JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2014
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IF 3.552
Lingling Ge,Shuhui Lu,Rong Guo
Janus emulsions of a polymerizable monomer tripropyleneglycol diacrylate (TP) combined with silicone oil (SO) as inner oil phases and Tween 80 aqueous solution as continuous phase are prepared in a one-step high energy mixing process. The dependence of droplet topology on the concentration of surfactant, TP/SO ratio, and the stirring speed during emulsification is investigated. The result shows that the volume ratio of two oils within an individual droplet changes correspondingly to the total composition of emulsion. Increasing the speed of stirring results in a significant reduction in the droplet size, i.e. a five times increase in the stirring speed produces a droplet size reduction from hundreds to a few microns. What is more important, the topology of Janus drops remains similar for the different preparations. These fundamental investigations illustrate the potential for future Janus particle synthesis in batch scale with a controllable particle topology.
研究领域:
化学工程
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材料科学
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产品关联
DOI
PubMed
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2022
·
IF 4.264
Zhangcheng Gao,Jianqing Wang,Lianfang Feng,Xueping Gu,Jintang Duan,Cailiang Zhang
Under the conditions specified in this work, the polycondensation reaction to prepare rigid rodlike poly(p-phenylene-cis-benzobisoxazole) (PBO) is diffusion-controlled. This work aims to study the flow-driven polycondensation reaction of PBO. The effect of mixing efficiency through changing the stirring speed on the polycondensation reaction of PBO was first investigated in a paddle impeller reactor (PIR). In the initial stage of polymerization, the increase of stirring speed is obviously conducive to accelerating the polycondensation reaction. However, the promoting effect of stirring speed on the polycondensation reaction is greatly reduced in the middle and late stages of polymerization. The effect of the flow pattern with different proportions of shear flow, elongational flow and rotational flow on the polycondensation reaction of PBO was further investigated by comparing three reactors including Couette-Taylor reactor (CTR) with a complete shear flow, PIR with strong shear and elongational flows, and double helical ribbon reactor (DHR) with strong shear and rotational flows. Result shows that the improvement of proportions of rotational flow and elongational flow is beneficial to accelerate the polycondensation reaction of PBO in the middle and late stages of polymerization, especially for the rotational flow.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
Journal of the Mechanical Behavior of Biomedical Materials
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2025
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IF 3.5
Yaming Zhang,Xinyi Bai,Ding Li,Xi Liu,Xigeng Lyu,Fu Wang
Lithium disilicate (LD) glass-ceramics were fabricated through conventional sol-gel and pressureless sintering methods, with the influence of stirring speeds (200, 400, 600 and 1000 rpm) on their microstructural evolution, phase formation, and mechanical properties being systematically investigated. The variation in agitation speed significantly affected the agglomerated sizes and morphological characteristics of the gel-derived LD powers, which in true induced noticeable differences in phase compositions and crystallinities of both the precursor powers and the final glass-ceramics. These morphological variations directly correlated with the archived relative densities of the sintered LD glass-ceramics, and the mechanical property variations were also linked with the differing aspect ratios of the precipitated LD crystals within the microstructures. Optimal performance was obtained at the stirring speed of 400 rpm, yielding glass-ceramics with exceptional properties: highest relative density (94.01 ± 0.16 %), flexural strength (182.72 ± 1.5 MPa), hardness (3.84 ± 0.20 GPa), and fracture toughness (3.07 ± 0.17 MPa·m 1/2 ). These finding demonstrated that mechanical stirring parameters profoundly influenced the characteristics of gel-derived LD powders and resultant glass-ceramics, suggesting potential applicability of this process control strategy to other gel-derived lithium silicate materials, including Li 2 SiO 3 and Li 4 SiO 4 .
