ULTRASONICS
·
2018
·
IF 2.377
Di Xu,Feiyan Cai,Mian Chen,Fei Li,Chen Wang,Long Meng,Dehui Xu,Wei Wang,Junru Wu,Hairong Zheng
Precise manipulation of microparticles in microchannels is a primary technique for numerous lab-on-a-chip bioengineering research and applications, as it determines the chip’s functions and analytical results. Acoustic manipulation, using the acoustic radiation force, is a compact, versatile and contactless manipulation technique, which can be easily integrated with other microfluidic components. It is our main purpose to report the effect of boundary condition of a cylindrical microfluidic cavity on the acoustic particles’ manipulation. A device consisting of a cylindrical cavity in a silicon wafer with three kinds of top boundary conditions (rigid, soft, and imperfect rigid boundary) has been built. The corresponding distributions of acoustic radiation force are analyzed analytically and numerically. Experiments are performed with 2.5 μm radius polystyrene microspheres in the cavity covered by three reflective layers (340 μm-thick glass, 400 μm-thick PDMS , and 660 μm-thick glass film), respectively, which specify the three different boundary conditions at the top of the cavity. It is demonstrated that the boundary condition of a cavity influences the acoustic radiation force and the stable positions of particles, and this is in agreement with the theoretical predictions. Thus, the effects of boundary conditions need to be considered for precise acoustic manipulation.
研究领域:
生物工程
·
声学
·
微流体技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Jian Zhang,Junkai Chang,Yiming Yin,Jianlong Dai,Yunfei Ge,Bo Zhao,Nan Sheng,Chunyu Zhu
The development of practical high temperature metallic phase change macrocapsules still faces difficulties, because metallic phase change materials undergo volume expansion during phase transformations, which can lead to outer shell rupture. When a core made of stacked metal powders is used, a cavity is eventually formed inside the capsule that acts as a cushion for volume expansion, thus reducing the risk of capsule rupture. However, the cavity will weaken the thermal storage capacity of the capsule, and in order to obtain a capsule with good thermal storage capacity and long-time cycling stability, it is necessary to find a suitable cavity volume of the capsule. In this paper, Cu powders are used as the core raw material, which are spherelized into millimeter level spheres, and the Cu powder spheres are isostatically pressed using an isostatic presser under different pressures to achieve the optimization of the cavity volume by reducing the gap between the powders. The high strength α-Al 2 O 3 is selected as the shell, and sintering additives MgO and SiO 2 are doped into the raw material, and the Cu@MgO-SiO 2 /Al 2 O 3 capsules are prepared after two-step sintering treatment. The material properties and thermal storage properties of the capsules are investigated in detail, which have strong thermal storage properties, for example, in the temperature interval of 1000–1100 ℃, capsules with a core-shell structure (named as [email protected] –100 MPa, prepared with initial diameter of Cu core of 9 mm, shell thickness of 1.5 mm, and isostatic pressing under 100 MPa to the core precursor) exhibit a high heat storage density of 222 J/g and 841 MJ/m³. In addition, we conduct melting-solidification cycle tests, which confirms the excellent durability of the capsules. The comprehensive results show that the Cu@MgO-SiO 2 /Al 2 O 3 macrocapsules possess strong thermal storage capacity and can be used as effective thermal storage materials, especially in advanced high temperature thermal storage systems.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2025
·
IF 2.6
Jinran Chen,Xiurui Ke,Zhou Zhou,Wenqi Ye,Hong Liu,Wei Zhang,Xiaohong Liu
We report the fabrication of a substrate with cavity-nanorods and decorated with Ag-nanoplates (C-NR@Ag). The cavities on the substrate are formed by metal assistant chemical etching, and the Ag-nanoplates in the cavities by galvanic cell deposition enhance the SERS performance effectively. Analytes in solution are adsorbed on Ag-nanoplates and located in hot spots, which enhance the SERS performance effectively. The enhancement factor of the Ag-nanoplates decorated on nanorod cavities is calculated to be 3.6 × 106, which is about 3 fold higher than that on the nanorods. The C-NR@Ag substrate is able to detect polychlorinated biphenyls (PCBs) with the lower limit of detection at 1.0 × 10−12 M. Additionally, due to the semi-volatile nature of PCB-77, the lower limit of detection of the C-NR@Ag substrate for PCB-77 was 1.0 × 10−11 M by the non-contact collection method. These results present a novel approach towards enhancing SERS performance and facilitating the rapid detection of PCB-77.
