JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Suwen Li,Gang Wang,Keqiang Zhang,Xueqin Zhang,Lu Zhang,Wenqing Wang,Rujie He
In this paper, Al 2 O 3 functional gradient structures (FGS) were prepared by digital light processing-based 3D printing , and Al 2 O 3 /Al interpenetrated FGS was subsequently obtained by melt infiltrating. The microstructure of Al 2 O 3 FGS and Al 2 O 3 /Al interpenetrated FGS was studied. And the mechanical properties of Al 2 O 3 FGS and Al 2 O 3 /Al interpenetrated FGS under quasi-static compression loading were investigated in detail. Compressive strength , Young’s modulus, and energy absorption of Al 2 O 3 FGS and Al 2 O 3 /Al interpenetrated FGS were experimental tested, compared, and discussed. The failure behavior of Al 2 O 3 FGS and Al 2 O 3 /Al interpenetrated FGS was analyzed by experiments and FEA . This study provides a novel approach for the fabrication of ceramic FGS and ceramic/metal interpenetrated FGS with high mechanical performance.
研究领域:
材料科学
·
工程学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Xiao-Kang Liang,Jia-Wei Mo,Xiao-Gang Jin,Xiao-Hua Ma,Zhen-Liang Xu
Creating a gradient structure in a separation layer is an effective approach for enhancing separation performance of thin film composite membranes . Here we present the preparation of a positively charged nanofiltration membrane with a gradient structure. An inner layer consisting of a loose polyester separation layer with large pores was formed through the interfacial polymerization (IP) reaction between triethanolamine (TEA) and trimesoyl chloride (TMC). And a dense and thin top layer composed of a polyamide separation layer was obtained by secondary interfacial polymerization (SIP) reaction using polyethyleneimine (PEI) along with unreacted TMC and residual acyl chloride groups of IP reaction. The influences of TEA concentration, PEI concentration and SIP time on the physicochemical properties and separation performances of the membrane were systematically analyzed. Our results show that the presence of the gradient structure optimized mass transfer pathways and reduced mass transfer resistance, resulting in significantly improved permeability of 13.0 ± 0.5 L·m −2 ·h −1 ·bar −1 (over 3 times compared with control-PEI), high MgCl 2 rejection of 91.7 ± 0.6 %, and an excellent stability and anti-fouling performance. Our work provides valuable insights and guidance for developing high-performance positively charged NF membrane with gradient structures.
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
Small Science
·
2022
·Vol. 2
·期 7
·2200018
·
IF 0
Yajun Zhang,Long Pan,Peigen Zhang,ZhengMing Sun
High-performance electromagnetic (EM) absorbing materials are in urgent need due to severe EM pollution caused by fast development of communication technology and electronic devices. Gradient structure benefits EM absorbing performance. However, the relevant study is very limited, and the relationship between component layers and overall performance is unclear. Herein, a gradient structure containing impedance matching layer, lossy layer, and reflective layer is built via repeated casting-drying method using Ti 3 C 2 T x MXene and polyvinyl alcohol. With optimized gradient structure, the minimum reflection loss (RL) reaches −74.8 dB with effective absorbing bandwidth (EAB) covering the whole X-band. The good absorbing performance is ascribed to the good impedance matching, which is derived from the stepwisely increased permittivity of each layer. Moreover, it is found that RL reaches the lowest value when lossy layer permittivity is close to the average permittivity of impedance matching layer and reflective layer. In addition, the decrease of lossy layer permittivity causes the decrease of total thickness of the gradient structure. This work demonstrates the effectiveness of gradient structure toward strong and broadband microwave absorption and provides rules for designing proper gradient structures to satisfy different requirements.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Yingying Zhang,Guanglin Fan,Jinqiang Jiang,Zhaotie Liu,Zhongwen Liu,Guo Li
Hydrogel actuators have gained considerable interest and experienced significant advancements in recent years. However, the programming of their actuating behaviors is still challenging. Herein, we report the development and regulation of gradient structures of hydrogels for programmable thermally responsive actuating behaviors. The hydrogel actuators are developed by controlling the photoreduction of Fe3+ ions coordinated with carboxylate groups from the substrates and their limited diffusion into the precursor solutions to act as both initiators and crosslinkers. The developed hydrogels show well-defined external geometries and controllable thicknesses under spatiotemporal control of ultraviolet irradiation. The shapes and the actuation amplitudes of the hydrogel actuators can be independently regulated by controlling the formation and photodissociation of Fe3+–carboxylate coordination in the formed gradient networks. Some interesting applications such as the lifting of an object with a specific shape and directional walking are realized. The proposed method can be extended to other hydrogel actuators with different compositions and stimuli-responsive behaviors.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2025
·
IF 3.3
Qing Zhong,Xiaozhang Song,Jingyi Wang,Wenhui Yu,Ruifen Tian,Yinling Wang
