Polymers
·
2022
·Vol. 14
·期 18
·3912
·
IF 4.967
Juan Yi,Yiheng Song,Shixian Zhang,Zhilong Cao,Chenjian Li,Chuanxi Xiong
For digging out eco−friendly and well−performed energy harvesters, piezoelectric nanogenerators are preferred owing to their effortless assembly. Corona−poling promotes output performance of either aligned or porous PVDF electrospun films and higher piezoelectric output was achieved by corona−poled porous PVDF electrospun films due to more poled electret dipoles in pores. Increasing the duration of electrospinning rendered more electret dipoles in PVDF porous electrospun films, resulting in higher piezoelectric output. Moreover, corona−poled PVDF/Y−ZnO porous electrospun films performed better than corona−poled PVDF/ZnO porous electrospun films because of the larger polar crystal face of Y−ZnO. Flexible piezoelectric polymer PVDF and high−piezoelectric Y−ZnO complement each other in electrospun films. With 15 wt% of Y−ZnO, corona−poled PVDF/Y−ZnO porous electrospun films generated maximum power density of 3.6 μW/cm2, which is 18 times that of PVDF/BiCl3electrospun films.Keywords:poly(vinylidene fluoride);Y−ZnO;electrospining;corona poling;wearable device
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 59
·88866-88881
·
IF 5.19
Xia Xuewen,Li Junqi,Chen Chaoyi,Lan Yuan-Pei,Mao Xisong,Chu Zhiyao,Ning Deyang,Zhang Junshan,Liu Fengyuan
Tuning morphology and doping additional rare earth (RE) cations are potential techniques to promote the photocatalytic performance of ceria (CeO 2 ), evaluating the collaborative effects of morphology and RE dopants is significant for producing high active ceria-based catalysts. So in this work, cubic, polyhedral and rod-like nanoceria doped with 10 mol % La (lanthanum), Y (yttrium), or Sm (samarium) were synthesized by a facile template-free hydrothermal method. Phases, morphologies, oxygen vacancies (OVs) concentration, energy band structure, photo-carriers separation/recombination, and photodegradation ratio toward methylene blue (MB) dye of as prepared ceria were studied. Results show that doped CeO 2 maintains a similar morphology structure with un-doped sample and the band gap narrows slightly. Y-doped nanoceria, with an improved separation and a reduced recombination of photo-excited electrons ( e − ) and holes ( h + ), owns a higher MB photodegradation ratio than that of samples doping with La or Sm, which is measured as 79.04, 84.43, and 85.59% for Y-doped cubic, polyhedral, and rod-like CeO 2 . The collaborative influence of morphology tuning and RE (La, Y, and Sm) doping on photocatalytic performance of nanoceria includes the effects of doped elements and the formation of OVs. The elevation of OVs concentration as well as the separation efficiency of photo-generated e − / h + are suggested to further enhance the photocatalytic performance of ceria.
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MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
Yuanming Gao,Yu Bai,Peng Zhang,Li Sun,Caiwen Liu,Hongying Dong,Qing Geng,Wei Wang,Wen Ma
In this study, the Yb–Y co-doped SrZrO 3 (SZ) coatings [SZYY-1 (Sr 1.0 (Zr 0.9 Yb 0.05 Y 0.05 )O 2.95 ), SZYY-2 (Sr 0.9 (Zr 0.9 Yb 0.05 Y 0.05 )O 2.85 ), and SZYY-3 (Sr 0.8 (Zr 0.9 Yb 0.05 Y 0.05 )O 2.75 )] were deposited by SPS (Suspension plasma spray) using the corresponding co-precipitation prepared precursors suspension. In the three as-sprayed SZYY coatings, there were some typical suspension plasma-sprayed coating structures, such as columnar crystals, vertical cracks, and micro/nanopores. The TCs (Thermal conductivities) of the three as-sprayed SZYY coatings were 1.23–1.88, 0.80–1.41, and 0.88–1.43 W/(m · K) at 100–1400 °C, respectively, which were at least 19% lower than that of the SZ coating (1.25 W/(m · K), 1000 °C). The TECs (Thermal expansion coefficients) of the three as-sprayed SZYY coatings were (7.8–8.7) × 10 −6 , (8.0–9.8) × 10 −6 , and (8.1–9.8) × 10 −6 /K, respectively (200–1360 °C). The sintering coefficients of the three as-sprayed SZYY coatings were 5.69 × 10 −6 , 4.29 × 10 −6 , and 3.84 × 10 −6 /s, respectively. The SZYY-3 coating showed the best SR (Sintering resistance), followed by the SZYY-2 coating and SZYY-1 coating. The SPS SZYY-2 coating with good phase stability, low TC (Thermal conductivity) and good SR is a promising new TBCs (Thermal barrier coatings) material. It is expected to be an alternative TBCs material for the next generation of high performance gas turbines .
