JOURNAL OF ALLOYS AND COMPOUNDS
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2019
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IF 4.175
Chao Xu,Xuetong Zhao,Lulu Ren,Jianjie Sun,Lijun Yang,Jing Guo,Ruijin Liao
Highly dense CaCu 3 Ti 4 O 12 (CCTO) ceramics co-doped by ZnO and Al 2 O 3 were synthesized by spark plasma sintering (SPS) at 750 °C for 10 min, and then annealed at 1000 °C for 3 h. The homogeneous microstructures were achieved, and the grain size was suppressed to around 2 μm. Dramatically enhanced electrical properties of CCTO ceramics were obtained when 1 mol% ZnO and Al 2 O 3 were co-doped. The breakdown field was improved to 12.13 kV/cm and the nonlinear coefficient was increased to 6.59, accompanying with a low dielectric loss of 0.02 at around 1 kHz, which were ascribed to the elevation of Schottky barrier height from 0.54 eV to 0.80 eV. Comparing with the pure CCTO sample, the activation energy of grain boundary obtained from the impedance spectra increases from 0.64 eV to 0.92 eV. Additionally, the grain and grain boundary resistance were also discussed based on the Cole-Cole plot, from which the grain boundary resistance was found to be increased significantly from 3.8 × 10 5 Ω to 4.0 × 10 6 Ω after co-doping.
研究领域:
材料科学
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陶瓷
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电气工程
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固体物理
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高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2022
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IF 3.656
Chunfu Liu,Chenyu Zhu,Han Wang,Shenao Xie,Junyang Zhou,Hongjun Fang
Co-doped metal organic frameworks (MOFs) were fabricated by a facile route and applied to remove (tetracycline, congo red, methylene blue and rhodamine B) through integrated adsorption and photocatalysis . The assembled MOFs composite exhibited larger S BET (889 m 2 /g), broad light adsorption, and accelerated carrier kinetics, which helped to enhance adsorption and photocatalysis performance. Specifically, nearly 100% TC (40 mg/L) could be removed by the Co-MIL-10 within 12 min solar-light irradiation, significantly faster than that of solo MIL-53(Al) (82%) and CoAl-LDH (54%), separately. Furthermore the obtained rate constant (0.2064 min −1 ) was 4.8 times and 9.7 times greater than that of MIL-53(Al) and CoAl-LDH, respectively. The quenching/EPR characterization suggested that photo-generated h + / • O 2 − / • OH species were responsible for TC oxidation , of which h + showed the great impact. Cycling experiments verified the robust stability of the MOFs catalyst. As well, an underlying photocatalytic mechanism of the current system was investigated in detail.
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POLYMERS FOR ADVANCED TECHNOLOGIES
·
2022
·Vol. 33
·期 12
·4290-4301
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IF 3.348
Ping Lyu,Yongbo Hou,Rongzhen Wang,Mingliang Ma,Yan Chen,Qiyang Xing,Yong Ma,Shuang Wang,Yuefeng Wu,Weibo Huang
The flame retardant zinc ferrite@Mg-Al-sodium dodecyl benzene sulfonate layered double hydroxide (ZnFe 2 O 4 @Mg-Al-SDBS LDH) was prepared successfully by simple hydrothermal method and co-precipitation method. ZnFe 2 O 4 nanoparticle was used as the core on which Mg-Al LDH was encapsulated to form a spherical structure with a lamellar intercalation layer. The microstructure, the phase structure, and the thermal properties of flame retardant were characterized in detail. Compared with pure polyurea (PUA), the total heat release (THR), peak heat release rate (PHRR) and smoke factor (SF) of PUA/ZnFe 2 O 4 @Mg-Al-SDBS LDH 3.0 wt% decreased by 17.64%, 20.13%, and 28.42%, respectively. In the combustion process, Mg-Al LDH could generate porous metal oxides (Al 2 O 3 and MgO), and ZnFe 2 O 4 could also be decomposed into ZnO and Fe 2 O 3 . These oxides catalyzed cross-linking of polymer molecules, to promote the formation of a dense char layer, and isolated heat and combustible gases from the underlying material. The improved flame retardant properties of the modified intercalated microspheres could be attributed to catalytic carbonization and physical barrier. Moreover, the mechanical properties of PUA composites were tested by universal tensile testing machine. The results showed that the addition of ZF@MASL flame retardant had little influence on the mechanical properties of PUA composites.
