MATERIALS & DESIGN
·
2022
·
IF 9.417
Jia Yang,Wanqi Zhao,Panpan Lin,Qiuguang Zhang,Xinfei Zhang,Weihang Liu,Tiesong Lin,He Peng,Yanli Zhuang
We designed a composite filler beginning with becoming light elements to be the main diffusing elements and (ii) controlling the diffusion of the light elements. It was achieved by establishing chemical potential and supercooling gradients and shortening the diffusion distance. As a result, a transient liquid phase bonding (TLP) composite joint with hedgehog-like reinforcements and a ductile matrix was obtained. The room-temperature (RT) shear strength of the joint produced at 460 °C for 30 min was up to 84 MPa, and it had a strength of 30 MPa at 600 °C. The hedgehog-like” reinforcements with finer or longer whiskers can provide a better load transfer effect. The progressive phase formation around NiTi was induced by the large supercooled liquid, wherein either the fastest-solidified region or the deepest-supercooled liquid served as a barrier for metallic atoms. Consequently, the lower supercooling and higher Si chemical potential in the farther region enable Si to directionally diffused towards the NiTi. This study offered a novel filler feasible for most ceramic/metal systems with the goals of low-temperature joining and high-temperature using and controllable product distribution; and this idea can be extended to develop other systems.
研究领域:
材料科学
·
焊接工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 3
·2037-2048
·
IF 2.993
Wang Kelai,Liang Zheng,Li Jingling,Xu Xueqing,Cheng Xiaoling,Jin Hu,Xu Dehua,Xu Gang
Photoluminescent CuIn(Se x S 1 − x ) 2 (CISeS) nanocrystals (NCs) have been synthesized utilizing copper iodide (CuI) and indium acetate (In(Ac) 3 ) as metal cation precursors, Se powder and n -dodecanethiol (DDT) as selenide and sulfur source, combined with oleylamine and n -dodecanethiol as coordinate ligands at a moderate reaction temperature of 200 °C. The obtained CISeS NCs consisted of a gradient composition that the content of selenide increased from the nuclei to the surface. With the growth of NCs, they exhibited a tunable photoluminescent emission ranging from 722 to 830 nm which was size- and composition-dependent. The photoluminescent quantum yield of the NCs could be further enhanced from 1.2 to 40.7% after ZnS coating due to the formation of ZnCuIn(Se x S 1 − x ) 2 /ZnS (ZnCISeS/ZnS) core–shell structures with the alloyed core. The photoluminescence emission mechanisms of CISeS NCs indicated that the gradient composition structure of CISeS led to a gradient energy level of its conduction band (CB)/valence band (VB), resulting in the charge transfer from the nuclei to the surface through the quantized CB/VB. This transfer process has quenched fluorescence emission arising from the quantized CB/VB and defect states located in the nuclei, such as irradiation relaxation between quantized CB and \( V_{\text{Cu}}^{ \prime } \) . This mechanism could illuminate why the indium-rich CISeS NCs did not exhibit better photoluminescence properties.
研究领域:
材料化学
·
纳米科学
·
半导体光学
·
光电子学
·
胶体化学
·
能源材料
✓ 已验证
DOI
高影响因子
PHYSICS OF FLUIDS
·
2024
·Vol. 36
·期 6
·
IF 4.1
Li Gu-Yuan,Yu Jia-Jia,Duan Cheng-Cheng,Sun Shouli,Wu Chun-Mei,Li You-Rong
In this work, efficient microfluidic flow rate tuning based on the asymmetric flow of nematic liquid crystal 5CB under a horizontal temperature gradient is studied. Rectangular microchannels with the width of 100 μ m are fabricated through soft lithography and treated with homeotropic surface anchoring conditions. Polarized optical microscopy is applied to explore the unique optical anisotropic characteristics of the nematic liquid crystal. The asymmetric velocity profiles in the microchannel are obtained by particle tracking velocimetry. The effects of temperature, flow rate, and aspect ratio on the velocity profile and split ratio of the asymmetric flow are quantitatively studied for the first time, while the mechanism of the flow asymmetry of the nematic liquid crystal is discussed. The results show that the asymmetric flow of the nematic liquid crystal occurs after the horizontal temperature gradient is applied, with the velocity in the heated region markedly higher than its counterpart. The split ratio of the asymmetric flow increases with the increase in the temperature gradient and the decrease in the flow rate. The aspect ratio influences the asymmetric flow through approaches of average velocity and surface anchoring strength, while the former is more distinct. The impacts of temperature gradient, flow rate, and aspect ratio on the flow asymmetry of nematic liquid crystals are caused by the coupling between physical properties, velocity field, and director field. Microchannels based on the asymmetric flow characteristics of nematic liquid crystals can act as a novel kind of temperature-controlled microvalve to achieve efficient microfluidic flow tuning.
