CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2021
·
IF 3.171
Xiangyu Dou,Haoyang Huang,Yongsheng Han
Nucleation widely exists in nature, from cloud formation to haze generation. The classical nucleation theory (CNT) was created to describe the nucleation process, but it fails to predict many experimental phenomena due to the short consideration of nanoscale phenomena and macroscale dynamics. Although the attachment and detachment of monomers are considered in the developed model of nucleation, the diffusion of chemicals in the bulk is not valued as supersaturation in the nucleation process so far. Here we employ simulation and experimental approaches to investigate how the diffusion of ions affects the nucleation of calcium carbonate. The diffusion of ions is regulated by the viscosity of solvents and the sonication imposed on the solution. It is found that the nucleation rates increased exponentially with the diffusion coefficient of ions, which is beyond the prediction of CNT. This abnormal finding might be ascribed to the involvement of cluster aggregation in the nucleation of calcium carbonate. This study highlights the significance of chemical diffusion in the nucleation process, which may help to revise the nucleation theory and develop solutions for the rational synthesis of materials, as well as for the control of air pollution.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Russian Journal of Physical Chemistry A
·
2024
·Vol. 97
·期 14
·3227-3237
·
IF 0.7
Zheng Yayuan
This paper investigates the kinetics of sodium sulfate crystallization in a stirred bed crystallizer through experimental analysis, focusing on the homogeneous and heterogeneous nucleation mechanisms of the compound. Key nucleation parameters, including tension (γ), critical nucleation radius ( r* ), critical nucleation free energy (Δ G* ), and critical nucleation molecule number ( i* ), are measured under various temperatures and supersaturation ratios, utilizing classical nucleation theory. The results demonstrate that as temperature and supersaturation ratio increase, induction time, critical nucleation free energy, critical nucleation radius, and critical molecule number decrease, while nucleation rate increases. The crystal shape remains relatively constant with changes in temperature and supersaturation ratio, but the average particle size increases with higher supersaturation and temperature. The observed changes in nucleation parameters are consistent with classical nucleation theory. In addition, population balance equations are employed to fit kinetic equations for crystal nucleation and growth rates in a stirred crystallization system. The results show that the growth rate increases with higher supersaturation and stirring rates, while the influence of parameters in the nucleation rate equation suggests that suspension density has the greatest effect, followed by supersaturation ratio and stirring rate.
研究领域:
化学工程
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材料科学
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物理化学
·
过程工程
·
晶体工程
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Soojin Kwon,Richard Lakerveld
Emulsion solution crystallization can achieve a narrow and predictable crystal size distribution (CSD) when the emulsion droplets are uniform. The crystallization kinetics of emulsion solution crystallization are generally different from those of conventional bulk crystallization. This work characterizes the impact of temperature profile on emulsion solution cooling crystallization. The temperature is controlled by a tubular heat exchanger, and a membrane is used to create an emulsion with controllable droplet size distribution. The crystallization performance is characterized by the dynamic development of the crystal number density and the CSD, which are compared with those of bulk cooling crystallization. The crystal number density is highly sensitive to the cooling profile, and the process behavior is consistent with a system dominated by primary nucleation. Regardless of the cooling profile, secondary nucleation is suppressed in the emulsion with confined crystallization inside the droplets, which results in a narrow CSD. In contrast, secondary nucleation is dominant in bulk crystallization, leading to a broader CSD with a higher crystal number density. The mean crystal length decreases as the batch time increases with emulsion crystallization, which is different from bulk crystallization. A more predictable and narrower CSD can be obtained from emulsion crystallization, but a higher supersaturation or longer batch time is needed in emulsion crystallization to achieve a similar yield when compared to that in conventional bulk cooling crystallization.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2023
·Vol. 29
·期 1
·141
·
IF 4.6
Yayuan Zheng
This paper explores the kinetics of the crystallization of potassium sulfate in a stirred bed crystallizer through experimental investigation. Employing classical nucleation theory, the homogeneous and heterogeneous nucleation mechanisms of potassium sulfate were investigated. The induction time and critical nucleation parameters, including the surface tension (γ), critical nucleation radius (r*), critical nucleation free energy (ΔG*), and critical nucleation molecule number (i*), were meticulously determined under varying temperatures and supersaturation ratios. The experimental findings revealed that as the temperature and supersaturation ratio increased, the induction time, critical nucleation free energy, critical nucleation radius, and critical molecule number decreased whereas the nucleation rate increased. The crystalline shape remains relatively unaltered with respect to temperature and supersaturation ratio, yet the particle size (D10, D50, D90) increases as the supersaturation and temperature increase. The variations in the measured nucleation parameters align well with the predictions of classical nucleation theory. Furthermore, the kinetic equations of crystal nucleation and the growth rate in a stirred crystallization system were fitted using population balance equations. The results demonstrate that the growth rate increases with increasing supersaturation and stirring rates. Additionally, the effects of the parameters in the nucleation rate equation suggested that the suspension density exerted the greatest influence, followed by the supersaturation ratio and stirring rate. This extensive research provides invaluable theoretical guidance for optimizing the crystallization process and designing industrial crystallizers.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Dongbo Wang,Ying Wang,Yuan Li,Ting Shi,Dandan Han,Junbo Gong
