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Molecular simulation of oligomer inhibitors for calcite scale

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Particuology 2012年第3期10卷 266-275页

作者： Qiuyu zhang Hua Ren Wenwen Wang Junping zhang hepeng zhang School of Science Northwestern Polytechnical UniversityXi'an 710072China

Molecular simulation was performed to study the interaction between CaCO3 crystal and several oligomer inhibitors, by using the equilibrium morphology method to calculate the growth morphology of CaCO3 without inhibitors. The calculated morphology agreed well with SEM photographs. Then, a double-layer model was built to investigate the interaction between calcite crystal and oligomer inhibitors containing maleic anhydride （MA） and acrylic acid （AA）. Interaction energy per gram of an oligomer inhibitor was introduced as a scale of inhibition efficiency of different monomers. The results indicated that, for calcite scale inhibition, acrylamide （AM） and vinyl phosphonic acid （VPA） were the most efficient monomers, while allylsulfonic acid （AS） was the poorest. Increasing proportion of AM in dimer inhibitor molecule would improve the inhibition efficiency of MA, though, for a trimer, such as MA-AA-AM, certain sequence of monomers in the inhibitor molecule was necessary besides higher proportion of AM.

关键词： Molecular simulationCrystal morphology Interaction energy Scale inhibitorScale inhibition efficiency

Symmetry properties of fluctuations in an actively driven rotor

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Chinese Physics B 2020年第6期29卷 25-29页

作者： He Li Xiang Yang hepeng zhang School of Physics and Astronomy and Institute of Natural Sciences Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of Advanced Microstructures Nanjing 210023China

We investigate rotational dynamics of an actively driven rotor through experiments and numerical simulations. While probability density distributions of rotor angular velocity are strongly non-Gaussian, relative probabilities of observing rotation in opposite directions are shown to be linearly related to the angular velocity magnitude. We construct a stochastic model to describe transitions between different states from rotor angular velocity data and use the stochastic model to show that symmetry properties in probability density distributions are related to the detailed fluctuation relation(FR) of entropy productions.

关键词： Brownian motor active bath fluctuation relation active matter

Key synthesis of magnetic Janus nanoparticles using a modified facile method

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Particuology 2014年第6期12卷 59-65页

作者： Nisar Ali Baoliang zhang hepeng zhang Wajed Zaman Wei Li Qiuyu zhang Key Laboratory of Applied Physics and Chemistry in Space of Ministry of Education School of ScienceNorthwestern Polytechnical University School of Material Science & Engineering Northwestern Polytechnical University

Inorganic/organic poly（methylmethacrylate-acrylic acid-divinylbenzene） iron oxide Janus magnetic nanoparticles（P（MMA-AA-DVB）/Fe3O4） with strong magnetic domains and unique surface functionalities were prepared using a solvothermal *** P（MMA-AA-DVB） nanoparticles were prepared via soapfree emulsion polymerization and used as a precursor for preparing Janus *** morphology and magnetic properties of the magnetic Janus nanoparticles formed were characterized using a laser particle size analyzer,transmission electron microscopy,Fourier transform infrared spectroscopy,vibrating sample magnetometry,and thermogravimetric *** synthesized P（MMA-AA-DVB）/Fe3O4 magnetic Janus nanoparticles were characterized by a Janus structure and possessed a stable asymmetric morphology after being dually *** particle size,magnetic content,and magnetic domain of the P（MMA-AA-DVB）/Fe3O4 magnetic Janus nanoparticles were 200 nm,40%,and 25 emu/g,*** formation mechanism of the Janus nanoparticles was also investigated,and the results revealed that the reduction of Fe3＋ ions and growth of Fe3O4 took place on the surface of the P（MMA-AA-DVB） polymeric precursor *** size of the Janus particles could be controlled by narrowing the size distribution of the P（MMA-AA-DVB） precursor nanoparticles.

关键词： Janus Magnetic nanoparticles Solvothermal process Composite Emulsion polymerization

Preparation of SiO_2/TiO_2 Janus particles by electrostatic assembly,hydrolysis and calcination

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Particuology 2013年第5期11卷 574-580页

作者： Baoliang zhang Qiuyu zhang hepeng zhang Xinlong Fan Dezhong Yin Xiangjie Li Wei Li Department of Applied Chemistry College of ScienceNorthwestern Polytechnical University

This paper describes a novel chemical method for preparing SiO2/TiO2 Janus particles. First, polystyrene （PSt）/SiO2 particles with a raspberry-like structure are prepared by electrostatic assembly. The influences of the reaction time of sulfonation and the treatment times of polyelectrolyte solutions （PDADMAC, PSS） on PSt and SiO2 are investigated with respect to the surface charge density of the particles. SiO2/TiO2 Janus particles are then obtained by hydrolysis of butyl titanate on the surface of PSt/SiO2 particles followed by a calcination process. Particle size analyzer, Zeta potential instrument, FTIR, TEM and SEM are used to characterize the particle size, the amount of charge on the surface of PSt and SiO2 particles and the compositions and morphologies of PSt/SiO2, SiO2/Ti02 and PSt/SiO2/Ti02. The diameters of the PSt, SiO2, PSt/Si02 and SiO2/Ti02 particles are 2.0 t^m, 303 nm, 2.7 bcm and 330 nm, respectively.

