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Asphaltenes: separations, structural analysis and applications

Journal of Energy Chemistry 2019年第7期28卷 186-207页

作者： Pingping Zuo Shijie Qu Wenzhong Shen State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences

Asphaltenes, complex aromatic compounds from various carbonaceous sources, could be obtained by solvent dissolution, filtration and adsorption. It was difficult to clarify the molecular structures and chemical properties of asphaltene due to its structural similarity, composition complexity and source dependences. Many techniques, like Mass spectrometry, Chromatography, Nuclear magnetic resonance spectroscopy, Infrared spectroscopy, Roman spectroscopy, Fluorescence spectroscopy, X-ray diffraction analysis and Small-angle scattering techniques and so on, have revealed some valuable descriptions of asphaltenes chemical compositions and fundamental structures. Moreover, advanced Mass spectrometry,Atomic force microscopy and Scanning tunneling microscopy could provide more clear and essential molecular compounds and structures in asphaltenes. In addition, several asphaltenes models have succeeded to illustrate aggregation properties asphaltene. In this work, the progress on asphaltene separation, characterization and application was summarized, and the similarities and differences between coal-derived asphaltenes and petroleum asphaltenes were compared. Furthermore, the reactivity of asphaltenes has been discussed in the aspect of hydroprocessing, pyrolysis and gasification. Asphaltene was excellent carbon precursor for functional carbon material due to its high aromaticity and carbon yield;several porous carbon nanosheets from asphaltenes that would be prospective electrode materials after being graphitized were shown. Pitch-based carbon fiber derived from coal-derived asphaltenes displayed a tensile strength of 1.0 GPa and elastic modulus of 350 MPa, respectively. These powerful advances will provide asphaltenes promising developments.

关键词： Asphaltenes separations Structures Aggregation Applications

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Advancing ion-exchange membranes to ion-selective membranes:principles,status,and opportunities

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Frontiers of Environmental Science & Engineering 2023年第2期17卷 145-171页

作者： Hanqing Fan Yuxuan Huang Ngai Yin Yip Department of Earth and Environmental Engineering Columbia UniversityNew YorkNY 10027-6623USA Columbia Water Center Columbia UniversityNew YorkNY 10027-6623USA

Ion-exchange membranes(IEMs)are utilized in numerous established,emergent,and emerging applications for water,energy,and the environment.This article reviews the five different types of IEM selectivity,namely charge,valence,specific ion,ion/solvent,and ion/uncharged solute selectivities.Technological pathways to advance the selectivities through the sorption and migration mechanisms of transport in IEM are critically analyzed.Because of the underlying principles governing transport,efforts to enhance selectivity by tuning the membrane structural and chemical properties are almost always accompanied by a concomitant decline in permeability of the desired ion.Suppressing the undesired crossover of solvent and neutral species is crucial to realize the practical implementation of several technologies,including bioelectrochemical systems,hypersaline electrodialysis desalination,fuel cells,and redox flow batteries,but the ion/solvent and ion/uncharged solute selectivities are relatively understudied,compared to the ion/ion selectivities.Deepening fundamental understanding of the transport phenomena,specifically the factors underpinning structure-property-performance relationships,will be vital to guide the informed development of more selective IEMs.Innovations in material and membrane design offer opportunities to utilize ion discrimination mechanisms that are radically different from conventional IEMs and potentially depart from the putative permeability-selectivity tradeoff.Advancements in IEM selectivity can contribute to meeting the aqueous separation needs of water,energy,and environmental challenges.

关键词： Ion-exchange membranes Selectivity separations

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Efficient and accurate online estimation algorithm for zero-effort-miss and time-to-go based on data driven method

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Chinese Journal of Aeronautics 2019年第10期32卷 2311-2323页

作者： Hongxia LI Huijie LI Yuanli CAI School of Electronic and Information Engineering Xi’an Jiaotong University

This paper introduces a novel and efficient algorithm for online estimation of zero-effortmiss and time-to-go based on data driven method.Only missile-target separations are utilized to construct the estimation models,and a practical Fisher fusion algorithm is derived to acquire the estimates with high accuracy and computational efficiency.Further,the two parameters can be online estimated at a particular time.Meanwhile,the kinematics equations of the missile-target engagement are independent,and assumptions of the missile guidance system dynamics and behaviors of the missile and target are completely out of consideration.Moreover,the effectiveness and applicability are explicitly verified through various simulation scenarios.

