Microsystems & Nanoengineering
·
2023
·Vol. 9
·期 1
·1-13
·
IF 7.9
Huang Biao,Ge Xinjin,Rubinstein Boris Y.,Chen Xianchun,Wang Lu,Xie Huiying,Leshansky Alexander M.,Li Zhenzhen
Micron- and submicron-sized droplets have extensive applications in biomedical diagnosis and drug delivery. Moreover, accurate high-throughput analysis requires a uniform droplet size distribution and high production rates. Although the previously reported microfluidic coflow step-emulsification method can be used to generate highly monodispersed droplets, the droplet diameter ( d ) is constrained by the microchannel height ( b ), \(d\gtrsim 3b\) , while the production rate is limited by the maximum capillary number of the step-emulsification regime, impeding emulsification of highly viscous liquids. In this paper, we report a novel, gas-assisted coflow step-emulsification method, where air serves as the innermost phase of a precursor hollow-core air/oil/water emulsion. Air gradually diffuses out, producing oil droplets. The size of the hollow-core droplets and the ultrathin oil layer thickness both follow the scaling laws of triphasic step-emulsification. The minimal droplet size attains \(d\approx 1.7b\) , inaccessible in standard all-liquid biphasic step-emulsification. The production rate per single channel is an order-of-magnitude higher than that in the standard all-liquid biphasic step-emulsification and is also superior to alternative emulsification methods. Due to low gas viscosity, the method can also be used to generate micron- and submicron-sized droplets of high-viscosity fluids, while the inert nature of the auxiliary gas offers high versatility.
研究领域:
生物医学工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2020
·
IF 3.871
Ya-Ni Ji,Wen-Jie Geng,Chun-Yang Ma,Jing Tan,Wen-Sheng Deng,Bin Liu,Yue-Feng Su
A simple and effective method was conducted for preparing microdispersed droplets with decreased size and increased uniformity, in which phase inversion in high-phase-ratio liquid/liquid system was combined with addition of microbubbles. Five typical flow patterns were observed, including W/O, O/W/O, transition regime, O/W and G/W/O regimes. Flow regime transition was observed, according to which physical properties of systems and operating conditions for preparing single-oil-droplet-in-water emulsion were determined in different liquid/liquid and gas/liquid/liquid modes. Effects of liquid viscosities as well as interfacial tension on droplet size ( D O ) and its standard deviation (SD) were studied systematically and the most effective gas/liquid/liquid mode was recommended. Mathematical models were established for correlating D O in five different modes, which show relatively good agreement with experimental results. D O decreases by 42% via introducing phase inversion and further reduces to 25% by addition of microbubbles, both under the same operating conditions.
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
Reaction Chemistry & Engineering
·
2022
·Vol. 7
·期 11
·2322-2333
·
IF 5.2
Jing Song,Chencan Du,Junjie Wang,Yongjin Cui,Yujun Wang,Jian Deng,Guangsheng Luo
Microreaction technology provides a powerful tool for reactions under extreme conditions, but the micro-dispersion performance of those processes under real reaction conditions is hard to visualize. Therefore, we constructed a novel observation platform by placing the downstream observation window vertically. We successfully achieved the accurate measurement of droplets ranging in size from microns to millimeters for real reaction systems in a T-junction microdevice, and proved that the droplet coalescence can be avoided at the outlet of the microreactor. The actual micro-dispersion state of different types of systems can be exactly reflected in the observation window. We further investigated the effect of shearing routes on the droplet size in toluene nitration by using this platform and provided design guidance on the choice of shearing routes for nitration. The scaling laws under different shearing routes have been established based on the obtained micro-dispersion data in this work. This work has promoted the connection of fundamental research studies with real applications of microreaction technology, which is critical for the future development of microreaction technology.