研究领域:
物理学
·
微流控技术
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Materiomics
·
2024
·
IF 8.4
Jie Peng,Jie Jiang,Shuoguo Yuan,Pengfei Hou,Jinbin Wang
Ferroelectric materials are ideal for self-powered sensors in Internet of Things (IoT) and high-precision detection systems due to their excellent polarization properties. Compatibility with miniaturization, high-density systems, and complementary metal oxide semiconductor (CMOS) processes is crucial for their widespread adoption. HfO 2 -based ferroelectric films show potential in self-powered pyroelectric sensors as their thinness enables effective temperature and light detection. However, the disordered ferroelectric domain distribution limits their pyroelectric performance and hampers the development of highly integrated self-powered pyroelectric devices. This report investigates the temperature and light detection capabilities of Ce-doped HfO 2 ferroelectric films, which exhibit as-grown spontaneous polarization in the downward direction, making them a promising option for self-powered pyroelectric sensors. The findings provide robust evidence that the introduction of a temperature gradient significantly enhances pyroelectricity. In addition, their applications in the detection of hot/cold wind and breathing have been proved. Notably, the 30 nm thick Ce-doped HfO 2 ferroelectric film has a high pyroelectric coefficient of about 894.7 μC·m −2 ·K −1 and enables high-precision detection of changes in temperature of 0.1 K. This study highlights the potential application of HfO 2 -based ferroelectric films in self-powered sensors with temperature and light detection capabilities, making them a promising candidate for future IoT-based systems and high-precision detection systems.
研究领域:
材料科学
·
传感器技术
·
物联网
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yicheng Li,Mengqi Du,Li Yang,Yunjia Bao,Yewei Xu,Qiang Yin,Yang Lan,Guanjun Chang
Biomimetic actuators have seemingly infinite potential for use in previously unexplored areas. However, large stresses and a rapid water response are difficult to realize in soft actuators, owing to which their practical applicability is currently limited. In this paper, a new method for designing and fabricating humidity-responsive sturdy hard actuator. By combining a rigid matrix and hydrophilic water domains consisting of dynamic interlocking cation-π blocks, high-performance polymer actuator was synthesized that swell rapidly in response to a water gradient in their environment, resulting in unprecedentedly large stresses. More critically, the strong interlocking cation-π blocks reform and the intermolecular distance is reduced when the water is removed, allowing the deformed actuator to revert its original shape. The proposed design principle can potentially be extended to produce different types of sturdy actuators with rapid water responsiveness.
研究领域:
材料科学
·
仿生学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Feiran Li,Shuai Wang,Xuezeng Zhao,Lu Shao,Yunlu Pan
Porous materials with opposing superwettability toward oil and water have aroused widespread interest for their selective-wetting advantage in oil–water separation. The separation process, however, requires constant energy input to maintain the driving force. Further reducing the external energy consumption or accelerating the liquid transport during separation is still a challenge. The Janus membrane is an emerging porous material with opposing wettability toward a specific liquid on each side. The asymmetric wettability distribution leads to a surface energy gradient-driven liquid-transport behavior through the thickness, which significantly facilitates liquid transportation. It is conceived that porous materials possessing both Janus features and selective superwettability would reduce energy consumption and strengthen the efficiency in oil–water separation. Herein, a novel durable superoleophobic (SOHB) Janus fabric which possesses oil-repellent and surface energy gradient-driven water-transport properties was developed through one-side superoleophobic/superhydrophilic modification of the superamphiphobic fabric. The SOHB Janus fabric exhibits high mechanical durability and significant superior capacity than the homogeneous superoleophobic/superhydrophilic fabric in separating various oil–water mixtures. Moreover, the SOHB Janus fabric repels oil contaminants and pumps perspiration from the human skin, exhibiting prospects in physical moisture regulation and comfort improvement. Our novel Janus fabric, along with the fabrication principle, provides a feasible solution for energetic-efficient oil–water remediations and would have implications for the fabrication of advanced separation membranes and intelligent functional clothing.
