iScience
·
2022
·
IF 6.107
Peiliu Li,Xianfu Huang,Ya-Pu Zhao
Viscous fingering is an extensively observed phenomenon in porous media or Hele-Shaw cells. In general, this instability is particularly difficult to control for given fluids and geometries. Therefore, investigating a control method of viscous fingering is quite attractive. Here, we present that electro-visco-fingering (EVF) in fluids with different relative permittivity shows a controllable performance under electric fields. The theoretical model is established from the perspective of force analysis to indicate that active control of EVF is achieved by the competition between the Maxwell stress jump and hydrostatic pressure gradient. In addition, an Electric Control number (E C ) is adopted to characterize the electric effect on EVF and experimentally confirmed for broad ranges of flow rates and voltages. Unlike the electro-osmotic flow, this method shows a considerable achievement in energy efficiency. Our work provides a new way to actively control viscous fingering and opens new routes for applications of interfacial instabilities.
研究领域:
流体力学
·
应用物理
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 6
·517
·
IF 4.4
Yunyu Sun,Hao Wang,Jiwei Jiang,Hui Zhang,Limei Liu,Keying Zhang,Bo Song,Bin Dong
Inspired by the collective behaviors of active systems in nature, the collective behavior of micromotors has attracted more and more attention in recent years. However, little attention has been paid to the collective behavior of the immobilized micromotor, i.e., the micropump. In this paper, a unique pentacene-based micropump is reported, which demonstrates dynamic collective behavior activated by white light irradiation. The light irradiation may generate the photochemical reactions between pentacene and water, leading to the electroosmotic flow. As a result, this micropump is capable of pumping the surrounding solution inward along the substrate surface based on the electroosmosis mechanism. Intriguingly, the inward pumping causes the agglomeration of the tracer particles on the surface of the micropump. In addition, the aggregation can migrate following the change in the light irradiation position between two adjacent micropumps. Based on the aggregating and migrating behaviors of this pentacene-based micropump, we have achieved the conductivity restoration of the cracked circuit.
研究领域:
材料科学
·
生物仿生学
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Zhao Cui,Meng Zhang,Yang Yuan,Hui Jia,Huu Hao Ngo,Jie Wang
The focus of this study is on the enhanced concentration effect of the pump effect in forward osmosis (FO) and electroosmotic integrated chip. The study investigates the strengthening effect of the FO process, driven by the pump effect, on the electroosmotic flow process under the same energy consumption, using low-concentration heavy metal ions (Cr 3+ ) as the target enrichment. In the chip system, the pump effect, caused by capillary pressure difference, successfully replaces the osmotic pressure of the draw solution as a new driving force for the FO process. By adjusting the size and number of channels and avoiding errors, the study achieves the highest efficiency of the FO process in the chip, concentrating Cr 3+ from 1.26 × 10 −4 mol/L to 8.01 × 10 −4 mol/L (6.4 times) within 32 min. Excluding the influence of the electrokinetic (EK) limit of low-concentration samples, the concentration efficiency of an individual electroosmotic chip in this study is positively correlated with cross-nanochannel voltage (V cn ). The integrated FO and electroosmosis chip reduce the duration required to concentrate 50 mL Cr 3+ sample to the limit from 90 min to 16 min (5.6 times) compared to the single electroosmotic process. Furthermore, a series of Cr 3+ samples with concentrations below the detection limit of the UV–vis spectrophotometer were concentrated and detected by the integrated chip. The results indicate that the concentration limit of the FO-electroosmotic integrated chip for samples can increase the detection limit of Cr 3+ from 1.37 × 10 −4 mol/L to 3.67 × 10 −6 mol/L.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
·
2023
·
IF 5.2
Shuai Yuan,Mingyong Zhou,Xijiang Liu,Bingyan Jiang
The coupling of pressure-driven flow (PDF) and electroosmotic flow (EOF) has been widely applied in the field of microfluidics. However, the adverse effects of pressure induced by PDF on EOF in a confined space cannot be ignored. Herein, the interactions of these two streams when the Reynolds number ( Re ) varies from 0.1 to 10 are systematically explored through numerical simulations to gain an in-depth understanding of the mechanism of the pressure effect on mass species transport and to generate optimal separation of samples. The simulation results show that the length of the sample increases linearly and the molecular diffusion is accelerated due to the pressure effect caused by the EOF channel structure and PDF extrusion, which reduces the separation quality and even leads to the failure of electrophoresis . However, the deformation of the sample cannot be effectively resisted by increasing the applied voltage . A better separation effect can be obtained only when Re =0.1. To surmount the above disadvantages, a novel porous polymer plug with pores smaller than 5 μm that provides a region that has high flow resistance but allows the electromigration of charged analytes is established in the EOF channel. The experimental results show that this plug can effectively neutralize the EOF outlet pressure when Re ≤5. The shape of the sample is not distorted and the maximum gray values decreased by 26%, 30% and 49% respectively in 7 s when Re =0.1, 1 and 5, which are much better than the results without the plug.
