RSC Advances
·
2017
·Vol. 7
·期 61
·38691-38698
·
IF 3.108
Bin Li,Wubin Wu,Tianyong Zhang,Shuang Jiang,Xingwei Chen,Guanghui Zhang,Xia Zhang
UiO-66 with high dispersibility and a cuboctahedron morphology was synthesized by an improved solvothermal method. The morphology of UiO-66 was adjusted using benzoic acid as a modulator. UiO-66 with a regular morphology was then used as the support to load ferrocene (Fc). A series of Fc@UiO-66 composites were prepared via a facile impregnation method. The composites were characterized by powder X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), SEM/EDX mapping, FT-IR, UV/vis, TG analysis, N2 adsorption–desorption, and X-ray photoelectron spectroscopy (XPS). The results showed that Fc was incorporated into UiO-66, thus preventing the agglomeration of Fc particles in water. The Fc@UiO-66 composites with a Fc loading of 5% (FU-5) exhibited the highest catalytic activity for hydroxylation of phenol with H2O2 at room temperature in water, which gave a phenol conversion of 38.5% and 87.4% selectivity for dihydroxybenzenes (DHB). UiO-66 played a crucial role in the enhancement of catalytic performance compared with conventional supports such as γ-Al2O3, etc. A hydroxyl radical mechanism was proposed for this catalytic hydroxylation process and the high selectivity was attributed to the interaction between Fc particles and UiO-66.
研究领域:
化学
·
催化材料科学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 21
·52209
·
IF 3.057
Yong Guo,Zhongwei Chen,Yuan Yu,Tingting Chen,Qingwu Zhang,Changxin Li,Juncheng Jiang
A new-type flame retardant DEZ of bi-DOPO compound containing bi-hydroxy and two amino groups, was synthesized from terephthalonitrile, hydroxylamine hydrochloride, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and used with curing agent 4,4′-diamino-diphenylmethane to prepare flame retard epoxy resin (EP) composites. 1 H and 31 P nuclear magnetic resonance spectra and Fourier transform infrared spectra have determined the chemical structure of DEZ. The properties of cured EP composites were explicitly evaluated by differential scanning calorimeter, thermogravimetric analysis, the limiting oxygen index (LOI), vertical burning (UL-94) test, cone calorimetry test, and flexural test. The 1 wt% addition of DEZ could improve the EP composites by almost 14.4% of flexural strength and 29.6% of flexural modulus, respectively. The LOI of EP composites with 5 wt% of DEZ was 29.7% and EP composites reached a V-0 rating in the UL-94 test, as well as total heat release was decreased by 11.2%. All EP modified by DEZ exhibited a blow-out effect in the combustion process, which was due to the release of pyrolysis gases and incombustible gases containing phosphorus radicals and nitrogen compounds.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 14
·50165
·
IF 2.52
Junjun Zhang,Huajun Duan,Jianfan Cao,Jiahao Zou,Huiru Ma
A high-efficiency DOPO-based reactive flame retardant (DPE) with bi-hydroxyl was successfully synthesized via reacting DOPO with imine obtained from the condensation of ethanolamine and 1,4-phthalaldehyde, and used as co-curing agent to improve the fire safety of epoxy resin (EP). Its chemical structure was characterized by Fourier transform infrared (FTIR) spectra, 1 H, 31 P nuclear magnetic resonance (NMR) spectra and elemental analysis. The curing behavior, thermal properties, flame-retardant properties of EP/DPE systems were investigated. The results revealed that DPE slightly decreased the glass transition temperature ( T g ), but accelerated the curing cross-linking reaction of EP. Furthermore, DPE decreased thermal degradation rate of epoxy matrix and promoted the formation of residual char at high temperature. After adding DPE, the flame retardant of epoxy thermosets was greatly improved. Especially, the thermoset modified with 5 wt% DPE achieved limiting oxygen index (LOI) value of 33.6% and V-0 rating in UL-94 test, demonstrating the highly efficient flame retardancy. While its peak heat release rate (PHRR), total heat release (THR) and total smoke production (TSP) were respectively decreased by 32.6%, 17.8%, and 13.9% compared with neat EP. Moreover, the research on flame retardant mechanism disclosed that DPE played dual flame-retardant effect in the gaseous and condensed phases.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
Nanoscale
·
2015
·Vol. 7
·期 40
·16737-16743
·
IF 7.394
Zhixiong Li,Ruizheng Liang,Wendi Liu,Dongpeng Yan,Min Wei