研究领域:
材料科学
·
环境科学
·
纺织工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Shouze Li,Zhou Li,Dongyan Xu,Run Hu
Emerging thermocells exhibit a significant potential in low-grade heat harvesting owe to their high mV-scale thermopower, low cost, and high robustness. Fundamentally, three effects contribute to the thermopower enhancement of liquid thermocells, i.e. original concentration effect, solvation effect, and normalized concentration gradient effect. Yet, the contribution of the solvation effects and the normalized concentration gradient in organic solvents remains a subject of debate. In this paper, we integrate experiments, spectral analysis, and electrochemical theory to demonstrate that the normalized concentration gradient dominates the enhancement of thermopower in the investigated organic solvents, whereas the solvation effect is weak. Further, the introduction of ethanol results in a thermosensitive solubility of K 4 Fe(CN) 6 and a minimal concentration at the cold end, which establishes a huge substantial normalized Fe(CN) 6 4- concentration gradient and increases the Seebeck coefficient to 3.4 mV/K. Simultaneously, the precipitation resulting from the introduction of an organic solvent notably diminishes the heat convection within the system. As a result, the optimized TC-35EtOH system yields a ZT value (0.094) and Carnot-relative efficiency (2.52 %) that are 7 times greater than those of its initial counterpart. Additionally, the system’s high power density of 3.64 W/m 2 suggests its potential for harnessing low-grade heat waste energy.
研究领域:
物理化学
·
能源材料科学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2021
·Vol. 12
·期 1
·1-6
·
IF 14.919
Li Jidong,Long Yuyang,Hu Zhili,Niu Jiyuan,Xu Tiezhu,Yu Maolin,Li Baowen,Li Xuemei,Zhou Jianxin,Liu Yanpeng,Wang Cheng,Shen Laifa,Guo Wanlin,Yin Jun
External photo-stimuli on heterojunctions commonly induce an electric potential gradient across the interface therein, such as photovoltaic effect, giving rise to various present-day technical devices. In contrast, in-plane potential gradient along the interface has been rarely observed. Here we show that scanning a light beam can induce a persistent in-plane photoelectric voltage along, instead of across, silicon-water interfaces. It is attributed to the following movement of a charge packet in the vicinity of the silicon surface, whose formation is driven by the light-induced potential change across the capacitive interface and a high permittivity of water with large polarity. Other polar liquids and hydrogel on silicon also allow the generation of the in-plane photovoltage, which is, however, negligible for nonpolar liquids. Based on the finding, a portable silicon-hydrogel array has been constructed for detecting the shadow path of a moving Cubaris. Our study opens a window for silicon-based photoelectronics through introducing semiconductor-water interfaces.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Zhe Hong,Lihua Deng,Fanglin Wang,Fangyu Zhu,Yingsen Fang,Li Song,Lei Li,Zhirong Zhu
ZSM-5 zeolites with accessible micropore architecture and tunable acid–base sites are important shape-selective catalysts. However, the presence of exposed straight channels and the external acid–base sites of conventional ZSM-5 has a negative impact on shape selectivity. Herein, we report on the direct synthesis of an intergrowth ZSM-5 zeolite mimicking the mortise–tenon joints. It can be revealed by various methods that the mortise–tenon ZSM-5 shows an inverse Al gradient from the surface to the core of the zeolite. More importantly, the sinusoidal channels predominantly opened to their external surfaces are constructed. The shape-selective capability of the ZSM-5 zeolite has been fully exploited due to the intrinsic inert external surface and unique sinusoidal channel features, thereby resulting in high styrene selectivity (>90%) and good catalytic stability (>100 h) in the toluene side-chain alkylation reaction. In addition, in situ DRIFTS confirms that this intergrowth ZSM-5 contributes to the formation of more active intermediates of HCOO* and H3CO*, which is another reason responsible for the superior performance.