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COMPOSITES PART B-ENGINEERING
·
2022
·
IF 11.322
Zizhang Zhan,Wei Sun,Shuaishuai Zhang,Qingbo Wen,Hongbo Zhang,Xiang Xiong
A (AlCrMg) x (PO 4 ) y /MgO composite(APMC) was prepared based on the acid–base reaction between MgO and chromium aluminum phosphate solution for thermal protection and insulation applications at ultrahigh-temperatures up to 2400 °C. The compositions, formation mechanisms, microstructure, mechanical properties , thermal conductivity and ablation resistance of the composite were systematically investigated. The results show that the (AlCrMg) x (PO 4 ) y /MgO composite can be consolidated in different shapes at room temperature. The compressive strength of the as-prepared porous composites is higher than 20 MPa due to the macromolecular network structure, and it can be further improved to 42 MPa via thermal treatment. After ablation by an oxyacetylene flame at 2400 ± 70 °C for 60 s, the mass and line ablation rates of the composite were 0.0195 g/s and 0.43 × 10 −3 mm/s, respectively, which are comparable to those of ultrahigh-temperature ceramics. The excellent ablation resistance can be attributed to the in situ formation of a dense protective layer composed of spinel MgCr 2 O 4 and MgO phases. Interestingly, during ablation at 2400 °C the back-side temperature of the 15 mm-thick sample was lower than 130 °C, suggesting outstanding thermal insulation performance. The temperature gradient leads to the formation of a gradated porous structure which reduces the overall thermal conductivity of the composite.
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MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2019
·Vol. 221
·期 3
·1900421
·
IF 2.622
Xiongliang He,Xiaodan Wang,Rongtao Zhou,Hua Lu,Shifang Luan,Haoyu Tang
Biocompatible and biodegradable thermoresponsive polymers are of great interest in “smart” biomedical applications. Herein, triblock copolymers (6a and 6b) comprised of hydrophobic poly(propylene glycol) (PPG) and OEGylated polypeptides bearing Y-shaped or linear pendants are prepared by ring-opening polymerization of reactive N -carboxyanhydride monomers and subsequent side chain modification of polypeptides. OEGylated triblock copolymer bearing Y-shaped (6a) or linear pendants (6b) with similar main chain length and the same amount of oligo(ethylene glycol) (OEG) units are successfully prepared as verified by 1 H NMR, FTIR, and GPC. CD analysis reveals that 6a with Y-shaped OEG pendants shows thermal- or salt-induced destabilization of α-helical conformation in water. Both 6a and 6b show reversible lower critical solution temperature (LCST)-type phase transitions in DI H 2 O or PBS. Incorporation of a PPG segment leads to a significant decrease of the LCST-type cloud point temperature ( T cp ). Consequently, 6a and 6b show T cp to human body temperature at low polymer concentrations (≤0.5 mg mL −1 in PBS). Moreover, 6a and 6b show low in vitro cytotoxicity and biodegradability in the presence of proteinase K. The results indicate that the thermoresponsive properties of LCST-type polymers can be readily tuned by constructing Y-shaped pendants as well as incorporation of hydrophobic polymer building blocks.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Jia Liu,Hong Yang,Zhaoyang Song,Jing Sun,Xinwen Guo
In this study, Pt/ZSM-22, Pt/Y, Pt/ZSM-22 + Y (the support is a mechanically blended mixture of ZSM-22 and Y at 1:1 weight ratio), and Pt/ZSM-22 – Y (the support is NaOH + CTAB-treated ZSM-22 + Y) with 0.5 wt % of Pt loading were synthesized and applied as catalysts in the hydroisomerization of n-dodecane. The microstructures and acidic properties of these catalysts were characterized by XRD, TEM, BET, N2 adsorption–desorption isotherms, NH3-TPD, Py-IR, and 27Al-NMR. This study revealed significantly different acidic properties and catalytic performances between the mechanically mixed Pt/ZSM-22 + Y and post-treated Pt/ZSM-22 – Y. In particular, Pt/ZSM-22 – Y not only delivers a high n-dodecane conversion but also significantly enhances the yield and selectivity of multibranched iso-dodecane. This enhanced selectivity of multibranched iso-dodecane may be attributed to the high number of medium-strong acid sites and increased mesopores generated by the post-treatment process.
