PHYSICS OF FLUIDS
·
2022
·Vol. 34
·期 3
·
IF 4.98
Yuan Shuai,Zhou Mingyong,Peng Tao,Li Qiang,Jiang Fengze
Achieving rapid mixing of different liquids in a short distance is important in various biochemical applications. Herein, a novel planar mixer with staggered Z-shaped baffles is proposed. Numerical investigations are carried out to evaluate its mixing ability based on mixing quality and pressure drop when the Reynolds number (Re) varies from 0.1 to 50. The Lyapunov exponent, the Poincaré map, and the vortex visualization are conducted to comprehensively analyze the chaotic state and the mixing mechanism. Results show that the proposed mixer exceeds 0.9 mixing efficiency when 0.1 ≤ Re and Re ≥ 8. As Re ≥ 8, different vortex patterns appear by changing the inlet configuration. The disturbance for fluids induced by a vortex on the mass transfer surface is not only dependent on its intensity but also related to the position of the vortex/vortex leg. The proposed planar mixer, inducing a single vortex or vortex pair with different directions, presents different mixing performance when the Re varies from 8 to 50, from which the approach of the rotating vortex that can mainly improve the mixing quality is found. This well explains the chaotic mixing behavior observed in the planar mixer with Z-shaped baffles, which to date has not been studied before. Furthermore, the micromixer is fabricated, tested, and applied for luminol–peroxide chemiluminescence detection to characterize its performance.
研究领域:
流体力学
·
生物化学工程
·
微流控技术
✓ 已验证
产品关联
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Zhaoyang Su,Xing Li,Yanling Yang,Peng Du,Xiaobo Fang
Appropriate mixing conditions are always favorable during enhanced coagulation for the desirable performance. However, up to now, there are little studies systematically investigated the effects of mixing duration and intensity on coagulation–flocculation efficiency based on a comprehensive consideration. Different mixing intensity and duration were applied in coagulation and flocculation, respectively, using aluminum sulfate as the coagulant at a predetermined dosage where significant hydroxide precipitate occurs. Flocs formation, breakage and regrowth were monitored using a ‘turbidity fluctuation’ technique, photometric dispersion analyzer (PDA) measurement. In addition, the flocs images were in situ captured using a charged-coupled device camera to further the knowledge of flocs characteristics, such as fractal dimension and settleability. The results indicated that a slightly prolonged rapid mixing time (120 s) improved floc density with better settleability when the mixing intensity in coagulation stage was maintained at a central level. In contrast, a little higher mixing intensity (40.2 s –1 ) in flocculation stage induced more compact flocs, however, with smaller homogeneous size. The compensatory interaction of mixing conditions between coagulation and flocculation stages was verified. Particularly, this work was expected to provide a useful suggestion on optimizing coagulation and flocculation separately, and thus the desirable performance can be obtained by the optimized operational design.
