COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Qindan Zhang,Huajun Li,Chunying Zhu,Taotao Fu,Youguang Ma,Huai Z. Li
The combination of microfluidics with magnetism has led to the emergence of a new scientific domain known as micro-magnetofluidics. The present study aims to investigate the interfacial dynamics of ferrofluid droplet formation under magnetic field in a microfluidic T-junction. A non-uniform magnetic field was constructed by placing a permanent magnet at one side of the T-junction. Three typical flow regimes including the slug, slug-dripping transition and dripping flow were observed. The external magnetic field promotes the transition from the slug-dripping transition flow to the slug flow, prolongs the generation cycle of ferrofluid droplets and hinders the ferrofluid droplet formation. As the magnetic flux density increases, both the increasing rate of the length for the thread tip and the expanding rate of the dispersed neck decrease, and the peak value of the minimum width of the dispersed neck increases. The ferrofluid droplet size increases with increasing the magnetic flux density while decreases with increasing the two-phase flow rate ratio and the capillary number. A scaling law is proposed to predict the size of ferrofluid droplets, by taking the two-phase flow rate ratio, capillary number and magnetic Bond number into account.
研究领域:
物理学
·
流体力学
·
微流控技术
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 6
·期 1
·778-785
·
IF 3.84
Huajun Li,Yining Wu,Xiaoda Wang,Chunying Zhu,Taotao Fu,Youguang Ma
This paper is mainly focused on the investigation of the magnetofluidic control of the breakup of ferrofluid droplets in a symmetric Y-junction. The asymmetric breakup of the ferrofluid droplet or non-breakup with filtering the mother droplet into a desired branch to separate it from the satellite droplet was implemented by an external magnetic field. The breakup processes of ferrofluid droplets with and without the magnetic field were studied systematically. The influences of both the flow rate ratio between the continuous phase and dispersed phase and the magnetic flux density on the sizes of daughter droplets were determined. It was found that the attractive magnetic force shifted the mass center of mother droplet in the upstream main channel, which accordingly facilitated the asymmetric breakup of the droplet at the downstream Y-junction. A power function correlation for precisely predicting the sizes of daughter droplets was proposed by introducing the magnetic Bond number (Bom). Moreover, we also found that the controllable magnetic force could promote the pattern transition between the breakup and non-breakup of ferrofluid droplets.
研究领域:
微流体力学
·
材料科学
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Xin Gao,Shaoying Shi,Ziqin Ming,Yan Zhang,Ri Qiu,Yibo Ouyang,Jin Zhao,Jie Liu
Copper has extensive industrial applications. However, the susceptibility to corrosion makes it vulnerable in harsh environments. Bioinspired coating presents a novel approach to address copper corrosion. Bioinspired from lotus leaves and pitcher plants, this research endeavors to create superhydrophobic and ferrofluid-infused surfaces (FIS) on copper substrate. Firstly, a one-step electrodeposition method is employed to fabricate superhydrophobic surface on copper. Secondly, Fe 3 O 4 nanoparticles are sequentially modified with dopamine hydrochloride and dodecanethiol to endow surface hydrophobicity. Then, the modified Fe 3 O 4 is dispersed in oil to create a magnetic fluid, which is finally infused onto the superhydrophobic matrix, forming the FIS coating. Electrochemical testing confirms the high protective effect of the bio-inspired superhydrophobic and magnetic fluid composite coating against corrosion. The FIS coating exhibits a prominent low-frequency impedance modulus (7.73 × 10 6 Ω·cm²) even after immersion in NaCl solution for 60 d. Furthermore, the coating demonstrates an outstanding magnetic-driven self-healing capability, as evidenced by the minimal decrease in the |Z| 0.01 Hz value (remaining as high as 10 9 Ω·cm²) even after undergoing six cycles of scratching and self-healing process. This corrosion resistance can be attributed to the combined effects of the accommodating effect of superhydrophobic matrix and the self-healing property of the magnetic fluid under the magnetic field. This dually bio-inspired coating technology offers significant advantages for copper applications in harsh environments.
