A molecular design strategy is used to construct ordered mesoporous Ti 3+ ‐doped Li 4 Ti 5 O 12 nanocrystal frameworks (OM‐Ti 3+ ‐Li 4 Ti 5 O 12 ) by the stoichiometric cationic coordination assembly process. Ti 4+...
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A molecular design strategy is used to construct ordered mesoporous Ti 3+ ‐doped Li 4 Ti 5 O 12 nanocrystal frameworks (OM‐Ti 3+ ‐Li 4 Ti 5 O 12 ) by the stoichiometric cationic coordination assembly process. Ti 4+ /Li + ‐citrate chelate is designed as a new molecular precursor, in which the citrate can not only stoichiometrically coordinate Ti 4+ with Li + homogeneously at the atomic scale, but also interact strongly with the PEO segments in the Pluronic F127. These features make the co‐assembly and crystallization process more controllable, thus benefiting for the formation of the ordered mesostructures. The resultant OM‐Ti 3+ ‐Li 4 Ti 5 O 12 shows excellent rate (143 mAh g −1 at 30 C) and cycling performances (<0.005 % fading per cycle). This work could open a facile avenue to constructing stoichiometric ordered mesoporous oxides or minerals with highly crystalline frameworks.
The sodium‐ion battery is a promising battery technology owing to its low price and high abundance of sodium. However, the sluggish kinetics of sodium ion makes it hard to achieve high‐rate performance, therefore im...
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The sodium‐ion battery is a promising battery technology owing to its low price and high abundance of sodium. However, the sluggish kinetics of sodium ion makes it hard to achieve high‐rate performance, therefore impairing the power density. In this work, a fiber‐in‐tube Co 9 S 8 ‐carbon(C)/Co 9 S 8 is designed with fast sodiation kinetics. The experimental and simulation analysis show that the dominating capacitance mechanism for the high Na‐ion storage performance is due to abundant grain boundaries, three exposed layer interfaces, and carbon wiring in the design. As a result, the fiber‐in‐tube hybrid anode shows a high specific capacity of 616 mAh g −1 after 150 cycles at 0.5 A g −1 . At 1 A g −1 , a capacity of ca. 451 mAh g −1 can be achieved after 500 cycles. More importantly, a high energy density of 779 Wh kg −1 and power density of 7793 W kg −1 can be obtained simultaneously.
Because of the chiral nature of the building blocks of living matter, an optical phenomena associated with the chirality constitute an important topic in physical chemistry. The specific optical rotation, which is a p...
Because of the chiral nature of the building blocks of living matter, an optical phenomena associated with the chirality constitute an important topic in physical chemistry. The specific optical rotation, which is a parameter for the characterization of the natural optical activity, depends strongly on the conformation of the molecule. In this study, we investigated the dependence of the optical rotation on a molecular conformation in the gas phase by calculating the electronic states of seven kind of chiral amino acids using the DV-Xα method. As a result, we can confirm the existence of an antibonding orbital on the side chain and the optical rotations are strongly related.
The synthesis and characterization is reported of (C 9 NH 20 ) 2 SnBr 4 , a novel organic metal halide hybrid with a zero‐dimensional (0D) structure, in which individual seesaw‐shaped tin (II) bromide anions (SnBr 4...
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The synthesis and characterization is reported of (C 9 NH 20 ) 2 SnBr 4 , a novel organic metal halide hybrid with a zero‐dimensional (0D) structure, in which individual seesaw‐shaped tin (II) bromide anions (SnBr 4 2− ) are co‐crystallized with 1‐butyl‐1‐methylpyrrolidinium cations (C 9 NH 20 + ). Upon photoexcitation, the bulk crystals exhibit a highly efficient broadband deep‐red emission peaked at 695 nm, with a large Stokes shift of 332 nm and a high quantum efficiency of around 46 %. The unique photophysical properties of this hybrid material are attributed to two major factors: 1) the 0D structure allowing the bulk crystals to exhibit the intrinsic properties of individual SnBr 4 2− species, and 2) the seesaw structure enabling a pronounced excited state structural deformation as confirmed by density functional theory (DFT) calculations.
Cationic frameworks can selectively trap anions through ion exchange, and have applications in ion chromatography and drug delivery. However, cationic frameworks are much rarer than anionic or neutral ones. Herein, we...
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Cationic frameworks can selectively trap anions through ion exchange, and have applications in ion chromatography and drug delivery. However, cationic frameworks are much rarer than anionic or neutral ones. Herein, we propose a concept, preemptive coordination (PC), for targeting positively charged metal–organic frameworks (P‐MOFs). PC refers to proactive blocking of metal coordination sites to preclude their occupation by neutralizing ligands such as OH − . We use 20 MOFs to show that this PC concept is an effective approach for developing P‐MOFs whose high stability, porosity, and anion‐exchange capability allow immobilization of anionic nucleotides and coenzymes, in addition to charge‐ and size‐selective capture or separation of organic dyes. The CO 2 and C 2 H 2 uptake capacity of 117.9 cm 3 g −1 and 148.5 cm 3 g −1 , respectively, at 273 K and 1 atm, is exceptionally high among cationic framework materials.
Weight reduction is one of the big challenges in the auto industry. In the aerospace industry, the high modulus of composite material makes weight savings to replace alloys such as aluminium and titanium. It is one wa...
Weight reduction is one of the big challenges in the auto industry. In the aerospace industry, the high modulus of composite material makes weight savings to replace alloys such as aluminium and titanium. It is one way to reduce fuel consumption and reducing emissions in vehicles by using composite. Among them, carbon fiber and glass fiber are the most useful materials in composite to reduce the weight in vehicles not only in the automotive field but also in aircraft, marine, medicine, sport, etc. In this study, hand lay-up (wet lay-up) method is used to fabricate carbon fiber and glass fiber composites with different curing temperature 30°C (the equivalent of room temperature) until it is dry and 80°C for curing 6 hours. The strength of carbon fiber and glass fiber composites were increased over 10% and the hardness of carbon fiber composite was also increased two times at 80°C curing temperature. Furthermore, the fracture mechanism of carbon fiber and glass fiber composites were also observed by using Scanning Electron Microscopy (SEM) image processing method.
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