研究领域:
微流控技术
·
分析化学
·
生物工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2018
·
IF 6.042
Ruo-Can Qian,Jian Lv,Yi-Tao Long
Recently, a variety of strategies have been developed for single-cell detection. However, the precise probing of the given area at single-cell level is still a challenge. Here, we put forward a rapid and targeted imaging approach for the mapping of subcelluar domains, which realizes the precise injection of multifluorescence into a single living cell via an ultrasmall quartz capillary nanopipette (∼100 nm) and can successfully transport different fluorescent probe molecules to the pointing subcellullar area around the tip in the cytoplasm within 20 s. This method is also applied for monitoring the loss of intracellular mitochondrial membrane potential under the treatment of metformin in a single MCF-7 breast cancer cell. The major driven force in the nanopipette, electroosmotic flow, is evaluated by a theory calculation method and finite element simulations, and the solution indicates a confined solute distribution profile around the tip within the working range. Overall, the nanopipette approach realizes the precise and simultaneous delivery of multiple probe molecules into the single living cell through the electroosmotically modulated, nondestructive, and one-step injection, which is especially powerful and convenient for multichannel single-cell imaging and monitoring, indicating favorable potential for understanding, monitoring, and controlling the biological processes from the single cell to subcellular organelles.
研究领域:
细胞生物学
·
生物物理学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2025
·
IF 6.7
Xin Qian,Lan Xia,Baian Ji,Yike Huang,Zhining Xia
To improve separation efficiency and address the adverse effects of electro-osmosis, a coated capillary was used to shield the electroosmosis. A nanoflow pump was used to control the flow of the electrophoretic medium, thereby extending the time of the electrophoretic action. Furthermore, by using a coated capillary that is only 10 cm long as the separation column, the electric field strength could reach as high as 250 V/mm. These strategies strengthened the interaction between the enantiomers and the chiral selector, thus enhancing the resolution of enantiomers. As a result, complete separation of the amlodipine enantiomers could be achieved by halting the electrophoretic medium. Further extending the duration of flow stoppage can increase the resolution several-fold. The method established in this study exhibits excellent accuracy and precision. Despite experiencing a long period of flow stoppage, the relative standard deviations of both migration time and resolution remain less than 2%. This method not only remarkably enhanced the resolution of amlodipine enantiomers but also demonstrated broad applicability in separating other chiral enantiomers, particularly for those substances that are difficult to separate using conventional capillary electrophoresis.