研究领域:
材料科学
·
生物学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2018
·
IF 4.946
Dezhi Yang,Guixiang Li,Lan Wu,Yaling Yang
A novel liquid-phase microextraction based on the ferrofluid was successfully applied for the extraction and determination of four phenolic compounds (bisphenol-A, bisphenol-AF, tetrabromobisphenol-A and 4-tert-octylphenol) in milks and fruit juices. In this study, a range of alkyl (C 4 –C 10 ) alcohols as the carrier liquid were used for the preparation of ferrofluids. The study showed that an appropriate chain length of alkyl alcohol may improve the extraction efficiency and maintain the integrity of ferrofluids during extraction, so 1-heptanol (C 7 ) was selected as the optimal carrier liquid. Specifically, the effects of various parameters on the extraction of phenolic compounds were investigated and optimized. Under the optimized conditions, the limits of detection were between 0.35 and 0.66 μg L −1 . The intra-day and inter-day precision (RSD %) for the analytes at 10 and 50 μg L −1 were in the range of 3.2–6.7 % and 2.9–7.1%, respectively.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2017
·
IF 4.421
Rui Ma,Taotao Fu,Qindan Zhang,Chunying Zhu,Youguang Ma,Huai Z. Li
This paper investigated the breakup dynamics of ferrofluid droplet in a microfluidic T-junction with the magnetic field. Droplet breakup types with permanent obstruction, part obstruction and without obstruction were observed. The droplet breakup processes with permanent and part obstruction could be divided into squeezing, transition and pinch-off stages. The minimum width of droplet neck could be scaled as power-law relationships with time for squeezing stage and with remaining time for the last two stages. The droplet breakup process without obstruction has only last two stages. The results show that the magnetic field could affect the dynamics of droplet breakup.
研究领域:
流体力学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2022
·
IF 4.132
Xiaoxiao Dou,Zhewen Chen,Xiaojian Cao,Chicheng Ma,Jianlin Liu
Magnetic fluid is a new type of smart material, which holds implications for highly enhancing the oil displacement efficiency. In the present study, we perform a comprehensive investigation to probe the influence of a magnetic fluid on the displacement efficiency in porous media under the action of magnetic force. First, the displacement efficiency is measured by a self-developed setup, where factors such as the magnet thicknesses, the volume of the fluid injected, the fluid injection speed, and the porosity of the sample are surveyed as controllable variables. Moreover, the experimental results are well verified by the scaling laws according to the principle of dimensional balance. Next, a numerical simulation is performed to explore the detailed displacement process. First, the magnetic force generated by the ring magnet is calculated. Then, the function curves of the displacement efficiency with respect to the controlling variables are validated by the numerical simulation. In addition, the numerical simulation also demonstrates the volume phase distribution, the pressure field, and the velocity field of the mixed fluid during the displacement process. The simulation results are in excellent agreement with the experimental data. These findings are beneficial for us to better understand the oil displacement with the aid of external fields, which also provide inspiration for the areas of microfluidics, diffusion of pollutants, microsensors, etc.
研究领域:
石油工程
·
材料科学
·
流体力学
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2024
·Vol. 36
·期 29
·2314004
·
IF 27.4
Jing Jiang,Chenglong Li,Chenhong Chen,Chuanqian Shi,Jizhou Song
Transfer printing techniques based on tunable and reversible adhesives enable the heterogeneous integration of materials in desired layouts and are essential for developing both existing and envisioned electronic systems. Here, a novel tunable and reversible adhesive of liquid metal ferrofluid pillars for developing an efficient magnetically actuated noncontact transfer printing is reported. The liquid metal ferrofluid pillars offer the appealing advantages of gentle contact force by minimizing the preload effect and exceptional shape adaptability by maximizing the interfacial contact area due to their inherent fluidity, thus enabling a reliable damage-free pickup. Moreover, the liquid metal ferrofluid pillars harness the rapid stiffness increase and shape change with the magnetic field, generating an instantaneous ejection force to achieve a receiver-independent noncontact printing. Demonstrations of the adhesive of liquid metal ferrofluid pillars in transfer printing of diverse objects with different shapes, materials and dimensions onto various substrates illustrate its great potential in deterministic assembly.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Magnetochemistry
·
2025
·Vol. 11
·期 4
·30
·
IF 2.5
Licong Jin,Jixian Yang,Qian Li,Xin Tian,Decai Li
In the paper, a hybrid magnetic fluid is prepared by adding carbon nanotubes to pure ferrofluid to improve its thermal conductivity. Furthermore, an electromagnet is used as magnetic source equipment, and the magnetic field strength in the air gap of the electromagnet is analyzed in theory, simulations, and experiments. A thermal conductivity measurement apparatus for magnetic fluid is established according to the transient hot-wire method. The effects of weight fraction and the length of carbon nanotubes, the external magnetic field strength, and the magnetic field duration time on the thermal conductivity of hybrid magnetic fluid are experimentally investigated. The results show that the thermal conductivity of the hybrid magnetic fluid is significantly improved by adding long carbon nanotubes (10–30 μm), and the thermal conductivity could be enhanced by 23.39% when its weight fraction is 1%. The magnetic field strength (41, 81, 122, 162 mT) and magnetic field duration time have little influence on the thermal conductivity of the hybrid magnetic fluid. The thermal conductivity of the hybrid magnetic fluid has good stability.