研究领域:
材料科学
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无机非金属材料
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生物陶瓷
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牙科材料
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固态化学
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粉末冶金
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产品关联
DOI
PubMed
高影响因子
International Journal of Coal Preparation and Utilization
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2022
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IF 2.791
Qiming Zhuo,Wenli Liu,Xiaomiao Jiao,Hongxiang Xu,Xiaopeng Sun
A dynamic floc measurement system was developed to analyze flocs during sedimentation and automatically extract floc characteristics without damaging them. An optimized algorithm was proposed to remove fuzzy flocs, and visual inspection verified that this algorithm achieved satisfactory separation performance between well-defined and fuzzy flocs. This program was used to study the development of coal flocs and showed that the flocs grew rapidly at the beginning of flocculation. The floc size at equilibrium at low stirring velocities was larger than those at high stirring velocities. A high stirring velocity can cause irreversible damage to the flocs, and those flocs cannot be restored to their original size by decreasing the stirring velocity. In addition, the fractal dimension decreased with increasing time, indicating that there is an optimal stirring velocity which can be selected to enhance the size and structure of flocs. This research provided an effective way to study the characteristics of flocs, and the change process of the flocs under different stirring velocities was investigated in detail to understand the growth, breakage, and regrowth process.
研究领域:
化学工程
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环境科学
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材料科学
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产品关联
DOI
高影响因子
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
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2018
·Vol. 645
·期 2
·73-78
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IF 1.179
Xufei Li,Bo Tang,Weiqiu Huang,Haogang Yu
Zeolite imidazolate frameworks (ZIFs) represent a class of metal-organic frameworks (MOFs) for various potential applications due to their outstanding properties. However, to date, the creation of nanoframes with tunable structure faces a challenge. Herein, we develop a facile and efficient physical method that allows the preparation of ZIF-90 with controllable surface area. In this study, the effect of various stirring time and speed in the acceleration of the precursor dissolution are revealed. The study shows that a moderate stirring speed (640 r · min –1 ) and reaction time (6 h) are the optimal conditions to synthesize ZIF-90 with a high adsorption capacity. More importantly, the maximum adsorption amount of n -hexane is up to 211 mg · g –1 by using this as-prepared sample, which increases by 60 % in comparison with that of the minimum from other sample (133 mg · g –1 ).
研究领域:
材料科学
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化学工程
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环境科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
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IF 3.573
Kai Ge,Yuanhui Ji,Shuai Tang
The influence of various factors (e.g., temperature, stirring speed, pH, and alginic acid concentration) on the crystallization kinetics of magnesium ammonium phosphate hexahydrate (MAP) was evaluated. The chemical potential gradient models were used to analyze the MAP crystallization mechanism and predict MAP crystallization kinetics. It was found that the temperature and stirring speed mainly influenced the kinetic rate constant, while alginic acid additives mainly influenced the thermodynamic driving force of MAP. The pH mainly influenced both the rate constant and the thermodynamic driving force, which is the key influencing factor of the crystallization rate and performance of MAP. The theoretical modeling indicated that the MAP crystallization mechanism was dominated by the adhesive-type growth mechanism. Furthermore, the crystallization kinetics of MAP was successfully predicted as a function of alginic acid concentration with high accuracy. This work is expected to provide important information for selecting appropriate operating parameters to control the performance of MAP in practical applications.
研究领域:
化学工程
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材料科学
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物理化学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Shuai Tang,Yuanhui Ji,Kai Ge
In this work, four influencing factors including temperature, stirring speed, pH value, and polymer concentration were chosen to investigate crystallization kinetics of calcium sulfate dihydrate (CSD). At the same time, the chemical-potential-gradient models combined with the extended Debye–Hückel model were used to explore the growth mechanism of CSD and predict the crystal growth kinetics under different external conditions. The results indicated that temperature was the key influencing factor because of the sensitivity of the rate constant kt and driving force Δμ to temperature changes. Moreover, the pH nearly has little effect on them, while the stirring speed and polymer concentration primarily affected kt and Δμ, respectively. On the other hand, the theoretical models indicated that the crystallization mechanism of CSD belonged to the adhesive-type growth mechanism. Moreover, the CSD crystal growth kinetics was well predicted at different temperatures, pH values, and polymer concentrations. Unfortunately, the crystallization kinetics of CSD under different stirring speeds cannot be accurately predicted. The detailed information, such as the key influencing factor and the crystallization mechanism, could provide a reference for the removal of scale in industrial production.
