In this study, a commercial and low-toxicity hydrazide-containing building block has been used to construct azine-linked covalent organic frameworks (COFs). New style COFs were constructed between flexible formic hydrazide (FH) and 1,3,5-triformylphloroglucinal (Tp) or 1,3,5-triformylbenzene (TFB). The two resulting COFs (TpFH and TFBFH) exhibited uniform hollow tubular morphology (20-50 nm for TpFH, 50-100 nm for TFBFH). Compared to hydrazine, FH has low-toxicity and is a flexible monomer, consisting of amine and aldehyde groups. The decomposition of FH slows down the reaction rate and the as-synthesized FH-series COFs (708 m g for TpFH and 888 m g for TFBFH) had higher specific surface area than hydrazine-series COFs (617 m g for TpAzine and 472 m g for TFBAzine). A detailed time-dependent investigation was carried out to interpret the mechanism of hollow structure formation, and Ostwald ripening possibly happens during the formation of hollow COF microstructures. Considering the porous and high density N, O elements of these materials, preliminary applications of the metal ions removal from aqueous solution and gas storage were implemented.
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http://dx.doi.org/10.1039/d1ra02104d | DOI Listing |
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December 2024
College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 211100, China.
Carbon nanotubes (CNTs) show great promise for microwave absorption (MA) due to their excellent electrical conductivity and lightweight properties, which are conferred by the one dimensional hollow tubular structure. However, the ambiguous intrinsic motivations behind the formation of CNTs and the intricate growth processes have resulted in a lack of a systematic methodology for precisely controlling their electromagnetic properties. Herein, a flexible CNTs regulation strategy is designed to develop, with the core focus being the directional growth of carbon atoms and the differential catalysis of metal sources.
View Article and Find Full Text PDFPolymers (Basel)
November 2024
School of Chemical Engineering, Northeast Electric Power University, Jilin 132012, China.
The advantages of aluminum-ion batteries in the area of power source systems are: inexpensive manufacture, high capacity, and absolute security. However, due to the limitations of cathode materials, the capacity and durability of aluminum-ion batteries ought to be further advanced. Herein, we synthesized a nitrogen-doped tubular carbon material as a potential cathode to achieve advanced aqueous aluminum-ion batteries.
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November 2024
School of Civil Engineering, University of Science and Technology Liaoning, No. 189 Qianshan Middle Road, Lishan District, Anshan City, 114051, Liaoning Province, People's Republic of China.
Connection method of lengthening the steel tube of circular hollow sandwich concrete-filled steel tube by inside lining tube and thread is proposed. Twelve circular hollow sandwich concrete filled steel tubular beam-column connected by thread through inside lining tube are designed and fabricated using the length of the thread along the axial direction, the working height of the thread, and the position of the thread as parameters; In addition, one unconnected specimen and two welded specimens also are designed and fabricated to conduct controlled experimental research. The test phenomena and failure modes, axial compressive load-compression curve, axial compressive load-lateral deflection curve, and axial compressive load-strain in steel tube curve, as well as bearing capacity, strength reservation, deflection curve shape, lateral stiffness, ductility and plane section assumption are analyzed.
View Article and Find Full Text PDFMater Horiz
November 2024
Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai, Yantai Zhongke Research Institute of Advanced Materials and Green Chemical Engineering, Yantai, 264006, China.
Fabricating tubular hydrogel models with arbitrary structural complexity and controllable diameters using an ultrafast, facile yet universal method is desirable for vascular prototypes yet still a great challenge. Herein, inspired by the denaturing ability of spider silks, a novel strategy to induce complexation applying highly concentrated alkali into a polyvinyl alcohol/ionic liquid (PVA/IL) solution, , alkali-induced molecular aggregation (AMA), is proposed to achieve such purpose. This strategy enables the rapid and facile fabrication of tubular hydrogel architectures with tunable diameters, controllable thicknesses, and excellent mechanical performance with a tensile strength of up to 1.
View Article and Find Full Text PDFFood Chem
February 2025
Department of Hygiene, Third Faculty of Medicine, Charles University, Ruská 87, 100 00, Prague 10, Czechia. Electronic address:
A tubular microdialysis probe is made from polysulfone hollow fibre for human haemodialysis, which has an inner diameter of 200 μm and a thickness of 20 μm. Milk is deposited to the outer surface of the hollow fibre and allowed to dry to form a dry sample. The tubular probe is then connected to the syringe pump and microdialysis of the dry sample into 0.
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