研究领域:
材料科学
·
热物理学
✓ 已验证
DOI
高影响因子
ACS Omega
·
2020
·
IF 2.87
Qian Li,Juying Zhao,Licong Jin,Decai Li
Kerosene-based ferrofluid (FF) loaded with multiwalled carbon nanotubes (MCNTs) is prepared and characterized to enhance heat conduction and furthermore for potential application in high-speed ferrofluid seals. The present study investigates kerosene-based ferrofluid loaded with MCNTs for the thermal conductivity and magnetization behaviors by varying temperature, weight fractions of MCNTs, and functional groups of MCNTs. The thermal conductivity is then measured by using a transient hot wire method, and magnetization behaviors are measured by using vibrator sample magnetometers. Microstructures among MCNTs and microstructures between MCNTs and magnetic nanoparticles in nanofluids are analyzed by optical microscopy and transmission electron microscopy. Experiments are carried out in the temperature range of 20–50 °C, MCNT weight fraction range of 0–1% for kerosene-based ferrofluid loaded with pristine MCNTs (p-MCNTs), MCNTs functionalized with carboxylic groups (MCNTs-COOH), and MCNTs functionalized with hydroxyl groups (MCNTs-OH). Results show that thermal conductivity and magnetization of FF + MCNTs nanofluids decrease with the increase in temperature. The addition of MCNTs increases the thermal conductivity and decreases the magnetization of the original ferrofluid, especially in the FF + p-MCNTs nanofluids. Furthermore, the addition of 1 wt % p-MCNTs increases the thermal conductivity and decreases the magnetization of the original ferrofluid by 12.47 and 7.73%, respectively. Moreover, the FF + 1 wt % p-MCNTs nanofluid can be stable for at least eleven weeks, which might be basically applied to high-speed ferrofluid seals.
研究领域:
材料科学
·
热物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WEAR
·
2025
·
IF 6.1
Zhijun CHEN,Qiusheng YAN,Jisheng PAN,Hanhao LIU,Kaiyuan LUO,Jingyuan ZHENG
In photocatalytic-assisted magnetorheological polishing(PMRP), both the opacity of the magnetorheological fluid and the non-magnetic properties of the photocatalyst limit the processing efficiency and quality of SiC wafers. In this paper, the magnetorheological fluid is prepared by using photocatalysts with different physical phases(liquid/solid) and properties(magnetic/non-magnetic), and then the friction chemical mechanism is carried out on SiC. The results show that the transmittance of the magnetorheological fluid and the distribution state of the photocatalyst synergistically cooperate to control the chemical oxidation rate of single-crystal SiC. When using magnetic particles with photocatalytic coatings for processing, the photocatalytic reaction spots can be effectively constrained and the SiC oxidation efficiency can be improved.
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
Engineering Applications of Computational Fluid Mechanics
·
2023
·
IF 6.1
Mohamed Boujelbene,Sohail Rehman,Sultan Alqahtani,Sultan Alshehery,Sayed M. Eldin
This study enlightens the magnetohydrodynamic Jeffery-Hamel flow under an inclined Lorentz force through a non-uniform conduit having slip at walls, which is frequently applied in geothermal applications, electronic cooling devices, and modern energy systems, etc. Therefore, the performance of a two-dimensional purely radial flow inside a converging-diverging channel is explored from the perspective of second law of thermodynamics for Carreau nanofluids. The intersecting walls of conduit are inclined with horizontal plane to construct a converging flow for negative angle (α<0) and a diverging flow for positive angle (α>0). Additionally, second law thermodynamic evaluation offers an effective method for improving thermal performance by reducing entropy production. To accomplish the main objective, rigorous physical theories and assumptions are implemented based on the passive control approach of Buongiorno's model. By applying distinctive modifications, the governing equations are renovated into a system of ordinary differential equations, which are solved numerically by a collocated technique based on finite difference code. Simple shear near the wall influences the flow configurations allow compression in a local flow topology in regions of divergent channel. The temperature profiles increase with sophisticated heat source and Brinkman number. Entropy is minimum and uniform with optimum channel angle and velocity slip.
研究领域:
工程热物理
·
流体力学
·
纳米科技
✓ 已验证
DOI
高影响因子
Nanoscale
·
2012
·Vol. 4
·期 5
·1598-1605
·
IF 5.914
Jing Liu,Yiwu Mao,Jianping Ge
Nonmagnetic polymer colloids have been assembled into colloidal photonic crystals in a ferrofluid by applying an external magnetic field based on the dipole–dipole interactions of “magnetic holes”. The photonic crystal disassembles immediately when the magnetic field is removed. The mechanism of assembly can be explained by two simultaneous processes: phase separation and colloidal assembly. In this work, increasing the size of the building blocks still produces colorful photonic crystals due to their 2nd order diffraction. With a larger building block, the magnetic response between the polymer colloids is greatly enhanced so that an instant and reversible assembly/disassembly can be realized in a much weaker magnetic field and lower ferrofluid concentration. Based on these investigations, a magnetically controlled photonic display unit has been fabricated, which works in a weak magnetic field, has stable reflection signals and possesses fast and reversible on/off switching of reflections.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）