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
Applied Sciences-Basel
·
2021
·Vol. 11
·期 16
·7258
·
IF 2.679
Qi Liu,Shengde Chen,Guobin Wang,Yubin Lan
Background: Unmanned Aerial Vehicles (UAVs) applied to agricultural plant protection is widely used, and the field of operation is expanding due to their high efficiency and pesticide application reduction. However, the work on pesticide drift lags behind the development of the UAV spraying device. Methods: We compared the spray drift potential at four liquid pressures of 2, 3, 4, and 5 bar ejected from the hydraulic nozzles mounted on a UAV test platform exposed to different wind speeds of 2, 4, and 6 m/s produced by a wind tunnel. The combination of the wind tunnel and the UAV test platform was used to obtain strict test conditions. The droplet size distribution under spray drift pressures was measured by a laser diffraction instrument. Results: Increasing the pressure leads to smaller droplet volume diameters and produced fine droplets of less than 100 µm. The deposition in the drift area was elevated at most of the sampling locations by setting higher pressure and faster wind speed. The deposition ratios were all higher than the flow ratios under three wind speeds after the adjustment of pressures. For most samples within a short drift distance (2–8 m), the drift with the rotor motor off was more than an order of magnitude higher than that with the rotor motor on at a pressure of 3 bar. Conclusions: In this study, the wind speed and liquid pressure all had a significant effect on the UAV spray drift, and the rotor wind significantly inhibited a large number of droplets from drifting further.Keywords:unmanned aerial vehicle;liquid pressure;drift deposition;wind speed;rotor wind field;droplet size
研究领域:
农业工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2015
·
IF 4.321
Lu Qi,Xianghai Meng,Rui Zhang,Haiyan Liu,Chunming Xu,Zhichang Liu,Peter A.A. Klusener
Droplet size distribution (DSD) and mean droplet size of chloroaluminate ionic liquid (IL)–heptane dispersion in a stirred vessel were investigated as a model system for the composite ionic liquid/hydrocarbon system applied in the commercial isobutane alkylation process. Focused beam reflectance measurement was used to identify the phase inversion, and particle video microscope (PVM) was employed to measure the DSD of IL-continuous dispersions. The effects of agitation speed and dispersed phase holdup on the DSD and mean droplet size were investigated. Phase inversion was found at a heptane hold-up of just above 0.5. The observed DSDs could be described well by logarithmic normal distributions in spite of variable operating conditions. The DSDs appeared to be more or less independent of the dispersed phase holdup ( ϕ heptane ⩾ 0.3) at the same agitation speed. A semi-empirical correlation based on Shinnar theory was proposed to predict the droplet mean size in the impeller region for the IL-continuous dispersion, and the predicted value agreed well with the experimental data. This work will be a good basis to predict the dispersion behavior under process conditions.
研究领域:
化学工程
·
流体力学
·
多相系统
·
过程工程
·
胶体与界面科学
✓ 已验证
DOI
高影响因子
LIQUID CRYSTALS
·
2020
·
IF 2.908
Gang Hu,Hongxiang Chen,Zhiqiang Liu,Song Zhang,Yu Zhou,Bailin Zhu,Huazhi Gu
To improve the electro-optical properties of polymer-dispersed liquid crystal (PDLC) film, the size and number of liquid crystal droplets were regulated by changing component, curing method, curing temperature and time, and so on, but the regulation reported in the literatures was constrained within the curing process. In this work, the size of liquid crystal droplets is regulated by quenching around the glass transition temperature (Tg) at which the mobility of polymer chains changes dramatically. At the same time, the degree of supersaturation of liquid crystal molecules changes due to the decrease of temperature, thereby regulating the number of nucleation of liquid crystal droplets. Through the study of the above process, the effects of the size and number of liquid crystal droplets and the content of liquid crystal dissolved in the polymer network on the electro-optical properties of PDLC film are discussed. The research provides a new method to regulate the structure and properties of PDLC film aiming at the cured PDLC film, effectively overcoming the disadvantage of the regulation aiming at the curing process.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Xinyi Li,Shuchun Zhao,Junheng Guo,Wei Li,Jinli Zhang
For industrial emulsification processes, it remains a challenge to obtain desirable droplet size distribution (DSD) as well as a smaller span via facile and efficient routes. In this work, a novel blind-side rotor is designed to assemble with the stator of a laboratory-scale inline high-shear mixer equipped with an annular cylinder inside the mixing chamber (bRS HSM). The effects of operating parameters, structural parameters on the average droplet size, DSD, and span are experimentally investigated and compared with those of commercially used toothed-type rotor-stator assembly. In addition, computational fluid dynamics calculations are performed to investigate the influences on the flow field of the fluid within the HSM. The results show that the structure of the bRS HSM not only generates an optimal span but also reduces the energy consumption of the mixer, which is more advantageous for production of emulsions with narrower DSD. In the bRS HSM, Sauter mean diameter (d32) and span decrease with increasing rotor speed but decreasing flow rate of the continuous phase, while span decreases and then increases with increasing volume fraction of the dispersed phase. Meanwhile, the effect of structural parameters on span is nonmonotonic. Furthermore, the artificial neural network (ANN) model is used to perform the correlation of d32 and span, providing an estimation method to optimize the operating and structural parameters of the inline HSM in the emulsification process.