Stimuli-responsive fluorescent switches have shown broad applications in optical devices, biological materials and intelligent responses. Herein, we describe the design and fabrication of a dual-stimuli-responsive fluorescent switch ultrathin film (UTF) via a three-step layer-by-layer (LBL) technique: (i) encapsulation of spiropyran (SP) within an amphiphilic block copolymer (PTBEM) to give the (SP@PTBEM) micelle; (ii) the mixture of riboflavin (Rf) and poly(styrene 4-sulfonate) (PSS) to enhance the adhesion ability of small molecules; (iii) assembly of negatively charged SP@PTBEM and Rf–PSS with cationic layered double hydroxide (LDH) nanoplatelets to obtain the (Rf–PSS/LDH/SP@PTBEM)n UTFs (n: bilayer number). The assembly process of the UTFs and their luminescence properties, as monitored by fluorescence spectroscopy and scanning electron microscopy (SEM), present a uniform and ordered layered structure with stepwise growth. The resulting Rf–PSS/LDH/SP@PTBEM UTF serves as a three-state switchable multicolor (green, yellow, and red) luminescent system based on stimulation from UV/Vis light and pH, with an acceptable reversibility. Therefore, this work provides a facile way to fabricate stimuli-responsive solid-state film switches with tunable-color luminescence, which have potential applications in the areas of displays, sensors, and rewritable optical memory and fluorescent logic devices.
研究领域:
材料科学
·
光学
·
生物材料
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产品关联
DOI
PubMed
高影响因子
Materials
·
2023
·Vol. 16
·期 4
·1643
·
IF 3.4
Yihan Guo,Tongxiang Chen,Yongjin Zou
In this study, MXene-derived/NiCoFe-LDH heterostructures with three-dimensional interconnected porous network microstructures were prepared, leveraging the excellent electrical conductivity and growth platform provided by the MXene material. The remarkable specific capacitance of metal oxides was fully exploited. The composite exhibited high specific capacitance and excellent stability, with a specific capacitance of 1305 F g−1at 1 A g−1and a capacitance of 85.7% of the initial performance after 6000 charge/discharge tests at 10 A g−1. A two-electrode assembly was constructed using activated carbon as the negative electrode material corresponding to 49.5 Wh kg−1at 800 W kg−1, indicating that the electrodes could achieve rapid charge/discharge. The findings of this study indicate that the composite material comprising LDH/MXene has significant potential for supercapacitor applications.Keywords:supercapacitor;MXene;layered double hydroxide;three-dimensional
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Jiachen Zhu,Lijuan Li,Lianmin Ji,Shengjie Lan,Shaojie Tao,Donghai Zhu
The preparation of high-performance epoxy resins (EP) with enhanced mechanical properties and flame retardancy for building materials has long been a significant challenge. In this study, bio-based phytic acid (PA) was intercalated into the layers of layered double hydroxides (LDH) via coprecipitation. Subsequently, ultrafine Fe(OH) 3 was in situ grown on PA-intercalated LDH through tannin-mediated assembly, resulting in the synthesis of the LDH-PA@TA-Fe(OH) 3 hierarchical hybrid flame retardant. Comprehensive characterization of its microstructure, morphology, and chemical composition was performed. The EP composite demonstrated a LOI of 31.3 % and a UL-94 V-1 rating when the additive of 7.5 wt% LDH-PA@TA-Fe(OH) 3 was utilized. Additionally, the EP/LDH-PA@TA-Fe(OH) 3 composite demonstrated a substantial reduction in peak heat release rate (pHRR) and peak smoke production rate (pSPR) with reductions of 48.1 % and 52.7 %, respectively, along with a 62.5 % decrease in peak CO production rate (pCOP), compared to neat EP. These improvements in fire safety are primarily ascribed to the synergistic flame retardancy of LDH and Fe(OH) 3 in condensed and gas phases, along with the efficient catalytic charring performance of PA and Fe 3+ . Furthermore, the incorporation of LDH-PA@TA-Fe(OH) 3 enhanced the mechanical properties of EP, which could be ascribed to the improved dispersibility of the modified LDH and the strengthened interfacial interaction. This study introduces a novel approach for the development of highly effective LDH-based hybrid flame retardant materials, enabling the fabrication of EP composites with superior mechanical performance and fire safety.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Xinyu Lu,Xiaoli Gu