研究领域:
分析化学
·
药物分析
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Lei Liu,Ke Zhang
Developing novel methods for the removal of heavy-metal ions from wastewater with low costs, special selectivity and high efficiency is quite important in water restoration and comprehensive ecological improvement. In this work, a nanopore-based strategy was suggested and related segregation apparatus was built to separate multiple heavy-metal ions in water by selective complexation. The results indicated that the prioritization of the selecting order for the complexing agent (thiacalix[4]arene-p-tetrasulfonate (TCAS)) to heavy-metal ions was Cu(II) > Cd(II) > Pb(II) > Ba(II). Meanwhile, higher driven voltage corresponded to a faster separation speed, while it could cause the decomposition of complexed heavy-metal ions when excessed the threshold. On the other hand, pH value would affect the hydrolysis of heavy-metal ions, the complexation of the calixarene to the heavy-metal ions and the speed of the electroosmotic flow. In our experiments, the maximum separation efficiency was achieved when the driven voltage was 1.5 V and the pH value was 5.0, corresponding to the best separation rate of 94.8%, 95.2%, 92.8%, 93.6%, for Cu(II), Cd(II), Pb(II) and Ba(II), respectively.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2015
·
IF 4.169
Qifeng Fu,Xiuju Li,Qihui Zhang,Fengqing Yang,Weili Wei,Zhining Xia
Electroosmotic flow (EOF), which reveals the charge property of capillary inner surface, has an important impact on the separation performance and reproducibility of capillary electrophoresis (CE). In this study, a novel, facile and versatile method to achieve diverse and controllable EOF in CE was reported based on the co-deposition of mussel-inspired polydopamine (PDA) and branched polyethyleneimine (PEI) on the capillary inner surface as the hybrid functional coating. After these PDA/PEI co-deposited columns were reinforced by the post-incubation of FeCl 3 , various magnitude and direction of EOF in CE could be easily achieved by varying a number of preparation parameters, including the mass ratio of DA/PEI and the molecular weight of PEI (including PEI-600, PEI-1800, PEI-10000 and PEI-70000). The separation effectiveness and stability of the hybrid coated columns were verified by the analysis of aromatic acids and aniline derivatives. The results showed that the controllable and diverse EOF was important in enhancing the separation performance of the analytes. The baseline separation of all the five aromatic acids can be achieved in 7 min with high separation efficiency by using the PDA/PEI-600 co-deposited column with the mass ratio of 6:1. On the other hand, with the PDA/PEI-70000 co-deposited column with the mass ratio of 6:1, the aniline compounds were easily baseline separated within 10 min. By contrast, using the bare and PDA coated columns, the migration of the aromatic acids was very slow and the baseline separation of the aniline compounds cannot be obtained. Moreover, the co-deposited columns showed long lifetime and good stability. The relative standard deviations for intra-day, inter-day and capillary-to-capillary repeatability of the PDA/PEI-600 co-deposited column with the mass ratio of 6:1, which was reinforced by the post-incubation of FeCl 3 , were all lower than 5%.
研究领域:
分析化学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED ENERGY
·
2020
·
IF 8.848
Yulin Lv,Feng Gong,Hao Li,Qiang Zhou,Xinlin Wu,Wenbin Wang,Rui Xiao
Low-grade energy harvesting from the ambient environment promises to relieve the energy shortage in the remote regions or emergency needs. The reported materials employed for low-grade energy harvesting requires costly raw materials and highly technical skills, hindering the applications in isolated regions or after natural disasters. Herein, we report the use of commercial air-laid paper and carbon ink to harvest electrokinetic energy in the capillary flow. The paper-based electrokinetic power generator with size of 6 cm × 1 cm could continuously generate an output voltage of 0.35 V and current of 33.9 μA in the ambient condition (20 °C and 50% Relative Humidity). The output power could maintain for over 120 h. When connected in series and in parallel, the power generator with excellent flexibility could power some common electronic devices in the atmosphere, such as light-emitting diode, electronic calculator and watch. This work offers a rational approach to employing low-cost materials for ambient energy harvesting, thus advancing the application in portable and wearable electronic devices.