研究领域:
材料科学
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环境科学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Applied Materials Today
·
2025
·
IF 6.9
J. Zhao,P.C. He,J.H. Yang,Y.J. Liu,S. Li,J.P. Qu,Z.J. Cheng,J.L. Mo
Efficient drag reduction is critical for improving the energy efficiency of underwater vehicles, where a significant portion of propulsion energy is consumed in overcoming hydrodynamic resistance. When a superhydrophobic surface impacts water at a sufficient velocity, a streamlined cavity forms, effectively minimizing drag. However, at lower initial impact velocities, the cavity dissipates rapidly due to static water pressure and flow separation, leading to increased drag and reduced velocity. Numerical simulations using STAR-CCM+ reveal that cavity dissipation enlarges the flow separation zone at the sphere’s tail, significantly increasing pressure-induced drag. To enhance cavity stability and sustain drag reduction, this study proposes a bioinspired strategy that integrates hydrophilic strips onto superhydrophobic steel spheres via spraying and laser processing. The results demonstrate that the superhydrophobic/hydrophilic heterogeneous structure effectively anchors the gas-liquid-solid three-phase contact line, traps air bubbles, and stabilizes the cavity. Compared to fully coated spheres, localized hydrophilic strips (applied only at or above the equator) exhibit superior cavity stabilization, leading to prolonged drag reduction. Further optimization reveals that when the width and spacing of the hydrophilic strips are both 0.25 mm, the cavity remains most stable, achieving a maximum drag reduction efficiency of 63.3%. This study presents a scalable, cost-effective surface engineering approach for stabilizing underwater cavities, providing valuable insights into next-generation drag reduction technologies for underwater vehicles and robotic systems.
研究领域:
材料科学
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流体力学
·
仿生学
✓ 已验证
产品关联
DOI
高影响因子
Small Structures
·
2025
·
IF 11.3
Tian Li,JiaTong Li,DanDan Zhi,Jinzhe Li,Wenting Deng,RunHua Zhang,Renchi Qin,Qing Qi,Chul B. Park,Li Ma,Fanbin Meng
In response to the increasing need for high-performance microwave absorption materials (MAMs), this study introduces a multiaxis electrospinning method for synthesizing graphene-based aerogel microspheres (GAMs) aimed at broadband microwave absorption (MA). The micro/nanostructures and shell configurations of GAMs are effectively regulated and controlled to establish a predictable structure-properties relationship via establishing equivalent electromagnetic (EM) models. The computational simulations results of the structure–property relationship are employed as guidance to evaluate the effects of structural features, like hollow structures and multilayered shells. The analysis reveals that enhancing the hollow cavity optimizes impedance matching and promotes MA performance. Utilizing these insights, the fabricated hollow GAMs (HGAMs) achieve an effective absorption bandwidth (EAB) of 8.1 GHz and an optimal reflection loss of −34.8 dB at 3.3 mm thickness. Further simulations involving various hierarchical structures of GAMs arranged into mono/bilayer arrays investigate the group coupling effects on MA performance through the synergistically absorptive, interferential, and resonant attenuation mechanisms. Actual MA performance examination using an arch method on HGAM bilayer arrays confirms the simulations, achieving an EAB of 15 GHz at a thickness of 7 mm. Consequently, this approach demonstrates a promising avenue for developing lightweight, nanostructured MAMs suitable for advanced applications.
研究领域:
材料科学
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电磁学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2025
·
IF 4.5
Bojun Zhang,Weigui Fu,Guorui Zhang,Hao Wang,Xiaonan Cui,Meixiu Sun,Yiping Zhao,Li Chen
Cavity ringdown spectroscopy (CRDS) is a laser absorption technique that quantifies endogenous volatile organic compounds (VOCs) associated with diseases or metabolism. Accurately measuring breath isoprene at a wavelength of 226.56 nm via CRDS is challenging due to interference from high levels of exhaled acetone. In this work, an ultra-sensitive breath analysis system was developed that integrates gas separation membrane technology with CRDS for precise quantification of isoprene. Polyvinylidene fluoride (PVDF) hollow fiber membranes were dip-coated with polydimethylsiloxane (PDMS) to separate isoprene from acetone effectively. Proton transfer reaction mass spectrometry (PTR-MS) demonstrated that the optimal composite membrane coated with PDMS for 5 min (M 5 ), retained 91.43 % of acetone. When a mixed gas sample (isoprene 500 ppbv, acetone 1000 ppbv) was directly introduced into the CRDS system, the detected concentration of isoprene was 545.24 ± 18.73 ppbv. After M 5 separation, the isoprene concentration decreased to 497.69 ± 7.38 ppbv, reducing the relative error from 9.05 % to 0.46 % and enhancing the accuracy of isoprene detection. This study explores the integration of membrane separation with CRDS for real-time monitoring of simulated exhaled isoprene. The developed membrane-based CRDS system offers potential applications in biomarker validation, sensitive and accurate clinical diagnosis and long-term monitoring.
