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Green Preparation of Ammonium Polyphosphate With shell-core structure for Enhancing Fire Safety of Thermoplastic Polyurethane

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POLYMERS FOR ADVANCED TECHNOLOGIES 2025年第1期36卷

作者： Duan, Jiahao Shi, Congling Yang, Ling Qian, Xiaodong Wan, Mei Zhu, Hongqing Wang, Houwang China Univ Min & Technol Beijing Sch Emergency Management & Safety Engn Beijing Peoples R China China Acad Safety Sci & Technol Beijing Key Lab Metro Fire & Passenger Transportat Beijing Peoples R China Capital Univ Econ & Business Sch Management Engn Beijing Peoples R China

In the recent years, the development of high-performance flame retardants (FRs) for thermoplastic polyurethane (TPU) has become increasingly important due to its wide applications in various industries and the growing demand for fire safety. In this study, ammonium polyphosphate (APP) was used as the core, whereas chitosan (CS) and nano-silica (SiO2) served as the shell to create a shell-core-structured FR through a self-assembly process in an aqueous phase. APP, APP@CS, and APP@CS@SiO2 were incorporated into TPU at a concentration of 20 wt%, and their effects on TPU properties were compared. The findings showed that APP@CS@SiO2 exhibited superior flame retardancy for TPU. Compared to pure TPU, the TPU/APP@CS@SiO2 showed reductions in peak heat release rate, total heat release, peak smoke production rate, total smoke production, peak CO production rate, and peak CO2 production rate by 58%, 80%, 80.5%, 89.1%, 20.4%, and 60.1%, respectively. Additionally, APP@CS@SiO2 effectively inhibited the thermal degradation of TPU and enhanced its thermal stability, resulting in the residual carbon content of the composite rising to 28.5%, which is about 20 times higher than that of pure TPU. In conclusion, APP@CS@SiO2 significantly improved the fire safety of TPU by efficiently catalyzing char formation in the condensed phase, diluting flammable gases, and hindering gas-phase free radical chain reactions, thereby opening new avenues for the practical application of TPU composites.

关键词： fire safety green preparation shell-core structure thermoplastic polyurethane

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Hydrophilic Ni(OH)2@CoB nano-chains with shell-core structure as an efficient catalyst for oxygen evolution reaction

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JOURNAL OF ALLOYS AND COMPOUNDS 2020年 844卷 156129-156129页

作者： Lu, Jun Ji, Shan Kannan, Palanisamy Wang, Hui Wang, Xuyun Wang, Rongfang Qingdao Univ Sci & Technol Coll Chem Engn State Key Lab Base Ecochem Engn Qingdao 266042 Peoples R China Jiaxing Univ Coll Biol Chem Sci & Chem Engn Jiaxing 314001 Peoples R China

Enormously active and cost-effective electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are the critical components to produce hydrogen via water splitting using the electricity produced from renewable energy sources. Herein, inspired by the highly electric conductivity of CoB, shell-core structured Ni(OH)(2)@CoB nano-chains are synthesized as highly active OER catalyst with the assistance of the magnetic field. In the shell-core structured Ni(OH)(2)@CoB nano-chains, Ni(OH)(2) nanoflakes were directly grown onto CoB nano-chains via a facile and wet chemical method. Ni(OH)(2) in nanoflake form can provide more available active sites on the surface for electrochemical reaction that is evidenced by high BET surface area (648.9 m(2) g-(1)). At the current density of 10 mA cm(-2), the over potentials of OER occurred on Ni(OH)(2)@CoB is 320 mV. The obtained Ni(OH)(2)@CoB also shows very good OER durability without any observable decline for 12 h. The high OER catalytic performance combined with its low-cost makes the Ni(OH)(2)@CoB nano-chains promising OER catalyst for water splitting in alkaline media. (c) 2020 Published by Elsevier B.V.