研究领域:
材料科学
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化工工程
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物理化学
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产品关联
DOI
高影响因子
Journal of Macromolecular Science Part B-Physics
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2021
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IF 1.504
Chao Zhang,Zhihua Zhou,Wenjuan Liu,Tianlong Huang,Yanmin Zhao,Ping Chen,Ziwei Zhou,Dan Wang,Meiling Yi,Jianjun Fang
Porous microspheres have interconnecting external and internal pore structure resulting in enormous specific surface area and have drawn attention for drug delivery. In this work, poly(l-lactide-co-glycolide-co-ε-caprolactone) (PLLGC) porous microspheres were prepared by a combined solvent evaporation and particle leaching method using gelatin as a porogen. The effects of preparation parameters on the morphologies of the porous microspheres were studied. The resultant microspheres showed porous surfaces and a three-dimensional internal network structure with interconnecting pores. The porous microsphere size decreased with increasing stirring speed and decreasing PLLGC concentration. There were fewer micropores on the surfaces of the microspheres with increasing temperature. The number of the pores and pore size on the surface of the microspheres increased with increasing gelatin content. By appropriate control of these factors (stirring speed 300 rpm, PLLGC solution concentration 1.0 wt%, temperature 0 °C, and gelatin concentration 7.5 wt%), a suitable porous microsphere, with a mean diameter of 200 μm, was prepared as a potential drug delivery agent.
研究领域:
材料科学
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高分子科学
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药剂技术
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生物医学工程
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药物递送系统
✓ 已验证
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2023
·
IF 3.8
Qiao Chen,Jingyun Weng,Gabriele Sadowski,Yuanhui Ji
In this work, the influence of temperature, stirring speed, and polymeric excipients on crystal growth kinetics of active pharmaceutical ingredients (APIs) mesalazine and allopurinol was systematically investigated through experimental measurement and chemical potential gradient model. The results indicated that the two-step chemical potential gradient model showed good performance in modeling API crystal growth kinetics within the average relative deviations (ARDs) of 5%. Excipients (poly(ethylene glycol) (PEG), hydroxypropyl methyl cellulose (HPMC), and poly(vinyl pyrrolidone) (PVP)) played a crucial role in inhibiting the API crystal growth in all of the investigated systems. On one hand, excipients improved the API solubility, and on the other hand, the crystal growth rate of APIs was reduced remarkably by excipients. By comparing the diffusion rate constant (kd) and the surface reaction rate constant (ks) within the two-step chemical potential gradient model, it was found that the controlling step of mesalazine and allopurinol crystal growth was the surface reaction. Because of the presence of excipients, the diffusion rate constant was markedly decreased and the surface reaction order increased. Excipients hinder the surface reaction and decrease the crystal growth rate. Meanwhile, the crystal growth kinetics of mesalazine and allopurinol were predicted successfully with the ARDs of 2.5 and 6.5% under a certain temperature and stirring speed by the two-step chemical potential gradient model. This work provided a mechanistic understanding of how polymers inhibit API crystal growth.