研究领域:
分析化学
·
医学诊断
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Qinglei Sun,Yang Peng,Hao Cheng,Yun Mou,Zizhou Yang,Dandan Liang,Mingxiang Chen
The development of three-dimensional kaolin-based materials cavities for direct plated copper (3DPC) ceramic substrates has great promising in hermetic and ultraviolet light emitting diodes electronic packaging field. In this study, suspensions with kaolin clay solids content of 24–32 vol% and polyacrylic acid were used for direct ink writing (DIW) technique to fabricate 3DPC. Experiments results showed that the stability and extrudability of kaolin suspensions related to their zeta potential and rheological properties, respectively. The zeta potential absolute values had little variation with the increase of kaolin solids content and characterized that kaolin particles were dispersed adequately in colloidal suspensions . Rheological and thixotropic tests showed that the 32 vol% kaolin solids content suspension with good fluidity and viscoelastic properties was suitable for DIW. The 3DPC prepared using this suspension can maintain basically primal appearance with little slumping. Mechanical properties such as compression, flexural and bonding strengths of the cured 32 vol% kaolin solids content suspension were also conducted. Processing kaolin suspensions via DIW presents opportunity for integrated packaging of electronics chips.
研究领域:
材料科学
·
电子封装技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Hong Chen,Min Sang,Yucheng Pan,Shilong Duan,Yuan Hu,Xinglong Gong
Developing devices emphasizing safety protection is becoming increasingly important due to the widespread occurrence of impact damage and thermal hazards. Herein, the F-SSG/TPU-based circular cavity structure (FC) is developed through a convenient and efficient template method, which can effectively achieve anti-impact and thermal insulation for protection. The flame-retardant shear stiffening gel/thermoplastic urethane (F-SSG/TPU) is synthesized through the dynamic interaction between the SSG, TPU, and modified ammonium polyphosphate (APP@UiO-66-NH2) by thermo-solvent reactions. The developed FC can dissipate the impact force from 4.19 to 0.99 kN at 45 cm impacting heights, indicating good anti-impact performance. Moreover, the thermal insulation test demonstrates that the FC achieves a temperature drop of 76 °C at 160 °C attributed to the unique cavity structure design. Under the continuous shock of high-temperature flame, FC remains intact, and its performance is almost undamaged. These results elaborate that the designed FC can effectively resist various damage, such as high-temperature shock and collision. Then, a wearable wristband integrated with FC is developed which exhibits superior impact resistance and heat insulation properties compared with commercial wristbands. In short, this cavity structure based on high-performance F-SSG/TPU material shows promising potential applications in the protection field.
研究领域:
材料科学
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工程学
·
安全技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITES PART B-ENGINEERING
·
2019
·
IF 6.864
Zhiming Deng,Yue Li,Hao-Bin Zhang,Yu Zhang,Jia-Qi Luo,Liu-Xin Liu,Zhong-Zhen Yu
Lightweight and high-performance microwave absorption materials with wide effective bandwidth are highly required due to the increasingly severe electromagnetic radiation. It is now still imperative to elaborately tune the constituents and microstructures of absorbers for improving microwave absorption capability over wide frequency ranges. Herein, sulfonated polystyrene@Fe(OH) 3 @polydopamine (SPS@Fe(OH) 3 @PDA) microspheres are firstly synthesized with ferric sulphate and dopamine as precursors of Fe(OH) 3 and amorphous carbon , and then thermally annealed at 600 °C to generate lightweight Fe@C hollow microspheres. The thermal annealing effectively decomposes SPS templates to gases, and carbonizes the PDA shell to amorphous carbon, which also reduces the ferric irons to magnetic Fe nanoparticles via the carbothermal reduction reaction. Interestingly, the microwave absorption performances of the Fe@C hollow microspheres are obviously improved by increasing the cavity sizes. The Fe@C hollow microspheres with the largest cavity of 780 nm exhibit the broadest effective absorption bandwidth of 7.5 GHz and the superior maximum reflection loss of −37.7 dB. These outstanding performances are attributed not only to the favourable synergistic effect of dielectric and magnetic losses, but also to the optimized hollow structure enhancing the attenuation capability and improving impedance matching. This work provides an efficient approach for designing and fabricating high-performance and broad-band microwave absorbers with tunable peak frequency.