关键词： CoB Ni(OH)(2) shell-core structure Nano-chain Oxygen evolution reaction

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Hydrogel Fiber Actuators Prepared by shell-core structure for High‑Performance Water/Light Dual Response

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Advanced Fiber Materials 2024年第6期6卷 1887-1897页

作者： Qianqian Wang Linping Zhang Yi Zhong Hong Xu Zhiping Mao Key Lab of Science and Technology of Eco‑Textile Ministry of EducationCollege of Chemistry and Chemical EngineeringDonghua UniversityShanghai 201620China Shanghai Belt and Road Joint Laboratory of Textile Intelligent Manufacturing Innovation Center for Textile Science and TechnologyDonghua UniversityShanghai 201620China

Spiral fibers with high energy storage and high output efficiency are highly desirable for soft robots and ***,it is still a great challenge to achieve spiral fibers with excellent water actuation performance,structural stability,and high scalability in a low-cost strategy.A coaxial spiral structure is reported for the fabrication of high-performance fiber *** developed shell-core helical fiber actuators were based on alginate/poly(ethylene glycol)acrylate shell and alginate/GO core with green and excellent *** to the high water-absorbing-swelling capacity and energy storage of the shell,the prepared spiral fibers are characterized by fast response,high energy output,and good repeatability of *** the other hand,the core endows the spiral fibers with the additional features of strong force retention and photothermal *** shell-core spiral structure promotes the output efficiency of the twisted fiber actuator with a large rotation(2500°/cm),untwisting speed(2250 rpm),and recovery speed(2700 rpm).In addition,the tertiary spiral structure based on TAPG fibers exhibits excellent humidity and photothermal response *** application of fibers to smart textiles enables efficient human epidermal thermal management.

关键词： Hydrogel fibers shell-core structure Rapid response Large recovery speed Water/light dual response

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Enhancing creep resistance performance in silica-based ceramic core materials through shell-core structure

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JOURNAL OF THE EUROPEAN CERAMIC SOCIETY 2024年第14期44卷

作者： Chen, Xiao Lu, Gang Yan, Qingsong Gao, Peng Xu, Siming Tu, Zhixin Nanchang Hangkong Univ Sch Aeronaut Mfg Engn Natl Def Key Lab Light Alloy Proc Sci & Technol Nanchang 330063 Peoples R China

The creep behavior of silica-based ceramic cores significantly impacts dimensional precision in investment casting. This study focuses on synthesizing an alumina coating on fused silica surfaces to create a shell-core structure. The creep behavior of silica-based ceramic cores was explored. Specifically, the influence of the shell-core structure on their creep mechanism was investigated. The results revealed the excellent creep resistance of silica-based ceramic cores with shell-core structures. The softening deformation of particles and the viscous flow of the glass phase were observed to account for the differences in creep behavior. The alumina shell structure reinforced the powders, effectively inhibiting the softening deformation of the core structure. Notably, the shell-core structure not only suppressed the viscous flow of the glass phase, thereby weaking the pore filling process, but also promoted the mullitization reaction. This reaction accelerated the consumption of the glass phase, enhancing the creep resistance of the silica-based ceramic cores.

关键词： Silica-based ceramic core shell-core structure Creep behavior Pore filling process Mullitization

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Enhancing polymer fiber orientation with 3D-printed shell-core structures

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JOURNAL OF NON-NEWTONIAN FLUID MECHANICS 2025年 335卷

作者： Lou, Mengfan Ouyang, Zhenyu Ningbo Univ Minist Educ Lab Impact & Safety Engn Ningbo 315201 Peoples R China

This study numerically investigates the flow dynamics and fiber orientation in enhanced polymer shell-core structures during 3D printing using the smoothed particle hydrodynamics method. A microstructure-based fiber suspension model, coupled with a shear-thinning viscosity model, is employed to assess the effects of varying material viscosities, fiber aspect ratios and volume fractions, and substrate speeds on fiber orientation distribution. Our results demonstrate that fiber orientation in deposited layers is particularly sensitive to variations in the viscosity of the shell material, while changes in the core material viscosity have a smaller and more localized impact on fiber orientation. Furthermore, fiber orientation is strongly influenced by the product of the fiber aspect ratio alpha r and volume fraction phi;as alpha r phi increases, fibers tend to align with the flow direction of materials. However, adjusting the fiber aspect ratio and volume fraction while maintaining the same alpha r phi results in slight changes to fiber alignment. Additionally, lower substrate speeds cause upstream material accumulation, increasing deposition layer height and creating differences in fiber orientation between the core and shell regions. An appropriate increase in substrate speed can mitigate these effects.