关键词： Janus particlesElectrostatic assemblyHydrolysisCalcination

Synthesis of PS/Ag asymmetric hybrid particles via phase separation and self-assembly

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Particuology 2013年第6期11卷 768-775页

作者： Xinlong Fan Qiuyu zhang hepeng zhang Baoliang zhang Chunmei Li Xiangjie Li Xingfeng Lei Key Laboratory of Applied Physics and Chemistry in Space of Ministry of Education School of ScienceNorthwestern Polytechnical University

This article presents a facile approach to preparation of polystyrene/silver （PS/Ag） asymmetric hybrid par- ticles. In this method, polystyrene/polyglycidyl methacrylate （PS/PGMA） Janus particles were synthesized via internal phase separation triggered by evaporation of dichloromethane （DCM） from PS/PGMA/DCM- in water emulsion droplets. Then, the Janus particles were aminated and sequentially carboxylated to obtain PS/PGMA-NH2 and PS/PGMA-COOH particles. Ag＋ self-assembled on the surface of PGMA hemi- sphere of the functionalized PS/PGMA particles by coordinating with amine/carboxyl. PS/Ag asymmetric hybrid particles with 7.29 wt% of Ag were obtained by reduction of Ag＋, Scanning electron microscopy, energy-dispersive X-ray spectroscopy and transmission electron microscopy results confirmed that Ag was asymmetrically distributed on the surface of polymer particles.

关键词： Phase separation Interracial interaction Amination Carboxylation Coordination Self-assembly

Separation and recovery of rare earth from waste nickel-metal hydride batteries by phosphate based extraction-precipitation

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Journal of Rare Earths 2022年第6期40卷 974-980,I0005页

作者： Hailan Zhi Shuainan Ni Xiang Su Wenqi Xie hepeng zhang Xiaoqi Sun College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China Fujian CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian Research Center for RE Engineering Technology Xiamen Institute of RE MaterialsHaixi InstituteChinese Academy of SciencesXiamen 36102JChina Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou 341000China Ganzhou Rare Earth Group Co. Ltd.China Southern Rare EarthGanzhou 341000China

A novel type of extraction-precipitation strategy based on phosphate was developed to recover rare earth(RE,i.e.,La,Ce,Nd,and Pr)from waste nickel-metal hydride(NiMH)*** method does not require saponification and organic *** novel phosphates,i.e.,dibenzyl phosphate(DBP),diphenyl phosphate(DPP),triphenyl phosphate(TPP)were studied as *** has high precipitation efficiencies for RE^(3+),which can reach 97.84%,100%,100%and 99.77%,*** addition,the precipitation efficiencies of Mn^(2+),Co^(2+)and Ni^(2+)are less than 1.75%.DBP-RE has the largest particle size(D10=52.6μm,D50=135.35μm,D90=296.08μm),which is much larger than the precipitations formed by NH_(4)HCO_(3),H_(2)C2O_(4),CaO and *** larger precipitation particle sizes contribute to improving the solid-liquid separation *** 3 mol/L hydrochloric acid,the stripping efficiency of DBP-RE reaches 98.60%,and the purity of recovered RE is 99.85%.The regenerated DBP can be directly used for the recycling ***,the novel extraction-precipitation strategy is a green and sustainable separation method.

关键词： Waste nickel-metal hydride battery Rare earth Extraction-precipitation Phosphonic acid(ester)

Separation of aluminum from rare earth by solvent extraction with 4-octyloxybenzoic acid

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Journal of Rare Earths 2023年第2期41卷 290-299页

作者： Gaoshan Yu Zhiyuan Zeng Yun Gao Shuainan Ni hepeng zhang Xiaoqi Sun CAS Key Laboratory of Design and Assembly of Functional Nanostructures Fujian Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian Research Center for Rare Earth Engineering Technology Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100039China Jiangxi Province Key Laboratory of Cleaner Production of Rare Earths Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou 341000China