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ENVIRONMENTAL RESEARCH
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2022
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IF 8.431
Luan Minh Nguyen,Ngoan Thi Thao Nguyen,Thuy Thi Thanh Nguyen,Dai Hai Nguyen,Duyen Thi Cam Nguyen,Thuan Van Tran
The global occurrence of textile dyes pollution has recently emerged, posing a serious threat to ecological systems. To abate dye contamination, we here developed a novel magnetic porous CoFe 2 O 4 @MIL–53(Al) nanocomposite by incorporating magnetic CoFe 2 O 4 nanoparticles with MIL–53(Al) metal–organic framework. This nanocomposite possessed a surface area of 197.144 m 2 g −1 and a pore volume of 0.413 cm 3 g −1 . The effect of contact time (5–120 min), concentration (5–50 mg L −1 ), dosage (0.1–1.0 g L −1 ), and pH (2–10) on Congo red adsorption was clarified. CoFe 2 O 4 @MIL–53(Al) could remove 95.85% of Cong red dye from water with an accelerated kinetic rate of 0.6544 min −1 within 10 min. The kinetic and isotherm models showed the predominance of Bangham and Temkin. According to Langmuir, the maximum uptake capacities of CoFe 2 O 4 @MIL–53(Al), CoFe 2 O 4 , and MIL–53(Al) adsorbents were 43.768, 17.982, and 15.295 mg g −1 , respectively. CoFe 2 O 4 @MIL–53(Al) was selected to optimize Cong red treatment using Box–Behnken experimental design. The outcomes showed that CoFe 2 O 4 @MIL–53(Al) achieved the highest experimental uptake capacity of 35.919 mg g −1 at concentration (29.966 mg L −1 ), time (14.926 min), and dosage (0.486 g L −1 ). CoFe 2 O 4 @MIL–53(Al) could treat dye mixture (methylene blue, methyl orange, Congo red, malachite green, and crystal violet) with an outstanding removal efficiency of 81.24% for 30 min, and could be reused up to five cycles. Therefore, novel recyclable and stable CoFe 2 O 4 @MIL–53(Al) is recommended to integrate well with real dye treatments systems.
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PubMed
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2023
·Vol. 148
·期 11
·4731-4743
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IF 4.4
Kang Furu,Deng Jun,Pang Qingtao,Yuan Chao,Liu Bo,Yi Xin,Li Hang
Silicone foams (SiFs) are high-performance materials but can combust and release choking smoke in a fire. In this paper, the modified microencapsulated Mg/Zn/Al-layered double hydroxide (MLDHs) was prepared by the sol–gel method. Then, the structure and performance of modified MLDHs were characterized by field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TG), and differential scanning calorimetry (DSC). Besides, the mechanical properties, flame retardancy, smoke suppression, thermal degradation behavior, morphology and composition of carbon slag of SiFs with modified MLDHs were tested using the universal tensile testing machine, limiting oxygen index (LOI), UL-94 test, cone calorimeter, thermogravimetry, SEM–EDS and XPS. The results indicated that the modified MLDHs could effectively improve the ductility of SiFs. When the addition of modified MLDHs exceeded 20 mass%, SiFs could be improved to UL-94-V0 rating. The PHRR, THR, and TSP of SiFs with 30 mass% modified MLDHs were 56.04%, 46.86%, and 80.49% lower than that of pure SiFs. Furthermore, the decomposition products of modified MLDHs/SiFs composite such as SiO 2 and zinc magnesium aluminum oxide could improve the char formation significantly. The continuous, complete, and dense structure of carbon slag of modified MLDHs/SiFs could effectively block the exchange of heat and gas on the surface of SiFs and reduce the combustion performance of SiFs.