In this study, lignin-based epoxy resins (EP) were fabricated using lignin, phenol and glyoxal as crosslinking reagents. For improving the flame retardancy, a bi-DOPO compound with bi-hydroxyl structure was successfully synthesized, containing excellent quenching and charring capacities. Good pyrolysis behaviors of as-synthesized flame retardant resulted in significant quenching effect via structure decomposition to release PO and PO 2 free radicals for capturing reactive H and OH radicals produced from epoxy combustion. With addition of 0.18 wt% phosphorus, epoxy composite (10% LPG-ER-4) passed V-0 rating with high limited oxygen index (LOI) value of 35.2%. Cone calorimeter tests showed that heat release (including heat release rate (HRR) and total heat release (THR)) from combustion was reduced with assistance of flame retardant. Char residue analyses illustrated that bi-hydroxyl structure in DOPO-based flame retardant benefited the formation of char layer with higher compactness and integrity to serve as a protective shell of interior epoxy matrix. Furthermore, exterior pore size of char residue was narrowed or blocked to avoid the release of heat and volatiles generated from combustion. This study provided a feasible method to improve flame retardancy of lignin-based EP and proposed flame-retardant mechanism both in gaseous and solid phases.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Jinsheng Duan,Yilin Li,Zhaogang Liu,Peijie Jia,Junchang Fan,Yanhong Hu,Feng Guo,Jinxiu Wu
This study investigates the impact of layered double hydroxides (LDHs) intercalated with various ions on the thermal degradation and stability of polyvinyl chloride (PVC). Three types of LDHs—carbonate LDHs (C-LDHs), diphenyl phosphate LDHs (P-LDHs), and sarcosine LDHs (N-LDHs)—were synthesized using co-precipitation and hydrothermal methods. Thermogravimetric analysis (TGA) revealed that C-LDHs significantly enhanced the thermal stability of PVC, increasing the activation energy during early degradation phases by up to 25% compared to pure PVC. N-LDHs also improved stability, particularly at higher temperatures, with activation energy rising by 18% in the later stages. P-LDHs, however, showed the least stabilization effect, with a 10% lower activation energy compared to pure PVC. The degradation process of PVC in the presence of LDHs was analyzed using model-free methods, which revealed the complex multistep nature of PVC degradation. Reaction mechanisms were predicted using the generalized master plot method, identifying distinct stages of thermal degradation. Overall, C-LDHs were found to be the most effective at retarding PVC thermal degradation, suggesting their potential as advanced eco-friendly stabilizers. The use of model-free methods and reaction mechanism analysis offers new insights into the design of more efficient thermal stabilizers for polymers.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Xinqiang Zhu,Yatao Wu,Yingzhuo Lu,Yangyi Sun,Qiang Wu,Yajun Pang,Zhehong Shen,Hao Chen
The unsatisfactory cycle life of nickel-based cathodes hinders the widespread commercial usage of nickel–zinc (Ni–Zn) batteries. The most frequently used methods to improve the cycle life of Ni-based cathodes are usually complicated and/or involve using organic solvents and high energy consumption. A facile process based on the hydrolysis-induced exchange of the cobalt-based metal-organic framework (Co-MOF) was developed to prepare aluminum (Al)-doped cobalt–nickel double hydroxides (Al-CoNiDH) on a carbon cloth (CC). The entire synthesis process is highly efficient, energy-saving, and has a low negative impact on the environment. Compared to undoped cobalt–nickel double hydroxide (Al-CoNiDH-0%), the as-prepared Al-CoNiDH as the electrode material displays a remarkably improved cycling stability because the Al-doping successfully depresses the transition in the crystal phase and microstructure during the long cycling. Benefiting from the improved performance of the optimal Al-CoNiDH electrode (Al-CoNiDH-5% electrode), the as-constructed aqueous Ni–Zn battery with Al-CoNiDH-5% as the cathode (Al-CoNiDH-5%//Zn) displays more than 14% improvement in the cycle life relative to the Al-CoNiDH-0%//Zn battery. Moreover, this Al-CoNiDH-5%//Zn battery achieves a high specific capacity (264 mAh g −1 ), good rate capability (72.4% retention at a 30-fold higher current), high electrochemical energy conversion efficiency, superior fast-charging ability, and strong capability of reversible switching between fast charging and slow charging. Furthermore, the as-assembled quasi-solid-state Al-CoNiDH-5%//Zn battery exhibits a decent electrochemical performance and satisfactory flexibility.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Yan Sang,Zixuan Guo,Guohong Li,Yingying Xue,Jingwei Xue