研究领域:
化学工程
·
过程工程
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2023
·
IF 10.7
Yue Dong,Zihao Wei,Changhu Xue
The effect of interaction between ovotransferrin fibrils (OVTFs) and citrus pectin (CP) on the properties of oleogel-based Pickering emulsions was innovatively explored. Firstly, the interaction between OVTFs and CP was investigated by constructing OVTF–CP complexes. OVTF–CP complexes with better stability were obtained when OVTFs to CP mass ratio of 3:1 at pH 5.0, which exhibited pearl chain-like structures by electrostatic attractions. Subsequently, to discuss the effect of interaction between OVTFs and CP on the properties of oleogel-based Pickering emulsions, oleogel-based OVTF-stabilized Pickering emulsion (OE) and oleogel-based OVTF–CP complex-stabilized Pickering emulsion (OCPE) were developed. The interaction between OVTFs and CP endowed OCPE with better stability, smaller droplet size, more prominent gel-like structure, higher viscosity and superior texture properties compared with OE. To construct an efficient delivery system for nutraceuticals, OE and OCPE were used to load curcumin . Compared with curcumin-loaded OE, curcumin-loaded OCPE had excellent protection for curcumin, higher rate of lipolysis and bioaccessibility of curcumin. Our work demonstrates that the interaction between OVTFs and CP can regulate the properties of oleogel-based Pickering emulsions, which will provide new insights into the formation and application of protein fibril–polysaccharide complexes. This may contribute to the precise development of Pickering emulsions with protein fibril–polysaccharide structures and ideal properties.
研究领域:
食品科学
·
胶体科学
·
营养保健品
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wenya Liao,Zhiqiang Wu,Li Liu,Qianqian Lu,Pengfei Wang,Xing Huang,Zhongbin Xu
Microdroplets play a crucial role in various applications based on microfluidics, including biomedicine, materials synthesis, and analytical chemistry. However, there is still an urgent need for a microdroplet preparation method that is simple in design, precise in droplet size control and meanwhile independent of the properties of the fluid. Here, we present a piezoelectric-synchronized step emulsification method. The drop formation process can be synchronized by the introduced periodic vibration via the piezoelectric element, which occurs in a specific frequency range determined by a dimensionless parameter. The competing between the step emulsification regime and the piezoelectric-triggered local flow rate fluctuation leads to various microscopic flow behavior. A novel instantaneous jetting regime is found to be responsible for the extended achievable drop size range. By combining the piezoelectric step emulsification and the XY stage control, we achieve facile production of microdroplet and hydrogel microsphere library in well plates, which is promising to be integrated as a low-cost drop-generating technique into bioassay instruments.