The present study focuses on the electrochemical-mechanical (ECM) coupling effects of a thin-film, solid-state battery with only stiff, ceramic materials, in contrast to prior investigations that focus on individual active material particles or aggregations of particles. We model the impacts of ECM couplings including stress-transport and stress-equilibrium potential on the full-cell performance and potential mechanical failure modes of a thin-film battery conformally deposited in a nanopore scaffold, which is an experimentally achievable device. Model results indicate electrode volume changes due to lithium insertion or removal, along with mechanical boundary conditions, result in stress gradients that alter the lithium-ion flux, reduce lithium concentration gradients, and improve cell rate capability. However, the high stress levels in the cell can also lead to mechanics-related failure such as the separation of cell layers. For the parameter set in this work, stress-transport coupling has a much greater influence on rate capability than stress-potential coupling. Optimization of thin-film batteries to harness the benefits of ECM effects requires leveraging geometric design and material selection. The current work underscores the need for further theoretical and experimental investigation into ECM effects in thin-film batteries to enhance their understanding and design optimization.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
SCRIPTA MATERIALIA
·
2022
·
IF 6.302
Jingkun Xu,Zetan Liu,Jie Zhang,Fei Li,Xiaowei Qin,Shan He,Zhipeng Xie
The effects of various DC electric fields (0–167 V/cm) on liquid-phase hot pressing of Si 3 N 4 ceramics were investigated. The application of a DC field promoted the α→β phase transformation of Si 3 N 4 near the cathode while inhibiting it near the anode. As a result, the Si 3 N 4 ceramics with continuously graded microstructures and mechanical properties were in situ fabricated from a homogeneous raw powder. Although the DC field-driven migration of Mg 2+ and Y 3+ ions was recorded, the graded phase transformation phenomenon was linked to the Peltier effect , which led to additional heating at the cathode and cooling at the anode.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2022
·
IF 5.767
Qianqian He,Jun Wang,Yaofeng Mao,Wei Cao,Jie Chen,Fude Nie
To improve and adjust the combustion and energy output of HMX/Al, graphite fluoride (CF) as oxidizer was introduced in HMX/Al and gradient structured HMX/Al/CF was prepared by additive manufacturing technology . For HMX/Al added with CF, a significantly exothermic peak is observed ranging from 860 to 950 °C due to the reaction of Al and fluorine derived from CF decomposition, and the heat release increases by 106.63% compared to that of HMX/Al. The fourth exothermic heat increases from 161.48 to 955.25 J/g with the increased Al content from 10 to 30 wt%. Moreover, the combustion rate and pressure output of HMX/Al have been improved by introducing CF. For HMX/Al added with CF, the combustion time decreases from 10.3 to 2.5 s, which is dependent on the Al content from 10 to 30 wt%. And the highest peak pressure is 1712.2 kPa when Al content is 20 wt% in HMX/Al/CF composites. Furthermore, gradient structured HMX/Al/CF consisting of three layers with Al content of 10, 20 and 30 wt% was prepared to improve combustion and pressure output. The combustion rate and peak pressure of gradient structured HMX/Al/CF are higher than those of single structured HMX/Al/CF. The highest peak pressure (∼2.24 MPa) is obtained when the Al content of the middle layer and outer layer is 30 wt% and 20 wt% in the gradient structured HMX/Al/CF cylinder, respectively. Finally, the reaction intermediates and combustion reaction products were fully characterized to understand the enhanced effect of CF in HMX/Al. This work provides a promoting way to improve and regulate the combustion reaction performance and pressure output of HMX/Al.
研究领域:
材料科学
·
燃烧学
·
能源材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Meng Ma,Wenting Tao,Xianjun Liao,Si Chen,Yanqin Shi,Huiwen He,Xu Wang
Conductive polymer composites (CPCs) had attracted tremendous attention in the field of electromagnetic interference (EMI) shielding. However, these materials encountered an intrinsic contradiction between high EMI shielding effectiveness (EMI SE) and low electromagnetic waves reflection. Herein, an excellent EMI SE and low electromagnetic waves reflection composite film with a controllable magnetic-conductive dual gradient structure was constructed using cellulose nanofiber (CNF), MXene, and FeCo by layer-by-layer vacuum filtration method. Benefiting from the synergy of the transition layers and reflection layer with gradient structure, the composite film exhibited favorable impedance matching, abundant loss mechanism, and efficient EMI shielding ability, resulting in absorption dominated shielding characteristic. In addition, the gradient structure facilitated the “absorb-reflect-reabsorb” process when electromagnetic waves were transmitted into the composite film. The obtained CNF/MXene/FeCo-G composite film possessed a remarkable EMI SE of 58.0 dB and the reflection coefficient (R) as low as 0.61. It was proven that the electromagnetic waves absorbing ability can be enhanced by thickening the transition layers, and the EMI SE was improved with the thickening of the reflection layer. Therefore, this work provided a facile strategy to prepare high EMI SE materials with low reflection, which had a good application prospect as the new-generated smart electronic devices.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Jing Huang,Jiawei Dai,Jiannan Zhu,Rong Chen,Xiaoqi Fu,Hongfang Liu,Guangfang Li