关键词： Fused deposition modeling (FDM) Fiber orientation shell-core structure Smoothed particle hydrodynamics (SPH) method

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Polyethyleneimine modified Au core Rh shell nanodendrites for light-promoted nitrite reduction reaction at low concentration

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Journal of Energy Chemistry 2025年第4期103卷 400-407页

作者： Zhe Wang Xiaohui Wang Mengzhu Yun Xinyao Shi Xue Xiao Yan Liu Fan Yang Yucheng Jiang Yu Chen Key Laboratory of Macromolecular Science of Shaanxi Province School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi’an 710062ShaanxiChina School of Materials Science and Engineering Shaanxi Normal UniversityXi’an 710062ShaanxiChina Department of Public Security Northwest University of Political Science and LawXi’an 710122ShaanxiChina College of Chemistry and Materials Science Weinan Normal UniversityWeinan 714099ShaanxiChina

Ammonia(NH_(3))is a fundamental chemical in agriculture and an ideal hydrogen ***,NH_(3)synthesis strategies with high efficiency,energy conservation,environmental friendliness,and sustainability are desired *** nitrite(NO_(2)~-)reduction reaction(NO_(2-)RR)to NH_(3)offers a feasibly low-energy consumption and continuable approach to replace industrial NH_(3)***,polyethyleneimine(PEI)modified Au core Rh shell nanodendrites(Au@Rh-NDs)nanohybrid(Au@Rh-NDs/PEI)with branched structure is synthesized,which achieves the high NH_(3)yield(1.68 mg h^(-1)mg_(cat)^(-1))and Faradaic efficiency(FE)of 95.86%for NO_(2)~--RR at-0.39 V potential in neutral ***,the introduction of PEI significantly enhances the electroactivity of Au@Rh-NDs at low concentration of 1 mM NaNO_(2),which originates from the enrichment function of PEI for NO_(2)~-*** addition,the Au basement permits the sustainable solar power to expedite the NO_(2)~--RR at Au@Rh-NDs/PEI owing to the localized surface plasmon resonance(LSPR)of the Au core *** work may provide an admissible tactic to build excellent catalysts on account of organic molecule-mediated interfacial engineering in a variety of fields of catalysis and electrocatalysis.

关键词： Ammonia shell-core structure Interfacial engineering Nitrite reduction reaction Photothermal and photoelectric effect

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The Thermal Evolution Law of Meso-Microscaled Fe3C

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JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE 2025年 1-9页

作者： Liu, Qing-ru Gong, Zhen Xie, De-cong Liu, Yong-xing Miao, Hu-wei Wu, Fa-yu Jing, Wei-jun Univ Sci & Technol Liaoning Sch Mat & Met Anshan 114051 Peoples R China Tech Ctr Ben Gang Grp Corp Benxi 117000 Peoples R China Gansu Jiu Steel Grp Hongxing Iron & Steel Co Ltd Jiayuguan 735199 Gansu Peoples R China

Fe3C plays a crucial role in both structural and functional materials, particularly in the realms of steel manufacturing and carbon nanomaterial synthesis. This research focuses on investigating the thermal structure evolution of highly crystalline meso/microscaled pure phase Fe3C obtained by employing the electrochemical etching method. Various characterization techniques such as x-ray diffraction, micro-Raman spectroscopy system, synchronous thermal analyzer, Scanning Electron Microscope, and Transmission Electron Microscope were utilized to analyze the impact of annealing temperature and atmosphere on the thermal stability of Fe3C. The results show that: The decomposition of Fe3C into Fe and C occurs from the outside to the interior at 600 degrees C under oxygen-free conditions. A multi-chamber composite structure with a 20-30 nm amorphous carbon shell encapsulated Fe is formed. In such shell-core structures, residual Fe3C always persists, the compressive stress from the overall volume expansion, confined by the thick carbon shell, is responsible for that. Under oxygen-poor conditions, the meso-microscaled Fe3C can undergo the globally decomposition which results in the formation of a shell-core structure only at 500 degrees C. The introduction of oxygen etched the carbon shell with a more disordered structure. This structural disturbance releases internal stresses within the compound, facilitating the continuous decomposition of Fe3C, ultimately leading to the formation of nanoscaled particles comprising carbon-encapsulated iron and iron oxide.

