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155 results on '"Yuan, Binfang"'

6. Sodium catalytic phenylpentazole cracking: a theoretical study.

Author

Zhang, Fulan, Yuan, Binfang, Guo, Xiaogang, and Huang, Huisheng

Abstract

This work presents an in-depth investigation into the cracking reaction mechanism of phenylpentazole (C6H5N5) under the catalytic influence of sodium metal, utilizing density functional theory. The geometries of the reactants, transition states, intermediates, and products are meticulously optimized employing the GGA/PW91/DNP level of theory. Also, a rigorous analysis is undertaken, encompassing various key factors including configuration parameters, Mulliken charges, densities of states, and reaction energies. Three distinct reaction pathways are comprehensively examined, shedding light on the intricate details and intricacies of each pathway. The results show that a remarkable outcome in which the activation energy of the C6H5N5 cracking reaction releases N2, facilitated by catalytic metal Na, reveals a strikingly reduced value of a mere 5.2 kcal mol−1 compared to the previously reported activation energies ranging from 20 to 30 kcal mol−1. Evidently, this significantly lowered barrier can be readily surpassed at typical room temperatures, exhibiting practical applicability. Notably, the alkali metal Na effectively serves as a catalyst, successfully diminishing the activation energy required for N2 production through the pyrolysis of pentazole compounds. This breakthrough discovery provides a theoretical basis for experimental research on the low-temperature cracking of pentazole compounds. It also offers valuable insights for the development and application of new high energy density materials, contributing to the creation of a green and low-carbon circular economic system. [ABSTRACT FROM AUTHOR]

Published
2024
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15. In situ molecule-level interface tailoring of metastable intermolecular composite chips toward on-demand heat release and information encryption.

Author

Guo, Xiaogang, Liang, Taotao, Tetteh, Ankamfio Julius, Islam, Md Labu, Huang, Huisheng, Yuan, Binfang, and Cui, Xun

Abstract

The ability to simultaneously tailor the on-demand heat release and in situ information encryption properties of high energy metastable intermolecular composites (MICs) to meet complex application environments represents an important endeavour toward advanced self-protected energetic materials. Herein, we report a simple yet efficient strategy for the construction of a multifunctional nano-Al/MnO2 MIC via a combined electrophoretic deposition and molecule-level interface tailoring approach. Notably, the orientation of the molecule lauryl-OSO3 can be adjusted through applying an electric field force and changing the affinity between polar molecules, thus achieving a wettability switch for MICs with uniform microstructure distribution and high purity. Interestingly, information encryption was demonstrated by constructing a hydrophilic–hydrophobic interface and two kinds of information encryption procedures were realized via superhydrophobization and superhydrophilization of the surface. More importantly, the highly controllable heat release properties of the product were demonstrated, largely contributing to the heat-release stability improvement (HRSI) and on-demand remote clearance or sheering properties (RC/SPs) of the product under changeable circumstances. This work provides a paradigm for the construction of a smart MIC chip and scientifically reveals the role of wettability in its heat release and information encryption capabilities, which may further broaden its potential application space. [ABSTRACT FROM AUTHOR]

Published
2023
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20. Mechanistic insights into the Cu(II)/DBU-catalyzed incorporation of CO2 into homopropargylic amines.

Author

Yuan, Binfang, Liu, Senmao, Liu, Tian, Li, Qing, Wang, Yulu, Guo, Zhihui, Guo, Xiaogang, Huang, Huisheng, and He, Rongxing

Subjects
*COPPER, *DENSITY functional theory, *AMINES, *ORGANIC bases, *CATALYTIC activity
Abstract