Electrocatalytic reduction of CO 2 (CO 2 RR) represents a promising approach to reduce CO 2 emission and generate value-added chemicals. Herein, we developed bimetallic Au-Cu gradient alloy nanostructures (AuCu-g) comprising of ultrathin Cu-rich alloy surface and Au-rich alloy core as electrocatalyst via a facial solvothermal method. Impressively, the AuCu-g can stably generate a considerable amount of C 2 H 4 with faradaic efficiency (FE) ∼20 % at a low limiting potential of −0.4 V versus reversible hydrogen electrode (RHE) due to its unique gradient structure and multi-component tandem effect. The potential-dependent in situ Raman spectrum indicated an enhanced *CO adsorption strength and a remarkable CO intermediate generation over Au-Cu gradient alloy at low overpotentials during CO 2 reduction process. This work shines a light for developing mutilmetallics toward efficient CO 2 RR.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES COMMUNICATIONS
·
2025
·
IF 7.7
Liqiang Shang,Hao Zheng,Jiali Chen,Yiming Ren,Wenge Zheng,Bin Shen
Construction of conductive polymer composites (CPCs) for green electromagnetic interference (EMI) shielding with efficient shielding effectiveness (SE) but low EM reflection is urgently needed. Though the introduction of cellular or gradient structures can effectively reduce EM reflection, most current methods for preparing gradient CPC foams are relatively complex and lack sufficient applicability for large-scale production. Herein, we demonstrate the convenient fabrication of gradient-structured EVA/carbon nanostructure (CNS) foams through chemical foaming of thermally molded EVA/CNS composites with gradient CNS construction. Compared to uniform EVA/CNS foams, lower R coefficient with an effective EMI SE of >20 dB was obtained for gradient EVA/CNS foams with 3 phr CNS, accompanied by an average green shielding index (g s ) of ∼2.8. This study provides a more feasible two-step process of thermal press molding and chemical foaming for mass manufacturing of gradient CPC foams with effective green EMI shielding characteristics.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2024
·
IF 10.5
Guangda Guo,Fang Ye,Laifei Cheng,Yucong Wei,Xu Chen
C f /SiC-ZrC renowned for its outstanding performance as a thermal protectant, has gaining widespread recognition. Recent research on this system has emphasized the development of a cost-effective and reusable version with increased thickness for extended use in thick-walled thermal structural components. Ablation resistance, high strength retention, and high thermal conductivity are crucial for successful aircraft reentry. In this study, a low-cost reactive melt infiltration (RMI) method is developed for preparing dense and high-performance large-thickness C f /SiC-ZrC (L-C f /SiC-ZrC) with a gradient-structured matrix. The use of a fine weave-pierced fabric preform structure enhances both the structural integrity and thermal conductivity of C f /SiC-ZrC in the thickness direction. Simultaneously, the gradient-structured matrix, with appropriate contents of surficial ZrC and SiC exhibits erosion resistance, where the internal core with a high SiC content ensures remarkable strength retention. This unique matrix-structure design is achieved by integrating porous C with a single-stage pore structure and a high degree of graphitization degree, and a Si-Zr alloy with a unique composition. The 20mm thick C f /SiC-ZrC obtained via RMI has a density of 2.79 g/cm 3 with an open porosity of 5.65% and flexural strength of 224.3±5.4 MPa. Under a heat flux of 4.186 MW/m 2 , C f /SiC-ZrC exhibits an ablation rate of −0.004 mm/s after 60 s, demonstrating its resilience against ablation damage. Moreover, the post-ablation strength (166.0±4.4 MPa) exceeds that of reported C f /SiC-ZrC congeners, highlighting the robust load-bearing capability.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Zhenming Chu,Weicheng Jiao,Jun Li,Hongyuan Guo,Yongting Zheng,Rongguo Wang,Xiaodong He
The application of strain sensors in extreme environments (such as moisture or rain droplets) is limited by the influence of water molecules on their sensing performance. Endowing strain sensors with superhydrophobicity is a promising strategy to solve this problem. However, it remains a challenge for superhydrophobic strain sensors to completely avoid the effects of water droplets. Herein, we developed a superhydrophobic strain sensor with gradient structure for the first time by a simple one-step pre-stretching method. The strain sensor exhibits high sensitivity (maximum gauge factor of 1199.10), a broad strain range (up to 400%), robust stability (3000 cycles), a low detection limit (0.1% strain), and fast response (88 ms), which can be used to monitor full-range human body motions. Furthermore, the gradient wrinkle structure with low surface energy makes the strain sensor have gradient superhydrophobic performance, so that the impacting water droplets can automatically deviate and bounce off the surface by the Young's force, avoiding the interference of water droplets on the sensor's electrical signal. Even when the strain is up to 400%, the impacting droplet can still offset and rebound, which makes the superhydrophobic strain sensor have stable sensing performance in extreme environments.
研究领域:
材料科学
·
生物医学工程
✓ 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）