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Journal of Materials Research and Technology-JMR&T
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2022
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IF 6.267
Zhengwei Guo,Guojian Lin,Lu Li,Peng Cao,Zhentao Yuan,Xiao Wang,Quan Shan,Zulai Li
This study aims to achieve synergistic strength-ductility enhancement of semi-solid squeeze cast 6TiB 2 /Al–17Si–4Cu composites through in-situ particle strengthening and T6 heat treatment. The microstructure and mechanical properties of 6TiB 2 /Al–17Si–4Cu composites with different heat treatments were investigated. TiB 2 particles are semi-coherent with α-Al and primary Si, respectively. The nanoscale precipitate phases were determined by their crystal orientation relationships. The results showed that they are θ and θʹ phases. Meanwhile, the research results pertaining to the mechanical properties imply that the strength and ductility are enhanced by the TiB 2 particles and Al 2 Cu precipitates. The optimum heat treatment process (solution treatment for 9 h at 520 °C and aging for 8 h at 170 °C) of strengthened 6TiB 2 /Al–17Si–4Cu composites is revealed in this study, when the ultimate tensile strength and elongation of the composites are 263.3 MPa and 0.51%, respectively. The mechanisms governing the enhanced strength and ductility of 6TiB 2 /Al–17Si–4Cu composites were discussed.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
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IF 8.025
Songmao Zhang,Yichun Wang,Yawen Li,Long Miao,Keliang Wang
Primary quasi-solid Al-air batteries using hydrogels have attracted increasing research attention owing to their high energy density, good handling, safety and reliability. However, it is still difficult to develop hydrogel electrolytes with high ionic conductivity and water retention owing to limited capacity of single material hydrogels. Herein, we report a hydrogel electrolyte of poly (acrylic acid) (PAA) is modified by κ-carrageenan (KC) for solid-state Al-air batteries. The result suggests that the hydrogels not only exhibit outstanding water retention but also high ionic conductivity, which is attributed to the amorphous phase and hydrophilic group of the KC. Additionally, the lifespan of solid-state Al-air battery is extended at a current density of 5 mA cm −2 owing to adding KC. Further, the lifetime of open Al-air batteries is improved by self-corrosion inhibition of Al anode.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Jingang Wang,Jianbo Zhang,Cheng Xing,Taosheng Jin,Jinpeng Liu,Meiting Ju,Xuejiao Tang
Phosphorus (P) poisoning of NH 3 -SCR catalysts is inevitable in application of NO x abatement of diesel exhaust. The distinct effects on Cu-SSZ-13 of P from different precursors (H 3 PO 4 and (NH 4 ) 2 HPO 4 ) were figured out and the mechanism was further investigated. P-poisoned Cu-SSZ-13 (Si/Al = 6) catalysts were prepared and characterized using N 2 adsorption, X-ray powder diffraction (XRD), scanning electron microscope with energy-dispersive X-ray spectroscopy mapping (SEM-EDX), ammonia temperature-programmed desorption (NH 3 -TPD), X-ray photoelectron spectroscopy (XPS), hydrogen temperature programmed reduction (H 2 -TPR), electron paramagnetic resonance (EPR) and 27 Al solid-state magic angle spinning nuclear magnetic resonance spectroscopies ( 27 Al NMR). Significant enhancement of high-temperature activities (400–600 °C) were observed for the catalysts with P loading of 0.3–0.9 wt%, since the appropriate incorporation enabled to bind P atoms to CuO x in remained framework. However, the high P content of 1.5 wt% resulted in a detrimental effect on framework to induce the accumulation of Cu species. Interestingly, the dominant P from H 3 PO 4 was inclined to directly attack the framework Al leading to more severe dealumination, while the P from (NH 4 ) 2 HPO 4 interacted with Cu 2+ to form copper phosphate with more Cu 2+ migrating to the surface of the catalyst which promoted the NO x conversation at each active site resulting in the low-temperature catalytic activity unchanged. So, control of the P/Cu and form of P is capable of preventing P poisoning and unlocks the potential of Cu-SSZ-13 in exhaust treatment.
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MATERIALS TECHNOLOGY
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2022
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IF 3.297
Haoxin Li,Guangyu Wu,Qi Liu,Jingyi Wang,Siye Xia,Yingcen Xue,Jiangang Han,Chuansong Duanmu,Yongli Zhu
Wastewater contains dye or pharmaceuticals could imply severe environmental impacts due to their toxicity to ecosystems and, consequently, the generation of human health risks. In this work, the orange peel biochar was prepared through pyrolysis, and then Mg/Al-layered double hydroxide (Mg/Al-LDHs) was grown on the surface of the biochar (BC@Mg/Al-LDHs) by hydrothermal method. The material was characterised by SEM, TEM, XRD, XPS and other techniques. The adsorption performance, adsorption isotherms, kinetics and thermodynamics of BC@Mg/Al-LDHs on methylene blue (MB) or tetracycline hydrochloride (TC) were investigated. The results showed that the maximum adsorption capacity of BC@Mg/Al-LDHs for MB and TC were 75.98 and 29.08 mg/g, respectively. The adsorption equilibrium was reached within 30 minutes, and removal percent was 93.99 and 62.06% for MB and TC, respectively. The obtained results investigate that the prepared BC@Mg/Al-LDHs materials for a broad range of applications in dye and pharmaceuticals separation from the water environment.