研究领域:
环境工程
·
水处理技术
·
颗粒物去除
·
过程优化
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Yuanhang Jin,Yu Xie,Haipeng Zhu,Jiangpu Nan,Fenjuan Xiangli,Gongping Liu,Wanqin Jin
Separation of azeotropic mixtures is a typical energy-intensive process in chemical industry, in which pervaporation membrane process shows great potential in energy efficiency. However, the performance of commercial membranes such as polydimethylsiloxane (PDMS) is unattractive for practical application. Henein, for the first time, we employed microporous MAF-6 as a new filler incorporating into PDMS membrane for pervaporation separation of DMC/methanol azeotropic mixture. The resulting MAF-6/PDMS mixed-matrix membrane with the optimal filler size of 300 nm and filler loading of 12 wt% exhibited highly DMC permeability (651–811.5 Barrer) and selectivity (10.1–10.4) during 31 days continuous separation process, which fairly exceeds the state-of-the-arts membrane performance. A pervaporation-distillation coupled process was further proposed for the purification of DMC/methanol mixtures, showing 55.7 % of energy-saving compared with conventional distillation process.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICS OF FLUIDS
·
2024
·Vol. 36
·期 11
·
IF 4.1
Chen Xinkun,Zhai Junlong,Chen Xueye
The traditional lipid preparation methods are complex, time-consuming, and consume a large amount of reagents, increasing costs and difficulties. Although microfluidic technology is considered a promising solution, achieving controllable liposome production with a simple and inexpensive microfluidic mixing device remains an important problem. This paper presents a wall-type micro-mixer based on coastal zone fractals. Four parameters related to the geometric shape of the coastline fractal in the microchannel are used as design variables, and the mixing index is the objective function. Single-objective optimization numerical analysis of the primary wall-type fractal baffle micromixer under four Reynolds numbers conditions yields the optimal structural configuration. Visualization experiments verify the correctness and accuracy of the numerical simulation, and the optimized mixer is used to produce liposomes. The results show that the micro-mixer with the optimal double-sidewall cross arrangement enhances chaotic convection and improves mixing efficiency. At Re = 0.1 and Re = 100, the mixing efficiency reaches 99%, 50.44% higher than the reference design. By changing the relative flow rates of lipid and aqueous solutions, microfluidic blank liposomes with a particle size of 165.12 ± 11.6 nm and a polydispersity index of 0.35± are obtained. This wall-type fractal micro-mixer has broad application prospects due to its high mixing efficiency.
研究领域:
药剂学
·
生物工程
·
化学工程
✓ 已验证
DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2022
·Vol. 39
·期 12
·3323-3333
·
IF 3.146
Liu Dong-yan,Lou Wen-bo,Sun Shi-neng,Zhang Yang,Zhang Ying,Zheng Shi-li
The recovery of iron phosphate involves the addition of oxidizer to oxidize Fe 2+ in the spent LiFePO 4 (LFP) material to Fe 3+ and the agent commonly used is hydrogen peroxide (H 2 O 2 ). Nevertheless, H 2 O 2 has disadvantages of high price, easy decomposition and low utilization efficiency. In this manuscript, a facile method is proposed for efficient synergistic oxidation of Fe 2+ in spent LFP leachate with a mixture of oxygen and ozone. Specifically, we found by thermodynamic computations that the dominant oxidation groups of ozone during oxidation varied with acidity. The oxidation would produce a large number of iron-phosphate complex groups (Fe 3 H 6 (PO 4 )
3+ 4
, FeH 8 (PO 4 )
− 4
and Fe 2 HPO
4+ 4
) in the phosphorus-sulfur mixed acid system, leading to a paradoxical pH drop. The optimized conditions for H 2 O 2 oxidation were explored. It was determined experimentally that oxidation by gas mixture and O 2 belonged to the firstorder and second-order reactions with activation energies of 28.68 kJ/mol and 34.61 kJ/mol, respectively, which were both controlled by a mixture of chemical reaction and diffusion. The optimized oxidation method was finally determined by evaluating the cost and oxidation rate of the oxidizers. The results in this study offer a promising method for new low-cost and efficient Fe 2+ oxidation for industrial production.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Pei Xie,Kai Wang,Jisong Zhang,Yunpeng Hu,Guangsheng Luo
To obtain a high quality bromobutyl rubber product, a higher selectivity of brominated secondary allylic structure is necessary, but it is difficult to realize in traditional reaction devices. We developed a microreaction system and used microwater droplets as an extractant to in situ remove HBr, the catalyst of the isomerization side reaction, from the organic reacting solution to prevent converting brominated secondary allyl to brominated primary allyl and degradation of the polymer chain. The microreaction system contains two micromixers, including a membrane dispersion micromixer for dispersing microwater droplets in the butyl rubber solution and a cross-junction micromixer for blending butyl rubber and Br2 solutions. A volume adjustable delayed loop after the micromixers is used to carry out the reaction. The results show that 1 wt % water in the organic phase is satisfied to remove HBr, and 97% selectivity of brominated secondary allyl is successfully obtained under optimized operating conditions.
