crucial for quality control in manufacturing. This ...study aimed to investigate the phase evolution, densification process, and reaction kinetics during sintering of Daqiuni clay. A combination of X-ray diffraction (XRD), simultaneous thermogravimetric-differential scanning calorimetry (TG-DSC), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques were employed to comprehensively analyse the phase transformations. The densification behavior, apparent activation energies, and reaction mechanisms were elucidated through thermodilatometric analysis conducted at varying heating rates. Four stages were identified during sintering including dehydration, dehydroxylation, mullite formation, and partial melting. The maximum shrinkages at each stage were measured. Kissinger analysis yielded apparent activation energies of 122.90, 258.40, 361.98 and 348.69 kJ/mol for the dehydroxylation, mullite nucleation, mullite growth, and partial melting stages, respectively. The dehydroxylation and partial melting processes followed the mechanisms of 3rd order reaction and 3D diffusion. Mullite formation was a two-step nucleation and growth process following the JMA model. This study clarified the phase evolution of Daqiuni clay during sintering.