研究领域:
药学
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化学工程
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材料科学
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 29
·期 17
·25810-25823
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IF 4.223
Shang Zhijie,Xu Pan,Yue Haoyu,Feng Dongyue,Zhu Taohua,Li Xinxue
The increasing diesel pollution accidents pose a serious threat to the ecological environment and human health. Remediation of diesel-contaminated soil (DCS) has attracted widespread attention during the past few decades. This work proposed an approach for the remediation of DCS by alkoxyethanol aqueous two-phase extraction (ATPE), which was an application of this small molecule aqueous two-phase system (ATPS). In addition, the influence of temperature, stirring speed, stirring time, and solid–liquid ratio on the removal of diesel was explored respectively. The removal efficiency of diesel could reach more than 97.18% in 18 min. Meanwhile, ATPS had high reusability, and the removal efficiency remained above 85.17% in the reuse process. Alkoxyethanol ATPE could effectively remove diesel hydrocarbons with different carbon chain lengths and the remediation process hardly caused residual organic solvents on the soil surface according to the analysis of gas chromatography-mass spectrometry (GC–MS) and Fourier transforms infrared (FT-IR), which could be regarded as the distinct advantage compared to the traditional surfactant washing method and organic solvent extraction method. The study of soil physicochemical properties and wheat germination proved that the soil structure and properties changed little after ATPE remediation. And finally, the mechanism of alkoxyethanol ATPE was intensively discussed according to the remediation characteristic. This work provided an efficient method for the remediation of DCS and widened the application fields of alkoxyethanol ATPS as well. Graphical abstract
研究领域:
环境科学
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土壤学
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化学工程
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污染控制
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产品关联
DOI
PubMed
高影响因子
COMPUTERS IN BIOLOGY AND MEDICINE
·
2023
·
IF 7.7
Jinyi Qian,Yuzhou Wang,Xiner Liu,Zijian Hu,Nan Xu,Yuetong Wang,Tianqiong Shi,Chao Ye
Acetoin was widely used in food, medicine, and other industries, because of its unique fragrance. Bacillus amyloliquefaciens was recognized as a safe strain and a promising acetoin producer in fermentation. However, due to the complexity of its metabolic network, it had not been fully utilized. Therefore, a genome-scale metabolic network model ( i JYQ746) of B. amyloliquefaciens was constructed in this study, containing 746 genes, 1736 reactions, and 1611 metabolites. The results showed that Mg 2+ , Mn 2+ , and Fe 2+ have inhibitory effects on acetoin. When the stirring speed was 400 rpm, the maximum titer was 49.8 g L −1 . Minimization of metabolic adjustments (MOMA) was used to identify potential metabolic modification targets 2-oxoglutarate aminotransferase ( serC , EC 2.6.1.52) and glucose-6-phosphate isomerase ( pgi , EC 5.3.1.9). These targets could effectively accumulate acetoin by increasing pyruvate content, and the acetoin synthesis rate was increased by 610% and 10%, respectively. This provides a theoretical basis for metabolic engineering to reasonably transform B. amyloliquefaciens and produce acetoin.
研究领域:
生物技术
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代谢工程
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微生物学
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产品关联
DOI
PubMed
高影响因子
Frontiers of Chemical Science and Engineering
·
2023
·Vol. 17
·期 10
·1503-1515
·
IF 4.5
Chen Qiao,Zhang Mingdong,Ji Yuanhui
In this work, the influence of the initial chemical potential gradient, stirring speed, and polymer type on sulfamethoxazole (SMX) crystal growth kinetics was systematically investigated through density functional theory (DFT) calculations, experimental measurements and the two-step chemical potential gradient model. To investigate the influence of different conditions on the thermodynamic driving force of SMX crystal growth, SMX solubilities in different polymer solutions were studied. Four model polymers effectively improved SMX solubility. It was further found that polyvinylpyrrolidone (PVP) and hydroxypropyl methyl cellulose (HPMC) played a crucial role in inhibiting SMX crystal growth. However, polyethylene glycol (PEG) promoted SMX crystal growth. The effect of the polymer on the crystal growth mechanisms of SMX was further analyzed by the two-step chemical potential gradient model. In the system containing PEG 6000, crystal growth is dominated by the surface reaction. However, in the system containing PEG 20000, crystal growth is dominated by both the surface reaction and diffusion. In addition, DFT calculations results showed that HPMC and PVP could form strong and stable binding energies with SMX, indicating that PVP and HPMC had the potential ability to inhibit SMX crystal growth.
研究领域:
药学
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材料科学
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化学工程
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计算化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）