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Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 46
·16143-16151
·
IF 6.4
Yixiao Han,Leipeng Li,Chongyang Cai,Pei Li,Tao Li,Xiumei Han,Dengfeng Peng,Yanmin Yang
Mechanoluminescent materials have gained considerable attention over the past few years due to their unique characteristic of converting some useless mechanical actions in our daily life like compression and friction into usable light sources. However, the application scenarios of mechanoluminescent materials are still quite limited, mainly to stress sensors and visualization of pressure. Our work aims to solve this problem. Here, we demonstrate that Y2O2S:Er3+ with excellent mechanoluminescence (ML) could be used for energy-saving temperature sensing. Upon stimulation of external force, Y2O2S:Er3+ emits bright green ML that is attributed to the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of Er3+. These transitions are confirmed to conform with the Boltzmann distribution during a dynamic temperature-changing test. In addition, we confirm the feasibility of the ML thermometry framework in Er3+-doped Gd2O2S and Lu2O2S. Our work provides a new perspective for broadening the application scenarios of mechanoluminescent materials.
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RENEWABLE ENERGY
·
2020
·
IF 6.274
Hui Yong,Xin Wei,Jifan Hu,Zeming Yuan,Ming Wu,Dongliang Zhao,Yanghuan Zhang
A composite catalyst Fe@C was successfully prepared by chemical blowing and carbonization method, at the same time its defect level, pore distribution and specific surface area were investigated. In addition, the Mg–Ce–Y + x wt.% Fe@C ( x = 1, 3, 6, 10) composites also were synthesized by mechanical ball-milling. The effect of the Fe@C content on hydrogen absorption and desorption property of the Mg–Ce–Y alloy was characterized by XRD, SEM , TEM, PCI , and DSC method. The activated composites exhibit an excellent absorption and desorption kinetic performance, which attributeed to the efficient catalysis of Fe@C composite catalyst. The Mg–Ce–Y + 6 wt % Fe@C composite exhibits the fastest hydrogen absorption/desorption kinetics and relatively lower decomposition temperature and it can absorb 90% of the maximum hydrogen capacity within 2 min and only takes 12 min to release the same amount of hydrogen under 300 °C. Besides, the dehydrogenation activation energy is reduced to 84.9 kJ/mol and the initial hydrogen release temperature is less than 250 °C, which is owing to the outstanding synergistic catalyst effect of Fe@C on Mg-based hydrogen storage alloy . However, the thermodynamic properties of the composites have not been improved, of which the enthalpy change is 80.6 kJ/mol.
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CHEMISTRY-A EUROPEAN JOURNAL
·
2020
·Vol. 26
·期 64
·14654-14664
·
IF 4.857
Yi Cao,Peiyuan Tang,Yue Han,Wenfeng Qiu
Graphical Flexible film : Flexible thin films of La 2 Y x Zr 2− x O 3 (LNF- x ) ( x= 0, 0.1, 0.3, 0.5) nanofibers are synthesized and characterized. The LNF-0.1//LNF-0.1 flexible device shows good electrochemical performance and is of great significance in the field of next-generation flexible energy-storage devices and applications in portable and wearable electronics. With the rapid development of wearable electronics devices, there is increasing demand for the development of new flexible energy storage devices with high security, and this has become a hot research topic. Although flexible supercapacitors are considered to be high-performance energy-storage equipment because of their fast charging/discharging ability, long cycle life, good reliability, wide operating temperature range, and so on, there are still many drawbacks that need to be overcome. Herein, the La 2 Zr 2 O 7 (LZO) thin film is synthesized as a new energy-storage material by using a facile electrospinning method and calcination at low temperature. In addition, the mechanism of producing the flexibility of this film is determined by TG, IR, and XRD analyses. As previous studies have suggested that the charge storage of the LZO film can be attributed to the mechanism of oxygen intercalation, the Y element is doped into the LZO film to increase the concentration of oxygen vacancies. The changes in structural and electrochemical properties of La 2 Y x Zr 2− x O 3 (0≤ x ≤0.5) nanofibers (LNF- x ) with increasing Y content are studied carefully to obtain the best doping sample. The LNF-0.1 sample shows the highest areal capacitance of 605.3 mF cm −2 at 2 mA cm −2 , so a symmetrical flexible device is fabricated with LNF-0.1 electrodes. This device has a high energy density (76.7 μW h cm −2 at 2 mW cm −2 ), good cycling stability, and excellent mechanical flexibility. This study thus provides a new research trend for portable and wearable electronics.