研究领域:
化学工程
·
聚合物科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2020
·
IF 4.473
Yu Ouyang,Ori Geuli,Qingli Hao,Daniel Mandler
Hybrid electrodes, which are made of a physical (electrical double layer) storage component and a chemical (battery-type) material, have shown great potential in battery–supercapacitor hybrid (BSH) devices. Here, we present an approach which is based on electrophoretic deposition (EPD) as a means of assembling a binder-free, high-performance BSH device. Ketjenblack (KB) used as the physical storage material and NiCo2O4 (NCO) as the chemical storage compound were dispersed in the presence of Ni2+. The latter assisted in positively charging the surface of both materials and thus resulted in similar deposition rates by EPD on nickel foam (NF). This enabled us to nicely control the NCO to KB ratio in the hybrid electrode and optimize its performance. In this binder-free hybrid electrode, the KB chains served as a fast electron path providing high conductivity for the NCO electroactive material. More importantly, the KB chains could remain in contact with NCO coping with the mechanical stress during the electrochemical reaction. As a result, the optimized hybrid electrode showed high specific capacity (460 C g–1 at 1 A g–1) and excellent cycling performance (82.5% retention after 15 000 cycles). The BSH device was assembled with the hybrid electrode (NF/NCO-KB) as positive and activated carbon as negative electrodes, and exhibited high energy density of 53.0 Wh kg–1 at power density of 746 W kg–1 and outstanding cycling performance of 88.6% retention after 10 000 cycles.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2024
·
IF 2.8
Yong Peng,Yanhao Shen,Junfeng Niu,Xiaoyu Han
In recent years, deep eutectic solvents (DESs) have emerged as environmentally friendly distillation entrainers. However, most research has focused on pure DESs, and developing new DESs remains challenging. This process requires significant time to screen suitable hydrogen bond donors and acceptors. This study explores a hybrid approach to enhance the efficacy of single DESs. Using the widely studied ethanol/water azeotropic mixture as a model system, Choline chloride (ChCl):urea (1:2, mol/mol) was selected as the benchmark entrainer. Among the 13 inorganic salts tested, CaCl 2 was chosen as an additive to prepare a hybrid entrainer (5 wt% CaCl 2 + 95 wt% ChCl:urea). Increasing the hybrid entrainer content from 0 to 36.9 wt% resulted in a 270% increase in relative volatility, outperforming pure DESs. This hybrid approach demonstrates potential to reduce ChCl:urea usage by 50%. Vapor-liquid equilibria were determined, with a good fit between experimental and theoretical data using the NRTL model.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Yali Guo,Xu Xing,Yanan Shang,Baoyu Gao,Lei Zhang,Qinyan Yue,Li Qian,Zihang Wang
To insight into the selective adsorption mechanism of fluoride in the bimetallic system, Fe-La or Al-La composites were comparatively embedded onto the cellulose/graphene hybrids (CG hybrids) to fabricate the Fe-La@CG hybrids or Al-La@CG hybrids for fluoride uptake with existing phosphate. The results showed that Al-La@CG hybrids were mainly in the amorphous nature, while Fe-La@CG hybrids have the identical diffraction peaks as compared with those of hydrated lanthanum oxides (HLO) and hydrated iron oxides (HFO). Fluoride capture by Al-La@CG and Fe-La@CG hybrids followed the similar tendencies with the pH altering, but the adsorption performance of Al-La@CG hybrids was better than that of Fe-La@CG hybrids at the same pH levels. Adsorption of fluoride onto Al-La@CG hybrids exhibited less sensitivity and high selectivity with existing phosphate as compared with that of Fe-La@CG hybrids, which further indicated that the Al-La@CG hybrids were more preferable for fluoride adsorption. The fraction areas of La-F and Al-F accounted for 79.1 % and 20.9%, which indicated that the fluoride onto the Al-La@CG hybrids was mainly based on the La species. Similarly, La-F in exhausted Fe-La@CG hybrids accounted for 55.6%, higher than that (44.4%) of Fe-F.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 7
·期 11
·2334-2347
·
IF 5.2
Bo Liu,Bin Ran,Chaozhan Chen,Liuyong Shi,Ya Liu,Huaying Chen,Yonggang Zhu