关键词： decomposition mechanism Fe3C shell-core structure thermal stability

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Formation mechanism of silicone rubber particles with core-shell structure by seeded emulsion polymerization

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JOURNAL OF APPLIED POLYMER SCIENCE 1996年第2期61卷 383-388页

作者： He, WD Cao, CT CaiYuan, P UNIV SCI & TECHNOL CHINA DEPT MAT SCI & ENGNHEFEI 230026ANHUIPEOPLES R CHINA

Silicone rubber particles with core-shell structure were prepared by polymerization of vinyl monomers in the presence of crosslinked and linear poly(dimethyl siloxane-methyl vinyl siloxane) latex. The monomers were added with either continuous or swelled-continuous addition mode. The core-shell morphology of silicone rubber/polystyrene [PST] and silicone rubber/poly(methyl methacrylate-divinyl benzene) [P(MMA-DVB)] composite particles were obtained. The effects of monomer addition mode, the compatibilities of the monomers or their homopolymer with silicone rubber, and the reactivity of polysiloxane with vinyl monomers on the formation of the core-shell structure were discussed. (C) 1996 John Wiley & Sons, Inc.

关键词： Homopolymers shell structures Silicone rubber polysiloxanes core-shell shell-core structure monomers VINYL MONOMERS Siloxanes particles EMULSION POLYMERISATION

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Synthesis and catalysis of polymer-protected Pd/Ag/Rh trimetallic nanoparticles with a core-shell structure

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BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007年第6期80卷 1217-1225页

作者： Matsushita, Torn Shiraishi, Yukihide Horiuchi, Shin Toshima, Naoki Tokyo Univ Sci Dept Mat Sci & Environm Engn Yamaguchi 7560884 Japan Tokyo Univ Sci Grad Sch Sci & Engn Yamaguchi 7560884 Japan Tokyo Univ Sci Adv Mat Inst Yamaguchi 7560884 Japan Natl Inst Adv Ind Sci & Technol Nanotechnol Res Inst Nanosci Measurements Grp Tsukuba Ibaraki 3058562 Japan

Colloidal dispersions of polymer-protected Pd/Ag/Rh trimetallic nanoparticles were synthesized via self-organization by mixing colloidal dispersions of polymer-protected Rh nanoparticles with those of polymer-protected Pd/Ag bimetallic nanoparticles with a core-shell (Pd-core/Ag-shell) structure, which were prepared in advance by a sacrificial hydrogen-reduction method. The Pd/Ag/Rh trimetallic nanoparticles appeared to have a triple core-shell (Pd-core/ Ag-interlayer/Rh-shell) structure on the basis of UV-vis absorption spectra, FT-IR spectra of adsorbed CO, TEM, HR-TEM, and EF-TEM observation. The spontaneously formed trimetallic nanoparticles having an atomic composition of Pd/Ag/Rh = 1/2/13.5 and an average diameter of 2.2 nm showed the highest catalytic activity among the metal nanoparticle catalysts tested here for hydrogenation of methyl acrylate at 30 degrees C under atmosphere of hydrogen.

关键词： shell structures energy filtered transmission electron microscopy advance shell-core structure mean diameter Metal Nanoparticles COLLOIDAL DISPERSIONS Nanoparticles methyl acrylate synthesis atmosphere Catalysis Catalyst activity Hydrogenation

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core-shell structure BaFe12O19@PANI composites with thin matching thickness and effective microwave absorption properties

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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS 2019年第15期30卷 14344-14354页

作者： Wang, Mengqi Lin, Ying Liu, Yiran Yang, Haibo Shaanxi Univ Sci & Technol Shaanxi Key Lab Green Preparat & Functionalizat I Sch Mat Sci & Engn Xian 710021 Shaanxi Peoples R China

The BaFe12O19@PANI composites with different polyaniline (PANI) contents were successfully synthesized by an in situ polymerization method. The composition, phase and morphologies of these composites were characterized thoroughly. The result shows that the introduction of PANI can effectively the absorbing properties of barium ferrite. The prepared BaFe12O19@PANI composites had the best absorption performance when the amount of aniline addition was 400 mu l with the reflection loss of - 65.354 dB, and the matching thickness is 1.47 mm. The introduction of PANI can decrease the weight of electromagnetic absorbing materials, and enhance the dielectric loss and the degree of polarization of the interface. The effective microwave absorption characteristics with thin thickness make the BaFe12O19@PANI composites have great potential application.

关键词： Absorption (physics) microwave absorption Reflection loss Polarization Composites shell-core structure Dielectric losses Absorptive properties

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