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Hydrogen-bond mediated and concentrate-dependent NaHCO_(3) crystal morphology in NaHCO3–Na2CO3 aqueous solution: Experiments and computer simulations

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Chinese Journal of Chemical Engineering 2023年第3期55卷 49-58页

作者： Qiaoqiao Liu Guihong Lin Jian Zhou Liangliang Huang Chang Liu College of Chemical Engineering Nanjing Tech UniversityNanjing 210009China Zhangjiagang Institute of Nanjing Tech University Suzhou 215699China Guangdong Provincial Key Laboratory for Green Chemical Product Technology School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China School of Chemical Biological&Materials EngineeringUniversity of OklahomaNorman 73019United States

Adding Na_(2)CO_(3) to the NaHCO_(3) cooling crystallizer, using the common ion effect to promote crystallization and improve product morphology, is a new process recently proposed in the literature. However, the mechanism of the impact of Na_(2)CO_(3)on the crystal morphology is still indeterminate. In this work, the crystallization of NaHCO_(3)in water and Na_(2)CO_(3)–NaHCO_(3) aqueous solution was investigated by experiments and molecular dynamics simulations(MD). The crystallization results demonstrate that the morphology of NaHCO_(3) crystal changed gradually from needle-like to flake structure with the addition of Na_(2)CO_(3). The simulation results indicate that the layer docking model and the modified attachment energy formula without considering the roughness of crystal surface can obtain the crystal morphology in agreement with the experimental results, but the lower molecules of the crystal layer have to be fixed during MD. Thermodynamic calculation of the NaHCO_(3) crystallization process verifies that the common ion effect from Na^(+)and the ionization equilibrium transformation from CO_(3)^(2-) jointly promote the precipitation of NaHCO_(3) crystal. The radial distribution function analysis indicates that the oxygen atoms of Na_(2)CO_(3) formed strong hydrogen bonds with the hydrogen atoms of the(0 1 1) face, which weakened the hydration of water molecules at the crystal surface, resulting in a significant change in the attachment energy of this crystal surface. In addition, Na+and CO_(3)^(2-) are more likely to accumulate on the(011) face,resulting in the fastest growth rate on this crystal surface, which eventually leads to a change in crystal morphology from needle-like to flake-like.

关键词： NaHCO_(3) crystal morphology Hydrogen bond Molecular simulation

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morphology prediction of dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50) crystal in different solvent systems using modified attachment energy model

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Chinese Journal of Chemical Engineering 2023年第1期53卷 181-193页

作者： Fang Chen Tao Zhou Lijie Li Chongwei An Jun Li Duanlin Cao Jianlong Wang School of Chemical Engineering and Technology North University of ChinaTaiyuan 030051China School of Material Science and Engineering Beijing Institute of TechnologyBeijing 100081China School of Environmental and Safety Engineering North University of ChinaTaiyuan 030051China

In order to theoretically study the growth morphology of dihydroxylammonium 5,5’-bistetrazole-1,1’-dio late(TKX-50)crystal in different solvent systems,crystal–solvent models were established,and then molecular dynamics(MD)methods were adopted as a means to simulate particle motion.Modified attachment energy(MAE)model was employed to calculate the growth morphology of TKX-50.The simulation results demonstrate that COMPASS force field and RESP charge are suitable for molecular dynamics simulation of TKX-50.The morphologically dominant growth surfaces of TKX-50 in vacuum are(020),(011),(11–1),(100)and(120),respectively.In water(H_(2)O)and N,N-dimethylformamide(DMF)solvents,the(11–1)face is the largest in the habit face,the growth rate of(020)face becomes faster.With the increase of temperature,the aspect ratios of TKX-50 crystal in DMF solvent increase,and the areas of the(120)faces decrease.In ethylene glycol/H_(2)O mixed solvent system with volume ratio of 1/1,aspect ratio of TKX-50 is relatively small.In formic acid/H_(2)O mixed solvents with different volume ratios(1/4,1/3,1/2,1/1 and 2/1),aspect ratio of TKX-50 is relatively small when volume ratio is 1/2.

关键词： TKX-50 crystal morphology Solvents Modified attachment energy model Molecular dynamics simulation

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Regulation mechanism of catalyst structure on diamond crystal morphology under HPHT process

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Chinese Physics B 2020年第7期29卷 555-559页

作者：李亚东程永珊宿梦洁冉启甫王春晓马红安房超陈良超 College of Electronical Information Engineering Yangtze Normal UniversityChongqing 408100China State Key Laboratory of Superhard Materials Jilin UniversityChangchun 130012China Key Laboratory of Material Physics of Ministry of Education School of Physical EngineeringZhengzhou UniversityZhengzhou 450052China

To elucidate the regulation mechanism of catalyst geometry structure to diamond growth,we establish three catalyst modes with different structures.The simulation results show that with the decrease of the protruding height of the catalyst,the low-temperature region gradually moves toward the center of the catalyst,which causes the distribution characteristics of the temperature and convection field in the catalyst to change.The temperature difference in vertical direction of the catalyst decreases gradually and increases in the horizontal direction,while the catalyst convection velocity has the same variation regularity in the corresponding directions.The variation of temperature difference and convection velocity lead the crystal growth rate in different crystal orientations to change,which directly affects the crystal morphology of the synthetic diamond.The simulation results are consistent with the experimental results,which shows the correctness of the theoretical rational analysis.This work is expected to be able to facilitate the understanding of catalyst structure regulation mechanism on diamond morphology and the providing of an important theoretical basis for the controllable growth of special crystal shape diamond under HPHT process.