Homogenous mixing in microfluidic devices is often required for efficient chemical and biological reactions. Passive micromixing without external energy input has attracted much research interest. We have developed a high-performance 3D micromixer over a wide range of Reynolds number (Re) and viscosity, which was fabricated in a low-cost method of 3D printing. The characterization of the 3D printer was performed by measuring the surface roughness and fabrication error. The mixing mechanism and performance of the micromixer were investigated through numerical simulations and experiments. Influences of geometry parameters, including length, rotation direction and connection angle of helical elements, were also investigated. The mixing performance of the micromixer was studied over an ultra-wide range of flow rates from 0.3 to 70 000 μL min−1 (Re = 0.01–2333.3). The mixer presented an excellent mixing performance, with a mixing efficiency of more than 96.5% for water and more than 85.1% for solutions with viscosities nearly 13 times that of water. The micromixer can achieve rapid mixing with a mixing time of 883.7 μs for aqueous solutions. In addition, the high-performance micromixer was integrated into a versatile electrochemical detection platform to enhance enzyme-catalyzed reactions. The bare microelectrode array (μEA) on the detection platform has a wide linear detection range to sarcosine from 30 to 1000 μM with a limit of detection (LOD) of 9.7 μM. The highest sensitivity for sarcosine detection (281.7 μA mM−1 cm−2) and enhancement of current response up to 57.1% were achieved on the detection platform. This work broadens the scope of micromixer applications and sheds new light on the development of high-performance micromixers.
研究领域:
微流控技术
·
生物医学工程
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Huanhuan Shi,Kaixuan Nie,Bo Dong,Lemeng Chao,Fengxiao Gao,Mingyang Ma,Mengqiu Long,Zhengchun Liu
The amide condensation reaction is crucial for preparing biological probes with a polypeptide backbone. The traditional condensation reaction requires the monomer and condensing agent to be pre-mixed and activated by physical agitation mixing, which entail long time, require many reagents, and yield several by-products. In microfluidic mixing devices, the high specific surface area of microchannel enables traditional chemical reactions to be accomplished efficiently and quickly using only trace amounts of reagents in real time. This paper presents a serpentine mixing channel for the activation of amino acid monomers. A number of outward convex elliptical structures are introduced to both sides of the improved serpentine microchannel, creating a Dean vortex that increases the mixing efficiency at low Reynolds condition (90% at Re = 40). Effective monomer activation can be realized directly using a micromixing reactor and leads to less by-products as verified by ultraviolet spectroscopy and high-performance liquid chromatography analysis. The practicability of the micromixer is successfully tested by utilizing it as a microreactor for the real-time activation of amino acids for the in situ synthesis of polypeptide array at a flow rate of 300 μL/min ( Re = 40). The proposed micromixer has the potential to be an excellent alternative for conventional flask reactions and integrated in automated miniaturized biochip preparation systems.
研究领域:
生物化学
·
微流控技术
·
分析化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2021
·
IF 4.311
Xiaoming Luo,Ke Xu,Wanrui Li,Xin Huang,Limin He
In the case of fluid flow with a low Reynolds number, the internal fluid stratification can be easily observed after droplet coalescence, impeding rapid mixing of fluid. In this study, the capillary pressure difference is increased by adjusting the droplet size and the interfacial tension, so that a strong jet can be generated, resulting in a rapid mixing. Five distinct droplet mixing modes have been found. The phase diagram of the droplet mixing modes is obtained and the transition rule of the droplet mixing modes is established on this basis. A novel energy distribution model is employed to analyze the dependence between liquid bridge expansion and jet movement of two droplets. In addition, a criterion for evaluating the mixing efficiency of droplets is presented. The results presented in this paper provide a theoretical basis and practical guidance for realizing the efficient mixing of microfluids.
研究领域:
流体力学
·
微流体学
·
生物医学工程
·
界面科学
·
传质过程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）