The mechanisms of Cu(II)/DBU-catalyzed carboxylation of homopropargylic amines with CO2 to construct 6-methylene-1,3-oxazin-2-ones are studied via density functional theory. The calculations suggest that Cu(II) catalysts exhibit a positive effect on the process of intramolecular cyclization, and the catalytic activities of which are determined by their coordination abilities ((DBU)CuCl2 < CuCl2 < [(DBU)CuCl]+). Furthermore, three roles of DBU are revealed in this study: (a) DBU acts as the proton-acceptor to capture a proton of homopropargylic amines. (b) DBU attacks CO2 to form DBU-CO2 as the nucleophilic agent, and then DBU-CO2 assists the H+ shift as the proton shuttle. (c) DBU serves as the ligand replacing one Cl− anion of CuCl2, forming the activated species [(DBU)CuCl]+. Besides, the theoretical study well explains the selectivity of Cu(II)-catalyzed reactions (6- vs. 7-membered cyclization), and the 6-membered products are found to be formed selectively. Overall, our work reproduces the experimental results well and provides an indispensable understanding of CO2-conversion to synthesize various high-value chemicals with the assistance of a catalytic system combining transition-metal catalysts and organic bases. [ABSTRACT FROM AUTHOR]

Published
2023
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28. Convenient design of anti-wetting nano-Al/WO3metastable intermolecular composites (MICs) with an enhanced exothermic life-span

Author

Guo, Xiaogang, Liang, Taotao, Guo, Junfeng, Huang, Huisheng, Kong, Shuying, Shi, Jianwei, Yuan, Binfang, and Sun, Qi

Abstract

For solving the dilemma of the short exothermic life-span of WO3based metastable interstitial composites (MICs) with extensive application prospect, this paper has firstly designed the promising anti-wetting Al/WO3MICs via electrophoresis assembly of nano-Al and WO3particles fabricated by hydrothermal synthesis method, followed by the subsequent fluorination treatment. A combination of X ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FT-IR) techniques were utilized in order to characterize the crystal structure, microstructure, and elemental composition distribution of target films after different natural exposure tests. The product with uniform distribution and high purity possesses a high contact angle of ∼170° and a minute sliding angle of ∼1°, and displays the outstanding anti-wetting property using droplets with different surface tensions. It also shows great moisture stability in high relative-humidity circumstances after one year of the natural exposure experiment. Notably, the heat output of a fresh sample can reach up to 2.3 kJ/g and retain 96% after the whole exposure test, showing outstanding thermo-stability for at least one year. This work further proposed the mechanism of anti-wetting Al/WO3MICs considering the variation tendency of their DSC curve, providing a valuable theoretical reference for designing other self-protected MICs with a long exothermic life-span applied in wide fields of national defense, military industry, etc.

Published
2023
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31. Conveniently controllable design of nano-Al-doped@Co3O4 energetic composite with enhanced exothermic property via exploring electrophoretic assembly dynamics.

Author

Guo, Xiaogang, Liang, Taotao, Liu, Guixiu, He, Yuanzhen, Kong, Shuying, Islam, Md. Labu, and Yuan, Binfang

Subjects
ELECTROPHORETIC deposition, PARTICLE dynamics, ACTIVATION energy, COMPOSITE materials, POLYETHYLENEIMINE, CRYSTALLINITY
Abstract

Achieving controllable film-forming process is always a difficult issue for practical application, especially for bi-/multiple component composite materials. Thus, this paper firstly developed a conveniently and controllable electrophoretic assembly technique under mild conditions to design nano-Al-doped@Co3O4 energetic film with wide potential applications. The stable suspension consists of isopropyl alcohol with the tracing of polyethylenimine and tween 80. The high crystallinity and uniformity of structure in target films were demonstrated by FESEM, EDX, XRD, and FT-IR techniques. Electrophoretic assembly dynamics of Al/Co3O4 particles were deeply explored to provide a theoretical foundation for optimizing exothermic performance. The exothermic performance of target film can be accurately adjusted, and the output of heat (Q) and activation energy (Ea) can reach up to ~ 3.6 kJ/g (close to 85% of theoretical value) and low to 230.01 kJ/mol, respectively. This breakthrough will substantially push forward the facile functional film-forming process of different kinds of particles used in fields of electronics, military, aviation, etc. [ABSTRACT FROM AUTHOR]

Published
2022
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