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1.
Dalton Trans ; 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38980718

ABSTRACT

Energetic Metal-Organic Framework (EMOF) compounds have gained significant attention in recent years as a hot research topic in the fields of explosives and propellants. This article provides an overview of the latest research progress of EMOFs in various areas, including heat-resistant explosives, burning rate catalysts and initiating explosives. It discusses the recent development trends of high-energy EMOFs, such as high-dimensional and solvent-free structural design, simplified and scalable synthesis conditions, environmentally friendly manufacturing processes with tunable structures, high-energy, low-sensitivity and multifunctional target products. The challenges and issues faced by EMOFs in heat-resistant explosives, burning rate catalysts and initiating explosives are presented. Furthermore, the key research directions for future applications of EMOFs in the fields of explosives and propellants are discussed, including solvent-free high-dimensional EMOFs design and synthesis, precise modulation of EMOFs molecular composition and pore structure, improvement of accurate prediction methods for physicochemical properties of high-energy EMOFs, low-cost large-scale production and development of multifunctional composite EMOFs as energetic materials, exploration of influencing factors, and comprehensive study on the application of novel and high-performance multifunctional EMOFs.

2.
Front Chem ; 10: 1032163, 2022.
Article in English | MEDLINE | ID: mdl-36311438

ABSTRACT

Energetic Metal Organic Frameworks (EMOFs) have been a hotspot of research on solid propellants in recent years. In this paper, research on the application of EMOFs-based burning rate catalysts in solid propellants was reviewed and the development trend of these catalysts was explored. The catalysts analyzed included monometallic organic frameworks-based energetic burning rate catalysts, bimetallic multifunctional energetic burning rate catalysts, carbon-supported EMOFs burning rate catalysts, and catalysts that can be used in conjunction with EMOFs. The review suggest that monometallic organic frameworks-based burning rate catalysts have relatively simple catalytic effects, and adding metal salts can improve their catalytic effect. Bimetallic multifunctional energetic burning rate catalysts have excellent catalytic performance and the potential for broad application. The investigation of carbon-supported EMOFs burning rate catalysts is still at a preliminary stage, but their preparation and application have become a research focus in the burning rate catalyst field. The application of catalysts that can be compounded with EMOFs should be promoted. Finally, environmental protection, high energy and low sensitivity, nanometerization, multifunctional compounding and solvent-free are proposed as key directions of future research. This study aims to provide a reference for the application of energetic organic burning rate catalysts in solid propellants.

3.
Polymers (Basel) ; 14(16)2022 Aug 16.
Article in English | MEDLINE | ID: mdl-36015589

ABSTRACT

A Diels-Alder (DA) bond containing poly(tetrahydrofuran)-co-(ethyleneoxide) (PET) based linear polyurethane (PET-DA-PU) was synthesized via a prepolymer process using PET as raw material, DA diol as chain extender agent, and toluene-2,4-diisocyanate (TDI) as coupling agent. The structure of PET-DA-PU was characterized by attenuated total reflectance-Fourier transform-infrared spectroscopy (ATR-FTIR), proton nuclear magnetic resonance spectrometry (1H NMR) and carbon nuclear magnetic resonance spectrometry (13C NMR). The thermal performance and self-healing behavior of PET-DA-PU were investigated by differential scanning calorimetry (DSC), polarized optical microscope, universal testing machine, scanning electron microscopy (SEM) and NMR, respectively. The glass transition temperature of PET-DA-PU was found to be -59 °C. Under the heat treatment at 100 °C, the crack on PET-DA-PU film completely disappeared in 9 min, and the self-healing efficiency that was determined by the recovery of the largest tensile strength after being damaged and healed at 100 °C for 20 min can reach 89.1%. SEM images revealed the micro-cracks along with the blocky aggregated hard segments which were the important reasons for fracture. NMR spectroscopy indicated that the efficiency of retro DA reaction of PET-DA-PU was 70% after 20 min heating treatment at 100 °C. Moreover, the PET-DA-PU/Al/Na2SO4 composite was also prepared to simulate propellant formulation and investigated by universal testing machine and SEM; its healing efficiency was up to 87.8% under the same heat treatment process and exhibits good self-healing ability. Therefore, PET-DA-PU may serve as a promising thermally self-healing polymeric binder for future propellant formulations.

4.
Macromol Rapid Commun ; 42(2): e2000504, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33210372

ABSTRACT

Herein, efficient fabrication of polymersomes that have unique and nonequilibrium morphologies is reported. Starting from preparing big polymeric vesicles sized around 2 µm with a flexible but crosslinkable structure, a controllable morphological transformation process from the vesicles via prolate vesicles and the pearl-chain-like structure, which are the two intermediate structures, to vesicle-end-capped tubes is conducted. Significantly, each of the intermediates is a regular polymersome and occupies a distinct phase space in the transformation process and thus can be separately processed and prepared. By crosslinking the structures, respectively, regular polymersomes with unique but stable morphologies are fabricated. Furthermore, the 1D polymersomes contain narrow necks. These narrow necks are sensitive to ultrasound vibration and broken by gentle ultrasound treatment to form regular open-ended tubes and open-ended vesicles, which are nonequilibrium but stable morphologies and difficult to prepare by existing methods.


Subject(s)
Polymers
5.
Chem Commun (Camb) ; 56(99): 15553-15556, 2020 Dec 25.
Article in English | MEDLINE | ID: mdl-33242060

ABSTRACT

Sparsely modified surfaces can be used as a general platform for precisely modifying small nanoparticles. However, strictly, rather than statistically, sparse surface modification remains a big challenge. Herein, we report a new and general method for strictly sparse modification of the surface of relatively large nanoparticles. The method is analogous to planting big trees and then removing the big crowns, leaving the stumps on the ground; due to the large exclusive size of the crowns, the stumps are strictly sparsely distributed. As a proof of concept, strictly sparse modification of surfaces was demonstrated by the successful preparation of "monovalent" and "divalent" golden nanoparticles (AuNPs) with different sizes. Starting from the "monovalent" and "divalent" AuNPs, AuNP dimers and chain-like AuNP assemblies were prepared, respectively.

6.
ACS Macro Lett ; 7(11): 1278-1282, 2018 Nov 20.
Article in English | MEDLINE | ID: mdl-35651249

ABSTRACT

We report the first example of the fabrication of pure, single-chain Janus particles (SCJPs). The SCJPs were prepared by double-cross-linking an A-b-B diblock copolymer in a common solvent. Inevitably, the double-cross-linking led to a mixture containing not only SCJPs but also multichain particles and irregular single-chain particles. Under well-controlled conditions, the SCJPs in the mixture self-assemble with high exclusivity to form regularly structured macroscopic assemblies (MAs) with a crystal-like appearance that precipitate from the suspension. Pure SCJPs that are uniform in size, shape and Janus structure were efficiently prepared by collection and dissociation of the MAs. Block copolymers with different structural parameters were successfully used for the exclusive self-assembly (ESA), and pure SCJPs with varied structural parameters were produced, confirming the reliability of the ESA method.

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