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Defence Technology
·
2022
·
IF 4.035
Peng Deng,Xue-yong Guo,Hua Fang,Rui Liu,Peng-wan Chen
Combined with the oxidizer anions and fuel cations, molecular perovskite energetic materials show a good potential. In this work, the combustion behavior and mechanism of metal fuel aluminium (Al) with molecular perovskite energetic material (H 2 dabco)[NH 4 (ClO 4 ) 3 ] (DAP-4) as a high-energy oxidant was investigated. The DAP-4 based composites with metal fuel Al were designed and fabricated by the different mass ratios. Results showed that DAP-4 exhibits a good oxygen-supplied capacity for enhancing the combustion performance of Al. The maximum combustion heat of DAP-4/Al-3 at the Al/O mass ratio of 38:62 is up to 10,412 J/g in the inert gas, which is higher than those of other ratios and the mixtures of other energetic materials and Al. The evolution of pressure output, pressurization rate, and flame temperature was monitored for DAP-4/Al with different mass ratios. Composites DAP-4/Al/F were characterized by burning rates. The combustion reaction mechanism of metal fuel Al with DAP-4 as a high-energy oxidant was provided. DAP-4 was ignited firstly and released acid and oxidizing gases, which corroded Al 2 O 3 shells on Al particle surfaces and accelerated the combustion reaction with Al to release a lot of energy. This work offered a new idea that molecular perovskite energetic materials have great potential in the high-energy Al-based solid rocket propellants.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2022
·
IF 6.371
Yang Yu,Xiaoping Cai,Xinyang Jiao,Chengyi Xu,Jinan Niu,Peizhong Feng
Ni-Al-Cr intermetallic compounds are candidate at extreme environment due to their excellent oxidation resistance at high temperature, and the oxidation resistance of Ni-Al-Cr alloy system has been studied extensively. However, the research on oxidation resistance mechanism of porous Ni-Al-Cr intermetallic compounds is still not deep. In our work, porous Ni-Al-Cr intermetallic compounds were synthesized by thermal explosion, and the oxidation resistance of porous Ni-Al-Cr system was mainly investigated. The results indicate that Cr promotes the formation of highly protective continuous Al 2 O 3 layer, increasing the oxidation resistance at 900 °C of porous Ni-Al-Cr. After oxidation at 900 °C for 120 h, the minimum mass gain of Ni-Al-Cr products is only 6.96%.
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COMBUSTION AND FLAME
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2022
·
IF 5.767
Lyu Jie-Yao,Yang Su-Lan,Wu Shixi,Tang Gen,Yang Wenming,Yan Qi-Long
Burning rate modulation is a critical but challenging technology for solid propellants’ design. Great efforts have been made to synthesize and utilize catalysts to modify the pressure exponent ( n ), but poor catalytic efficiency and lower energy level of conventional catalysts limit their further applications. In this research, interfacial control of Al@AP together with precise catalysis of CuO is represented for the purpose of pressure exponent reduction and combustion performance improvement. The core-shell structured Al@AP and Al@AP/CuO composites were prepared and applied into HTPB/Al/AP composite propellants. These prepared propellants have the same formula but different micro-structures of ingredients, leading to varied combustion performance, in terms of the burning rates, combustion wave structures, flame spectra, agglomeration processes of Al particles and condensed combustion products . The investigation results show that by using interfacial control of Al@AP and precise catalysis of CuO, the n of involved propellants over 1–4 MPa can be greatly decreased from 0.42 to 0.21 and the agglomeration of Al could be effectively inhibited. In addition, propellants based on Al@AP and Al@AP/CuO interfacial controls of this research are summarized and compared together with those based on Al@RDX published recently, to present overall characteristics of interfacial control techniques, which could lead to the development of new smart controllable propellants.
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