研究领域:
能源科学
·
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2019
·
IF 3.858
Jiannan Sun,Shiwei Yang,Heyong Cheng,Yuanchao Wang,Jinhua Liu
Further development of capillary electrochromatography (CEC) is to some extent restricted by column technology. Packed capillary columns are most commonly used in CEC because of higher sample capacity and higher sensitivity than open tubular columns, and better reproducibility and uniformity than monolithic columns. Fritting is the core component for the fabrication of packed capillary columns. Therefore various fritting technologies attract continuous attention from analytical community. A convenient fritting method was developed in this study. In contrast to the reported single-particle fritting, this method applies a multi-particle fritting technology to hold stationary phase in capillary columns. Several large porous particles smaller than the column internal diameter were tapped in and immobilized in inlet and outlet of the packing material bed due to direct and indirect keystone effect. Except the smallest permeability by the sintered frit and the lowest breaking pressure by the single-particle frit, EOF mobility and peak dispersion of the multi-particle frit were at the same levels with the formers. In addition, all the three frits avoided bubble formation. It demonstrated that the multi-particle frits met the general requirements of permeability, mechanical resistance and efficiency for packing capillary microcolumns as well as the sintered frits and the single-particle frits. Thus, peak efficiency around 4.3 μm plate height (approximately 232,560 plates per meter) was obtained by multi-particle fritted capillary columns with electrokinetic packing, compared to 6.5 μm plate height by single-particle fritted columns with slurry pressure packing. In particular, the multi-particle fritting was simpler, faster, and more reproducible than the sintered fritting, and the multi-particle fritting was suitable to pack capillary columns of various capillary bore sizes owing to rich commercial resources of fritting particles of various diameters. Multi-particle fritted columns offered satisfactory run-to-run and column-to-column reproducibilities for retention factor, plate height and peak area (precisions of 4.1–9.3% for 10 replicated columns, and precisions of 0.9–3.1% for 30 replicated trials). They also had consistent CEC performance (differences of 1.1–3.9% between the first and 31 st day) during a lifetime more than one month. Application examples in packing capillary columns of 75 and 100 μm i.d. and CEC analysis of sixteen polycyclic aromatic hydrocarbons prove the diversity and reliability of the multi-particle fritting in column technology.
研究领域:
分析化学
·
分离科学
·
色谱技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2016
·
IF 2.632
Qiang Ren,Jun Chen,Fuqiang Chu,Jian Li,Qiang Yu,Dun Wu,Jianbo Fang
A kind of novel nanocoating based on star polymers and graphene was developed. The hydroxyl functionalized star polymers were synthesized by Activators Regenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET ATRP) using core-first approach. The branching behavior, copolymer composition and glass transition temperature was characterized clearly. Graphene/star polymer coating shows lower conductive percolation threshold values relative to linear analog. Transmission electronic microscopy verified the better dispersion of graphene sheet in star polymer matrix than linear polymer matrix. Rheological tests revealed that the increase of viscosity of star polymer solution aroused by addition of graphene was much weaker compared to that of linear counterpart. Star polymer based coating exhibit very short tack-free time and superior impact resistance. All the results demonstrate that star polymer is a good candidate to fabricate graphene filled nanocoating with advantages in performance as well as processing.
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
TALANTA
·
2013
·
IF 3.498
Si Li,Jing-Yu Dong,Chen-Gang Guo,Yi-Xin Wu,Wei Zhang,Liu-yin Fan,Cheng-Xi Cao,Wei-Bing Zhang
A simple capillary array IEF device was developed for high resolution and micropreparative separation of trace amounts of proteins. Based on quasi-chip-scale manufacturing, the specific capillaries (600 μm i.d., 1200 μm o.d. and 20 mm length) were integrated with the miniaturized polymethyl-methacrylate electrode trays. Electroosmotic flow was suppressed effectively by modified cross-linked polyacrylamide coating, and instability of IEF was addressed using the designed concentration of electrolytes via moving reaction boundary theory. As a prototyping, the resolution, reproducibility, throughput, speed and linearity of pH gradient were systemically evaluated with model proteins. The results revealed the following advantages: (i) the reproducibility of array was assessed as RSD values of 0.95% (intra-day) and 2.88% (inter-day); (ii) IEF could be completed in 20 min with up to 400 V/cm electric field; (iii) high resolution separation of model proteins achieved in 20 mm length column; (iv) multi-units with 48 micro-columns can be easily integrated to obtain high throughput; and (v) good linearity of pH gradient ( R =0.9989). More importantly, utility of the device was tested by using hemoglobins sample from human red blood cell. HbA 0 and HbA 1c with only Δp I 0.03 have been successfully separated by the developed method.
研究领域:
生物化学
·
分析化学
·
蛋白质组学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）