Impurity sugars produced in upstream process of functional sugars are significantly impacting the product quality. In this work, the effect of congeners ( d -maltose ( d -MAL), d -fructose ( d -FRU), d -glucose ( d -GLU)) on primary and secondary nucleation of d -tagatose ( d -TAG) crystals was investigated. The impurity sugars showed an inhibition on primary nucleation of d -TAG crystals, while a promotion on the secondary nucleation of d -TAG. Interestingly, the impact of impurity sugars on d -TAG crystal growth was similar to that on primary nucleation. The diffusion ability, hydrogen bonding forming ability, interaction energy of d -TAG crystal surfaces and impurity sugars were evaluated by molecular dynamics (MD) simulations to reveal the nucleation and growth behavior. Based on the above findings, we designed the d -TAG crystallization experiments, and obtained d -TAG crystals with uniform particle size distribution and regular morphology. This study helps to understand the influence of impurity sugars on crystallization, guiding the industrial manufacturing of functional sugars.
研究领域:
化学工程
·
材料科学
·
物理化学
✓ 已验证
DOI
PubMed
高影响因子
POLYMER TESTING
·
2021
·
IF 4.282
Bujin Liu,Jun Gu,Tuanhui Jiang,Rong Deng,Jingkui Yang,Xiangbu Zeng,Chun Zhang,Li He,Wei Gong
The morphology, size and surface roughness of the nucleating agent significantly affect the nucleation effect for foaming in the polymer. In this work, four nucleating agents with different morphologies, namely DE, MS, OMMT and β- CD as heterogeneous nucleation agents were selected for a polypropylene (PP) foaming injection molding process to explore nucleation mechanism. A theoretical assumption (cavity nucleation) in polymer foaming had been put forward about how to enhance the efficiency of bubble nucleation based on classical nucleation theory (CNT). Subsequently, the cavity nucleation was validated by chemical core-back injection foaming molding and in-situ visualization and elaborated by establishing a formula. Finally, designed petals shape particles as nucleating agents to further test this theory. The confirmation of this theory effectively improved the nucleation efficiency and foaming quality, which has important guiding significance to the development of lightweight products.
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
CRYSTENGCOMM
·
2017
·Vol. 19
·期 47
·7207-7212
·
IF 3.474
Zhiyan Chen,Yabo Zhu,Jia Lei,Wanying Liu,Yunke Xu,Peizhong Feng
In the preparation of black phosphorene (BP) by means of low-pressure mineralization, the complex temperature program makes the synthesis mechanism complicated and confusing. Herein, orthorhombic BP crystals were successfully synthesized by low-pressure mineralization and the phase transitions at every stage were revealed systematically and were accurately confirmed via a series of interference experiments and supported by structure characterization. Additionally, the nucleation agents and nucleation sites were systematically investigated. Based on this, we found that the synthesis of BP is a process of stage-by-stage phase-induction. At first, red phosphorus (RP) is transformed to Hittorf's phosphorus (HP) without the assistance of mineralizers. Subsequently, HP is transformed into BP at the cooling stage. Moreover, Sn24P19.3I8 should work as the sole nucleation agent, and leads to BP crystal nucleation and growth to form large crystals in the subsequent heat preservation stage. Also, the nucleation site lies in the product region opposite the source region. In addition, the radial morphology of the BP crystal bunches under an RP/SnI4/Sn (granule) system was revealed firstly, and taking the straps out from the BP bunches is convenient for exfoliating.
研究领域:
材料科学
·
凝聚态物理
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纳米技术
·
晶体生长
·
功能材料
✓ 已验证
DOI
高影响因子
Nature Communications
·
2021
·Vol. 12
·期 1
·1-10
·
IF 14.919
Ma Lin,Yan Zhengguang,Zhou Xiaoyuan,Pi Yiqun,Du Yiping,Huang Jie,Wang Kaiwen,Wu Ke,Zhuang Chunqiang,Han Xiaodong
Recently, there are significant progresses in the growth of organic-inorganic lead halide perovskite single crystals, however, due to their susceptible nucleation and growth mechanisms and solvent requirements, the efficient and generalized growth for these single crystals is still challenging. Here we report the work towards this target with a polymer-controlled nucleation process for the highly efficient growth of large-size high-quality simple ternary, mixed-cations and mixed-halide perovskite single crystals. Among them, the carrier lifetime of FAPbBr 3 single crystals is largely improved to 10199 ns. Mixed MA/FAPbBr 3 single crystals are synthesized. The crucial point in this process is suggested to be an appropriate coordinative interaction between polymer oxygen groups and Pb 2+ , greatly decreasing the nuclei concentrations by as much as 4 orders of magnitudes. This polymer-controlled route would help optimizing the solution-based OIHPs crystal growth and promoting applications of perovskite single crystals.