The study and development of bifunctional non-precious metal catalysts with excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) electrocatalytic activities are particularly important and challenging for electrocatalytic total water splitting. Here, we report a non-precious material constructed by growing cobalt-nickel double hydroxides on ZIF-derived Co nanoparticles and nitrogen-doped carbon framework (CoNi-LDH/Co@NC), which exhibits excellent electrocatalytic performances for both OER and HER in alkaline media. When used as OER and HER electrocatalysts, CoNi-LDH/Co@NC only needs 359 mV and 187 mV overpotentials at a current density of 100 mA cm −2 , respectively. Surprisingly, using CoNi-LDH/Co@NC as both cathode and anode for a two-electrode water splitting system, a small battery voltage of 1.51 V is required at the current density of 10 mA cm −2 , and the current density remained stable for 20 h without any obvious attenuation. This opens up new possibilities for further exploration of non-precious metal electrocatalysts for water splitting.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF VINYL & ADDITIVE TECHNOLOGY
·
2023
·Vol. 30
·期 1
·313-325
·
IF 2.7
Baoming Xu,Jingxue Yang,Xinhui Wang,Na Wang,Guorong Chen,Heng Zhang
In this paper, we report on the synthesis of a new aluminum bis(hydroxy-phenyl-methyl)phosphinate, AlBPi, under mild reaction conditions. The product structure was confirmed via characterization, and its thermal stability and flame retardant properties were assessed. To improve the flame retardant properties, we employed ammonium polyphosphate (APP) as a synergist with AlBPi. The PLA composite material containing 10% AlBPi and 5% APP achieved an LOI of 28.1% and a UL-94 rating of V-1. Cone calorimetry tests showed a significant reduction in PHRR, THR, PSPR, and TSP for the PLA/AlBPi/APP composite compared to the pure and PLA/AlBPi materials. SEM analysis revealed a continuous and dense char layer on the residual surface of the synergistic flame retardant sample. AlBPi and APP exhibited excellent synergistic flame retardant effects, with both releasing a large amount of PO·free radicals. APP was also able to release inert gas, exhibiting excellent flame retardant effects in the gas phase. Additionally, APP improved the charring performance of AlBPi and formed a compact char layer on the material surface, achieving good flame retardant effects in the condensed phase. Therefore, the AlBPi and APP synergistic flame retardant system can be considered a viable flame retardant additive for PLA. Highlights A novel flame retardant AlBPi was synthesized. AlBPi and APP demonstrate good synergistic flame retardant performance in PLA. AlBPi and APP play a flame retardant role in both gas and condensed phases.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2024
·
IF 5.3
Xinying Su,Weihong Chai,Ziyang Zhang,Zhenlin Tang,Meihuan Gao,Yingge Li,Zhishuang Han,Xinmeng Lv,Jing He,Haidi Li,Zaihang Zheng
Aimed at settling the adverse effect of halogen−/phosphorus-containing flame retardants on the human health and ecological environment, a hydromagnesite (HM)-based flame retardant was prepared via sequential modification of polydopamine (PDA) and layered double hydroxide (LDH), which was expected to enhance the flame retardancy of silicone rubber (SR). The preparation feasibility for HM@PDA@LDH were confirmed by a series of characterizations in view of chemical composition, surface morphology, wettability and thermal degradation. The flame retardancy of 20 parts of HM@PDA@LDH per one hundred of silicone rubber (SR/20 phr HM@PDA@LDH) was upgraded with limiting oxygen index (LOI) of 30.5 %, Underwriters Laboratories-1894 Vertical burning-0 (UL-94 V-0) rating and peak heat release rate (PHRR) reduction of 59.6 % in comparison with neat SR. Besides, the possible mechanism was proposed by investigating the combustion residues of SR composites. Along with durable flame retardancy and maintained mechanical strength, the good balance among comprehensive properties of SR composites was gained. Thus, this paper proposed a valuable strategy for overcoming the contradiction between flame retardancy and environmental pollution, which was feasible for the real-world application of SR materials.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）