关键词： diamond single crystal growth high pressure and high temperature crystal morphology

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Preparation of Ultrafine TATB and the Technology for crystal morphology Control

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Chinese Journal of Chemistry 2012年第2期30卷 293-298页

作者： Yang,Li Ren,Xiaoting Li,Tiecheng Wang,Shiwei Zhang,Tonglai State Key Laboratory of Explosion Seience and Technology Beijing Institute of TechnologyBeijing 100081China The 42nd Institute of the Fourth Academy of China Aerospace Science and Technology Corporation Xiangyang 441003China

The ultrafine 1,3,5-triamino-2,4,6-trinitrobenzene （TATB） has been prepared by using solvent and non-solvent method, and the influencing factors in close relationship with the grain size and crystal morphology control such as categories and dosage of surfactants, volume ratio of solvent to non-solvent have also been considered in this paper. It showed that these factors had remarkable effect on the crystal morphology, particle size and agglomeration during the crystallization process. By using 0.095% （mass percentage） ionic surfactant （S） as the additive and using spray-drops feeding device as the dropping equipment, 1.06 g TATB raw materials have been refined into free-running ellipsoid and spherical TATB grains with the grain size from 30 to 50 nm. By using 0.014% （mass percentage） non-ionic surfactant （P） as the additive, spherical TATB grains with the particle diameter of 50 nm and with narrow particle-size distribution have also been obtained. It was shown by the characterizations that the ultrafine particle of TATB had better heat resisting evenness and its 5 seconds ignition point is advanced by 7.5 K.

关键词： 1,3,5-triamino-2,4,6-trinitrobenzene solvent and non-solvent method ultrafine crystal morphology crystal growth surfactants

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Effect of solvent on the crystal morphology of royal demolition explosive

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Journal of Beijing Institute of Technology 2015年第2期24卷 260-268页

作者：王东旭陈树森李燕月杨佳云魏田玉李丽洁 School of Materials Science and Engineering Beijing Institute of Technology Gansu Yinguang Chemical Industry Group Co Ltd

Important crystal faces that dominate the crystal morphology of royal demolition explosive （RDX） in vacuum were analyzed with the attachment energy （AE） method. Molecular dynamics （MD） simulations were used to calculate the interaction energies between these crystal faces and different solvent molecules for an attachment energy correction. Growth habits in the presence of different solvents were generated. The results showed that some crystal faces in solutions became morphologically more important than that in vacuum while others became less important. Thus, crystal shape and surface property changed a lot with the variation of crystal faces. The results from calcula- tion were in agreement with those from the re-crystallization experiment, which indicated that cyclohexanone （CH） was a promising solvent to modify the crystal morphology of RDX for obtaining products with regular shape and high purity, while butyrolactone （BL） played a great role in improving the surface electrostatic property of RDX.

关键词： royal demolition explosive （RDX） crystal morphology solvent molecular dynamics attachment energy

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morphology OF(Mn,Fe)S SINGLE crystal GROWTH IN CAST STEEL

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Acta Metallurgica Sinica(English Letters) 1989年第1期2卷 77-80页

作者： JIANG Xishan GONG Yansheng ZHANG Guichang Research Institute of Qiqihar Steel Works.Qiqihar,Heilongjiang,China

The step pattern of single crystal growth and the morphology at equilibrium state of(Mn, Fe)S on the wall of micro-voids in ZG25 cast steel have been observed using scanning electron microscope.The face-centred cubic(Mn,Fe)S single crystal at equilibrium state is shown to be tetrakaidecahedron consisted of eight{111}planes and six{100}planes,and is a typical example of the O_h—m3m cubic crystal system.

关键词： cast steel (Mn,Fe)S single crystal growth crystal morphology

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The characteristic morphology of benzophenone crystal

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Progress in Natural Science:Materials International 1996年第2期 109-116页

作者：仓怀兴黄卫东周尧和

The theoretical and experimental studies on the characteristic morphology of benzophenone (BP) crystal were carried out. The experimental morphology of BP crystal was enclosed by (110), (101), (111), (Oil), (021), (010) and (001) faces of which (021), (010) and (001) faces were not predicted by the morphological theory of crystal growth. This difference was due to the neglect of the waveness of face net. The studies show that BP crystal grown from its undercooled melt could reflect its characteristic morphology.

关键词： benzophenone crystal growth crystal morphology organic crystal.