研究领域:
材料科学
·
化学
·
物理学
✓ 已验证
DOI
高影响因子
Materials Research Express
·
2020
·Vol. 7
·期 1
·015522
·
IF 1.929
Tingyu Song,Lifeng Gao,Qi Wei,Limin Yu,Shiwei Wang,Mingyao Zhang,Lisha Zhao,Yanhua Cai
Organic-inorganic hybrid halide perovskites have attracted great interest for scientists and entrepreneurs due to their intrinsic properties and considerable business prospects in recent years. Perovskite single crystal can determine its properties well because of no grain boundaries for itself, so it is necessary to study the nucleation and growth process of perovskite crystals. In this work, CH3NH3PbI3−xClx single crystals with about 10 mm sized are prepared. It's found that chlorine can restrict the nucleation and slow crystallization during the perovskite grown process. Moreover, the number of perovskite crystals can be controlled by tuning the content of chlorine in the precursor solutions, because chlorine can restrict the perovskite crystal nucleation as an inhibitor.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Chenlu Xue,Haipeng Jiang,Chenchen Zhu,Wei Gao
AlH 3 is a promising hydrogen storage material, but poses an explosion risk when suspended in air. Herein, a low-cost and environmentally friendly composite explosion suppressant is prepared using ultrasound coupled cooling crystallization and applied to suppress AlH 3 explosions. Ultrasound-induced cavitation inhibits crystal agglomeration, resulting in fine KH 2 PO 4 crystals growing on the SiO 2 surface by heterogeneous nucleation, which significantly improves the suppression effect. The decomposition products of KH 2 PO 4 react with the flame radicals in the system to generate stable products, interrupting the chain reaction of flame radicals effectively. Furthermore, the complex mesoporous structure of SiO 2 absorbs flame radicals and increases the collision probability between the radicals and the pore walls, thus suppressing flame propagation. Our research provides an important theoretical support for the safe application of light metal hydrogen storage materials.
研究领域:
材料科学
·
能源存储
·
安全工程
✓ 已验证
产品关联
DOI
高影响因子
Coatings
·
2017
·Vol. 7
·期 6
·78
·
IF 2.175
Shengzhong Jin,Shichao Zhao,Jiaxin Weng,Yanfei Lv
Molybdenum disulphide (MoS2) monolayer is a two-dimensional semiconductor material with potential applications in nano electronic devices. However, it is still a challenge to reproducibly synthesize single layer MoS2in high quality. Herein, we report the growth of monolayer of MoS2on the SiO2/Si substrate with manganese heterogeneous nucleation. It was shown that the Mn promotes the growth of monolayer MoS2via heterogeneous nucleation. The growth temperature range expanded two-fold, the nucleation density increased as well. The monolayer prepared in the presence of Mn exhibits a unique red emission peak at 732 nm at room temperature compared to the sample in the absence of Mn.Keywords:molybdenum disulphide;heterogeneous nucleation;growth;photoluminescence
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2022
·Vol. 12
·期 2
·202
·
IF 2.67
Yanfei Wang,Xiaoyu Chuai,Yifei Li,Jia Guo,Jing Yang,Zhixue Liu,Shijie Xu
In this contribution, we experimentally determined the metastable zone width (MSZW) of adipic acid (AA) in different polar solvents to reveal the nucleation behavior. We performed analyses for different cooling rates, saturation temperatures and polar solvents. The findings showed that the MSZW increased as the cooling rate increased, or saturation temperature or polarity decreased. Here, we suggest that the hydrogen bond donor capacity decreases as the polarity of the solvent decreases, which weakens the solute and solvent interaction and makes the desolvation process more difficult during nucleation. Furthermore, we found that the MSZW is mainly determined by the cooling rate, when the cooling rate is large enough. On account of the classical nucleation theory, it was found that the sizes of the critical nucleus and Gibbs nucleation energy do not increase monotonously with increasing driving force. Moreover, this study confirms that solid–liquid interface tension is associated with crystallization driving force.Keywords:adipic acid;nucleation;MSZW;critical nucleation parameter
研究领域:
化学工程
·
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）