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EUROPEAN JOURNAL OF PHARMACOLOGY
·
2021
·
IF 4.432
Yao Hua,Limei Zhou,Weidong Yang,Wenji An,Xiaolin Kou,Jian Ren,Hailang Su,Rong Chen,Zhengping Zhang,Jianjun Zou,Zhihong Zhao
Intracerebral hemorrhage (ICH) is a devastating disease, and there is currently no specific pharmacological treatment that can improve clinical outcomes. Y-2 sublingual tablets, each containing 30 mg edaravone and 6 mg (+) - borneol , is undergoing a phase III clinical trial for treatment of ischemic stroke in China. The purpose of the present study is to investigate the efficacy and potential mechanism of Y-2 in a rat model of collagenase IV injection induced ICH. Sublingual administration of Y-2 at the dose of 1, 3 and 6 mg/kg improved ICH-induced sensorimotor dysfunction, alleviated cell death and histopathological change, restored the hippocampal long-term potentiation (LTP), reduced brain edema and maintained blood-brain barrier (BBB) integrality in ICH rats. Further study demonstrated that Y-2 could reduce inflammatory response and oxidative stress by decreasing the levels of myeloperoxidase (MPO), ionized calcium-binding adaptor protein-1 (Iba-1), inflammatory cytokines and oxidative products, inhibit transcription factor nuclear factor-κB (NF-κB) activation, cyclooxygenase-2 (COX-2) and matrix metallopeptidase 9 (MMP-9) expression in brain tissue around in the core regions of hematoma . Importantly, the protective efficacy of Y-2 from ICH-induced injury was superior to edaravone. In conclusion, Y-2 sublingual tablets might be a promising therapeutic agent for the treatment of ICH.
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高影响因子
FUEL
·
2019
·
IF 5.128
Ze Zhang,Jun Cheng,Yi Qiu,Xi Zhang,Junhu Zhou,Kefa Cen
To clarify the conversion mechanism of methyl palmitate (C16:0) to produce jet biofuel over Ni/desilicated meso-Y zeolite catalyst, quantum chemistry calculation and verification experiments were conducted to evaluate three proposed competitive reaction pathways, in which hydrodecarboxylation pathway was more feasible than hydrogenolysis and decarboxylation pathways. It was found that overall enthalpy change to produce pentadecane (−130.2 kJ/mol) in hydrodecarboxylation pathway was lower than that to produce palmitic acid (−90.1 kJ/mol) in hydrogenolysis pathway and that to produce hexadecane (−68.6 kJ/mol) in decarboxylation pathway. The experimental results of hydrodeoxygenation and hydrocracking conversion of methyl palmitate into jet biofuel were consistent with quantum chemistry calculation, when conventional Y zeolite was modified into hierarchical mesoporous Y zeolite catalyst by desilication with NaOH and then loading Ni nanoparticles. The jet biofuel product selectivity reached a peak (64.8%) with reasonable composition distributions, when Ni/meso-Y zeolite was desilicated with 0.4 M NaOH to promote BET surface area (554.9 m 2 /g) and specific pore volume (0.340 cm 3 /g) with 2–10 nm mesopores. The relative content of pentadecane in liquid products was always higher than those of palmitic acid and hexadecane over Ni/meso-Y zeolite catalysts desilicated with various concentrations of NaOH. The main compositions of gas phase by-products in hydrodeoxygenation and hydrocracking conversion were CH 4 with selectivity up to 25.2% and CO 2 with selectivity of ∼10%, which agreed well with quantum chemistry calculation results.
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Journal of Physical Chemistry C
·
2018
·
IF 4.484
Zhiqiang Xie,Congbiao Chen,Bo Hou,Dekui Sun,Heqin Guo,Jungang Wang,Debao Li,Litao Jia
The nature of high-silica H–Y acid sites in dimethoxymethane carbonylation is investigated by NH3 poisoning with a combination of reaction results, diffuse reflection infrared Fourier transform spectra, and NH3 temperature-programmed desorption. After NH3 poisoning of H–Y, ammonia desorption of zeolites NH4–Y was conducted at different temperatures to obtain catalysts HNH4–Y that gradually exposed different acid sites. The zeolites thus produced catalyzed dimethoxymethane carbonylation with a linear dependence of the conversion on the ammonia desorption temperature before the plateau stage. It was observed that strong Brønsted acids in zeolite Y catalyzed the reaction more selectively toward the main product methyl methoxyacetate, and weak Brønsted acids catalyzed the reaction more selectively toward the byproduct methyl formate. Furthermore, the turnover frequency of Brønsted acids varied significantly among the Brønsted acids and decreased with acid strength. This finding suggested that only 10.1–18.3% of the total Al in zeolite Y with Si/Al ratios of 15, 30, and 40 contributed to the total framework Brønsted acids.
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危险品化学品经营许可证（带存储）