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 MEMBRANE SCIENCE
·
2019
·
IF 7.015
Zhuliu Xiao,Binghua Zhou,Jirong Wang,Cai Zuo,Dan He,Xiaolin Xie,Zhigang Xue
Tailor-made star polymers comprised of cross-linked cores containing polymeric pseudo-crown ether cavities and linear poly(ethylene oxide) (PEO) arms are designed via cation template-assisted cyclopolymerization. The pseudo-crown ether cavities in cross-linked cores can coordinate with alkali metal cations and offer more cation diffusion channels. Moreover, the functional linear PEO arms are beneficial to the conductivity of cations and increase the compatibility with the PEO matrix. By selecting monomers with different chain lengths and cation templates, the tailor-made star polymers can be employed as efficient conductors for lithium-ion, sodium-ion, and potassium-ion batteries. The lithium-ion conductivity of the solid-state polymer electrolytes obtained from a potassium cation template and poly(ethylene glycol) dimethacrylate (PEGDMA750) monomer (K-SPE750-Li) is 2.82 × 10 -5 S cm -1 at 20 °C. Furthermore, the cell of Li|K-SPE750-Li|LiFePO 4 shows stable cycling performance and a good rate property.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
POLYMER TESTING
·
2021
·
IF 4.282
Bujin Liu,Jun Gu,Tuanhui Jiang,Rong Deng,Jingkui Yang,Xiangbu Zeng,Chun Zhang,Li He,Wei Gong
The morphology, size and surface roughness of the nucleating agent significantly affect the nucleation effect for foaming in the polymer. In this work, four nucleating agents with different morphologies, namely DE, MS, OMMT and β- CD as heterogeneous nucleation agents were selected for a polypropylene (PP) foaming injection molding process to explore nucleation mechanism. A theoretical assumption (cavity nucleation) in polymer foaming had been put forward about how to enhance the efficiency of bubble nucleation based on classical nucleation theory (CNT). Subsequently, the cavity nucleation was validated by chemical core-back injection foaming molding and in-situ visualization and elaborated by establishing a formula. Finally, designed petals shape particles as nucleating agents to further test this theory. The confirmation of this theory effectively improved the nucleation efficiency and foaming quality, which has important guiding significance to the development of lightweight products.
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
Nanomaterials
·
2021
·Vol. 11
·期 12
·3196
·
IF 5.076
Jihua Xu,Jinmeng Li,Guangxu Guo,Xiaofei Zhao,Zhen Li,Shicai Xu,Chonghui Li,Baoyuan Man,Jing Yu,Chao Zhang
The focusing field effect excited by the cavity mode has a positive coupling effect with the metal localized surface plasmon resonance (LSPR) effect, which can stimulate a stronger local electromagnetic field. Therefore, we combined the self-organizing process for component and array manufacturing with imprinting technology to construct a cheap and reproducible flexible polyvinyl alcohol (PVA) nanocavity array decorating with the silver nanoparticles (Ag NPs). The distribution of the local electromagnetic field was simulated theoretically, and the surface-enhanced Raman scattering (SERS) performance of the substrate was evaluated experimentally. The substrate shows excellent mechanical stability in bending experiments. It was proved theoretically and experimentally that the substrate still provides a stable signal when the excited light is incident from different angles. This flexible substrate can achieve low-cost, highly sensitive, uniform and conducive SERS detection, especially in situ detection, which shows a promising application prospect in food safety and biomedicine.Keywords:surface-enhanced Raman spectroscopy;localized surface plasmon resonance;flexible SERS substrate;cavity
研究领域:
材料科学
·
纳米技术
·
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）