Leaching method is usually used to extract rare earth(RE)elements from ion adsorbed RE *** the leaching process,some impurities such as aluminum(Al)enter the leaching *** separation of Al from RE by carboxylic acid extractant 4-octyloxybenzoic acid(POOA)was studied in this *** changing the pH value,temperature,solvent,saponification degree and other parameters,the extraction and separation performance of POOA in chloride system was systematically *** specific extraction experiments and slope analysis,it can be seen that the stoichiometric ratio of POOA to Al is 3:1during the extraction *** separation factor of Al^(3+)and Pr^(3+)can reach about *** with easily emulsified naphthenic acid,POOA achieves better phase *** above results show that saponified POOA(S-POOA)has a good separation effect on Al and *** the condition of low concentration stripping acid of 0.60 mol/L HCl,the developed extraction system can be almost completely stripped,and the stripping rate reaches 97.52%.The regenerated POOA can be directly used for the recycling extraction.

关键词： Rare earths Aluminium 4-octyoxybenzoic acid Solvent extraction Separation

Insight into Ce Doping Induced Oxygen Vacancies over Ce-Doped MnO2 Catalysts for Imine Synthesis

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Chinese Journal of Chemistry 2020年第11期38卷 1353-1359页

作者： Haidong Shen Jun Bu Wenbin Wang Chen Wu Yueling Cao Baoliang zhang Qiuyu zhang hepeng zhang Laboratory of Special Functional&Smart Polymer Materials School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi'anShaanxi 710129China

of main observation and conclusion The pursuit of modern sustainable chemistry has stimulated the development of innovative catalytic processes that enable chemical transformations to be performed under mild and clean conditions with high ***,an amorphous sheet-like MnO2(Ce-doped MnO2:CMBO)was obtained after Ce doping,which exhibits excellent catalytic performance for the oxidation coupling of alcohol and *** of 99%and a selectivity of 99%could be achieved within 6 h at 60℃under air atmosphere,and the formation rate of target product was up to 30.2 nmol h^-1·m^-*** on a series of characterizations,it was found that the doping of Ce into the MnO2 could increase the concentration of the oxygen vacancies,thus forming abundant active surface oxygen species and favoring the mobility of lattice oxygen,which are the main reasons for the greatly enhanced catalytic performance of *** work indicates that increasing oxygen vacancy by element doping may serve as a facile and effcient way to enhance catalytic performance of transition metal oxide.

关键词： doping Oxygen aniline

A series of nanoparticles with phase-separated structures by 1,1-diphenylethene controlled one-step soap-free emulsion copolymerization and their application in drug release

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Nano Research 2017年第9期10卷 2905-2922页

作者： Xinlong Fan Jin Liu Xiangkun Jia Yin Liu Hao zhang Shenqiang Wang Baoliang zhang hepeng zhang Qiuyu zhang Department of Applied Chemistry School of Natural and Applied Sciences Northwestern Polytechnical University No. 127 WestYouyi Road Xi'an 710072 China

A facile one-step approach to synthesize various phase-separated porous, raspberry-like, flower-like, core–shell and anomalous nanoparticles and nanocapsules via 1,1-diphenylethene (DPE) controlled soap-free emulsion copolymerization of styrene (S) with glycidyl methacrylate (GMA), or acrylic acid (AA) is reported. By regulating the mass ratio of S/GMA, transparent polymer solution, porous and anomalous P(S-GMA) particles could be produced. The P(S-GMA) particles turn from flower-like to raspberry-like and then to anomalous structures with smooth surface as the increase of divinylbenzene (DVB) crosslinker. Transparent polymer solution, nanocapsules and core–shell P(S-AA) particles could be obtained by altering the mole ratio of S/AA; anomalous and raspberry-like P(S-AA) particles are produced by adding DVB. The unpolymerized S resulted from the low monomer conversion in the presence of DPE aggregates to form nano-sized droplets, and migrates towards the external surfaces of the GMA-enriched P(S-GMA) particles and the internal bulk of the AA-enriched P(S-AA) particles. The nano-sized droplets function as in situ porogen, porous P(S-GMA) particles and P(S-AA) nanocapsules are produced when the porogen is removed. This novel, facile, one-step method with excellent controllability and reproducibility will inspire new strategies for creating hierarchical phase-separated polymeric particles with various structures by simply altering the species and ratio of comonomers. The drug loading and release experiments on the porous particles and nanocapsules demonstrate that the release of doxorubicin hydrochloride is very slow in weakly basic environment and quick in weakly acidic environment, which enables the porous particles and nanocapsules with promising potential in drug delivery applications.

关键词： phase separation 1,1-diphenylethene controlled polymerization porous nanocapsules controlled release