研究领域:
微流控
·
生物医学工程
·
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2023
·
IF 6
Di An,Liang Li
Enzymatic hydrolysis is an effective method to improve the physicochemical properties of soy protein isolate (SPI) nanofibrils and expand their application in stabilizing Pickering emulsion. In this work, the effects of enzymatic hydrolysis on the SPI fibrillation and the stabilization mechanisms of SPI hydrolysate nanofibrils for Pickering emulsion were investigated. According to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) images and Thioflavin T (ThT) fluorescence data, higher degree of hydrolysis (DH) contributed to releasing more small molecular weight peptides (mainly from α, α′, and β subunits) to improve apparent rate constant and surface hydrophobicity during fibrillation. When DH increased to 8%, SPI hydrolysate could form long and flexible nanofibrils and possessed the highest content of β-sheet (21.40%), when heated for 12 h. Enzymatic hydrolysis played various positive impacts on the interfacial properties of nanofibrils, including faster interfacial adsorption and near-neutral wettability (92.87°). SPI hydrolysate nanofibrils could impart enhanced gel-like structure and exceptional thermal stability to Pickering emulsions, resulting in a decrease in droplet size from 52.06 μm to 32.74 μm. This work will enhance the exploration of the formation mechanism of nanofibrils and broaden their application in the functional emulsion.
研究领域:
食品科学
·
胶体科学
·
材料科学
·
生物技术
✓ 已验证
DOI
高影响因子
Frontiers in Nutrition
·
2022
·
IF 6.59
Yang Lili,Zi Ye,Shi Cuiping,Chen Jiahui,Xu Jiamin,Wang Xichang,Zhong Jian
The exploration of deodorization is important for the application of gelatin in food industry. In this work, the effect of β-cyclodextrin (β-CD) deodorization on the volatile chemicals and functional properties of three types of gelatins (commercial porcine skin gelatin, cold water fish skin gelatin, and Chinese longsnout catfish skin gelatin) were studied. The results suggested the odors of commercial gelatins were significantly less than home-extracted gelatins. The β-CD deodorization efficiency was dependent on both β-CD concentration and volatile chemical. (E)-2-Octenal (C8H14O), 1-octen-3-ol (C8H16O), 2-pentyl-furan (C9H14O), and hentriacontane (C17H36) could be deodorized at low β-CD concentration (even at 2 mg/mL). The best β-CD deodorization concentration for 66.7 mg/mL of Chinese longsnout catfish skin gelatin was 30 mg/mL. β-CD addition could not change the gel forming ability and emulsion activity of gelatins, whereas it had different and concentration-dependent effects on the emulsion stability of gelatins. β-CD addition had no obvious effects on the droplet sizes, droplet coalescence and liquid-gel transition behaviors, but had different effects on the creaming of the emulsions stabilized by three types of gelatins. The encapsulation of β-carotene did not significantly change the droplet trimodal size distribution and liquid-gel transition of fish oil-loaded emulsions. However, β-carotene might delay the droplet coalescence. The creaming stability of β-carotene/fish oil-loaded gelatin/β-CD-stabilized emulsions was dependent on the gelatins, β-CD, and β-carotene. Finally, the β-carotene retention in the emulsions was dependent not on β-CD addition but on the nature of the gelatins. These results provided useful information to understand the molecular deodorization behaviors and explore the deodorization of emulsifiers for food emulsions.
研究领域:
食品科学
·
化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2022
·
IF 10.723
Xinyu Zhao,Shujuan Yang,Furui He,Haifang Liu,Keyang Mai,Junhao Huang,Gaobo Yu,Yuhong Feng,Jiacheng Li
Functional Pickering emulsions that depend on the interparticle interactions hold promise for building template materials. A novel coumarin-grafting alginate-based amphiphilic telechelic macromolecules (ATMs) undergoing photo-dimerization enhanced particle-particle interactions and changed the self-assembly behavior in solutions. The influence of self-organization of polymeric particles on the droplet size , microtopography, interfacial adsorption and viscoelasticity of Pickering emulsions were further determined by multi-scale methodology. Results showed that stronger attractive interparticle interactions of ATMs (post-UV) endowed Pickering emulsion with small droplet size (16.8 μm), low interfacial tension (9.31 mN/m), thick interfacial film, high interfacial viscoelasticity and adsorption mass, and well stability. The high yield stress, outstanding extrudability (n 1 < 1), high structure maintainability, and well shape retention ability, makes them ideal inks for direct 3D printing without any additions. The ATMs provides an increased capacity to produce stable Pickering emulsions with tailoring their interfacial performances and, providing a platform for fabricating and developing alginate-based Pickering emulsion-templated materials.
研究领域:
材料科学
·
化学工程
·
高分子化学
·
3D打印技术
✓ 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）