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Urea-assisted morphological engineering of MFI nanosheets with tunable b-thickness

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Nano Research 2023年第10期16卷 12196-12206页

作者： Qiudi Yue Chaowei Liu Hongjuan Zhao Honghai Liu Pierre Ruterana Jiaqi Zhao Zhengxing Qin Svetlana Mintova Laboratoire Catalyse et Spectrochimie ENSICAENUNICAENCNRSCaen 14050France Petrochemical Research Institute PetroChina Company LimitedBeijing 100195China Centre de Recherche sur les Ions les Matériaux et la PhotoniqueCIMAP-ENSICAENCNRS UMR 6252Caen 14050France State Key Laboratory of Heavy Oil Processing College of Chemical EngineeringChina University of Petroleum(East China)Qingdao 266580China

Engineering of crystal morphology affects the catalytic and adsorption properties of zeolitic materials.Considering the anisotropic diffusion of molecules derived from its topological features,MFI zeolite nanosheets with short b-axis thickness are highly desired materials to reduce diffusion resistance.However,the design and development of eco-friendly synthesis protocols with reasonable cost and high efficiency remain elusive.Herein,we reported a systematic study on the synthesis of MFI nanosheets using urea as an additive.Both silicalite-1 and ZSM-5 zeolites(MFI type framework structure)with controllable b-thicknesses ranging from 50–200 nm were achieved by optimizing the synthetic parameters including water content,urea and SDA concentrations.The concentration of hydroxide anions was found to dominate the crystallization kinetics compared with the counterpart tetrapropylammonium cations(TPA^(+)).To facilitate the crystal growth of MFI zeolites in the presence of urea,the ratio OH−/SiO_(2)has to be higher than 0.2,independent of the TPA+concentration.The role of urea in the assistance of plate-like crystal formation through the inhibition of(010)facet growth was revealed by electron microscopy and infrared(IR)spectroscopy analyses.The developed strategy for morphological engineering is not limited to the MFI-type zeolite and can be applied to other frameworks depending on the intrinsic properties of additive molecules and the interactions between them.

关键词： MFI zeolite synthesis nanosheets additives crystal morphology

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Progress and prospect of hydrate-based desalination technology

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Frontiers in Energy 2022年第3期16卷 445-459页

作者： Jibao Zhang Shujun Chen Ning Mao Tianbiao He Department of Gas Engineering College of Pipeline and Civil EngineeringChina University of Petroleum(East China)Qingdao266580China

With the continuous growth of the population and the improvement of production, the shortage of freshwater has plagued many countries. The use of novel technologies such as desalination to produce fresh water on a large scale has become inevitable in the world. Hydrate-based desalination (HBD) technology has drawn an increasing amount of attention due to its mild operation condition and environmental friendliness. In this paper, literature on hydrate-based desalination is comprehensively analyzed and critically evaluated, focuses on experimental progress in different hydrate formers that have an impact on thermodynamics and dynamics in hydrate formation. Besides, various porous media promotion is investigated. Besides, the hydrate formation morphology and hydrate crystal structure with different hydrate formers are analyzed and compared. Moreover, molecular dynamic simulation is discussed to further understand microscopic information of hydrate formation. Furthermore, simulations of the HBD process by considering the energy consumption are also investigated. In conclusion, the hydrated based desalination is a potential technology to get fresh water in a sustainable way.

关键词： gas hydrates desalination crystal morphology molecular dynamic cold energy

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Theoretical study on the morphology of cobalt nanoparticles modulated by alkali metal promoters

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矿物冶金与材料学报:英文版 2023年第10期30卷 2006-2013页

作者： Xiaobin Geng Hui Yang Wenping Guo Xiaotong Liu Tao Yang Jinjia Liu National Energy Center for Coal to Liquids Synfuels China Co.LtdBeijing 101400China State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China University of Chinese Academy of Sciences Beijing 100049China Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Information Science and Technology UniversityBeijing 100101China School of Computer Beijing Information Science and Technology UniversityBeijing 100101China College of Chemistry and Environmental Science Inner Mongolia Key Laboratory of Green CatalysisInner Mongolia Normal UniversityHohhot 010022China

Cobalt nanoparticles(NPs)catalysts are extensively used in heterogeneous catalytic reactions,and the addition of alkali metal promoters is a common method to modulate the catalytic performance because the catalyst's surface structures and morphologies are sensitive to the addition of promoters.However,the underlying modulation trend remains unclear.Herein,the adsorption of alkali metal promoters(Na and K)on the surfaces of face-centered-cubic(FCC)and hexagonal-closest packed(HCP)polymorphous cobalt was systematically investigated using density functional theory.Furthermore,the effect of alkali promoters on surface energies and nanoparticle morphologies was revealed on the basis of Wulff theory.For FCC-Co,the exposed area of the(111)facet in the nanoparticle increases with the adsorption coverage of alkali metal oxide.Meanwhile,the(311),(110),and(100)facets would disappear under the higher adsorption coverage of alkali metals.For HCPCo,the Wulff morphology is dominated by the(0001)and(1011)facets and is independent of the alkali metal adsorption coverage.This work provides insights into morphology modulation by alkali metal promoters for the rational design and synthesis of cobalt-based nanomaterials with desired facets and morphologies.

关键词： cobalt nanoparticles alkali promoter density functional theory crystal morphology Wulff construction

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