研究领域:
材料科学
·
催化化学
·
无机合成
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Fei Chen,Mingyong Jia,Yulong She,Yueqi Wu,Qiang Shen,Lianmeng Zhang
In this paper, aluminum nitride (AlN) and molybdenum (Mo) were used for fabrication of AlN/Mo functionally graded materials by spark plasma sintering (SPS). In order to study the influence of microstructure on mechanical properties in AlN/Mo FGMs, the FGMs with different composition exponent p value were analyzed by indentation and bending test . The results showed that the specimens with p < 1 exhibited a metal-rich graded structure comparing to specimens with p ≥ 1. The radial bending and shear strength of AlN/Mo FGMs reached maximum when p < 1, which are 369.78 MPa and 48.01 MPa respectively. Moreover, comparing with the porosity and the ceramic/metal interface, the distribution of the two components is the most important factor for improvement of bending and shear strength. The more the hard metal network content in the graded layer, the higher the bending and shear strength of AlN/Mo FGMs.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
Advanced Membranes
·
2022
·
IF 0
Huan Qin,Haoyu Wu,Shu-Mao Zeng,Fan Yi,Si-Yong Qin,Yue Sun,Li Ding,Haihui Wang
Osmotic energy is a kind of blue energy that has recently been identified as an additional source of clean energy. Using a membrane-based reverse electrodialysis (RED) process, this blue energy can be obtained from acidic industrial wastewater with different proton concentration gradients. However, this process demands high-performance membrane that can withstand harsh environments, possessing the advantages of wide pH tolerance, high-temperature resistance and chemical stability, developing such membranes remain a challenge. Herein, we report a two-dimensional (2D) lamellar Ti 3 C 2 T x MXene membrane-based RED device for osmotic energy capturing from proton gradients. Such a membrane exhibits a typical surface-charge-governed ion transport feature. Moreover, the MXene membrane-based energy harvesting device holds the merits of outstanding pH and temperature resistance. It exhibits an output power density of 6.5 W/m 2 and also demonstrates stability over 200 h at pH = 0, which is 30% higher than the commercialization benchmark (5 W/m 2 ). The osmotic power density can be further enhanced to 11.1 W/m 2 at 330 K, demonstrating excellent thermal and chemical stability. This work can help better understand protons' transport behaviors in MXene membranes and open new avenues for applications in sustainable power conversion and wastewater treatment.
研究领域:
能源科学
·
材料科学
·
环境工程
·
化学工程
✓ 已验证
DOI
Industrial Chemistry & Materials
·
2023
·
IF 0
Jun Han,Wenrou Tian,Ye Miao,Najun Li,Dongyun Chen,Qingfeng Xu,Hua Li,Jianmei Lu
Coupling the effects of flexoelectricity with piezoelectricity has been proved to effectively harvest mechanical energy. In this study, a composition-graded core–shell structure (HAP@FAP) was prepared by surface-gradient F-doping in hydroxyapatite, which could introduce flexoelectricity by a built-in strain gradient. A flexoelectric-boosted piezoelectric response was demonstrated by piezoresponse force microscopy (PFM) characterization, showing that the piezoelectric constant of HAP@FAP was increased by 2.25 times via a lattice strain gradient induced by chemical heterogeneities derived from the unique composition-graded core–shell structure. Thus, the piezocatalytic activity of HAP@FAP for phenanthrene (PHE) degradation in soil was enhanced. This work provides a new strategy for the modification of piezoelectric catalysts for the remediation of organics-contaminated soils on industrial land.
研究领域:
材料科学
·
环境科学
·
物理化学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）