关键词： Data driven Missile-target separations Online estimation Time-to-go Zero-effort-miss

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Functional Capsules Encapsulating Molecular-Recognizable Nanogels for Facile Removal of Organic Micro-Pollutants from Water

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Engineering 2021年第5期7卷 636-646页

作者： Wen-Ying Liu Xiao-Jie Ju Xing-Qun Pu Quan-Wei Cai Yu-Qiong Liu Zhuang Liu Wei Wang Rui Xie Liang-Yin Chu School of Chemical Engineering&State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengdu 610065China

A novel method has been successfully developed for the facile and efficient removal of organic micro-pollutants(OMP)from water based on novel functional capsules encapsulating molecular-recognizable nanogels.The functional capsules are composed of ultrathin calcium alginate(Ca-Alg)hydrogel shells as semipermeable membranes and encapsulated poly(N-isopropylacrylamide-co-acrylic acid-g-mono-(6-ethanediamine-6-deoxy)-β-cyclodextrin)(PNCD)nanogels withβ-cyclodextrin(CD)moieties as OMP capturers.The semipermeable membranes of the capsules enable the free transfer of OMP and water molecules across the capsule shells,but confine the encapsulated PNCD nanogels within the capsules.Bisphenol A(BPA),an endocrine-disrupting chemical that is released from many plastic water containers,was chosen as a model OMP molecule in this study.Based on the host–guest recognition complexation,the CD moieties in the PNCD nanogels can efficiently capture BPA molecules.Thus,the facile and efficient removal of BPA from water can be achieved by immersing the proposed functional capsules into BPA-containing aqueous solutions and then simply removing them,which is easily done due to the capsules’characteristically large size of up to several millimeters.The kinetics of adsorption of BPA molecules by the capsules is well described by a pseudo-second-order kinetic model,and the isothermal adsorption thermodynamics align well with the Freundlich and Langmuir isothermal adsorption models.The regeneration of capsules can be achieved simply by washing them with water at temperatures above the volume phase transition temperature of the PNCD nanogels.Thus,the proposed functional capsules encapsulating molecular-recognizable nanogels provide a novel strategy for the facile and efficient removal of OMP from water.

关键词： Functional capsules Molecular-recognizable nanogels Organic micro-pollutants Host-guest complexation separations

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Old and new concepts based on coherent structures for understanding sediment transport

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International Journal of Sediment Research 2011年第3期26卷 376-384页

作者： Albert GYR Inst.of Hydromechanics and Water Resources Management Swiss Federal Institute of TechnologyCH-8093Swiss

Coherent structures develop due to an instability process on smooth beds under turbulent flow conditions and they are relevant for the incipient motion of fine sand sediment.Similar flow structures were found to be relevant for the sediment transport under rough wall conditions,but an instability process could not explain them.In this article we show that rough walls produce a new class of A-vortices,these vortices develop from separations on the grains,and are new relevant flow structures.

关键词： Sediment transport Incipient motion Coherent structures Turbulence separations

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Using both small particle size HPLC packings and unique stationary phases for improved resolution in challenging separations

Using both small particle size HPLC packings and unique stat...

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30th International Symposium on Capillary Chromatography、4th GC×GC Symposium、16th National Symposium and Exhibition on Chromatography,i.e. 1st Dalian International Symposium and Exhibition on Chromatography

作者： Dorman,F.L. Romesberg,R.L. Lake,R.J. Aibright,B.A. Wittrig,R.E. Restek Corporation 110 Benner Circle BellefontePA 16823 Restek Corporation 110 Benner Circle BellefontePA 16823 Restek Corporation 110 Benner Circle BellefontePA 16823 Restek Corporation 110 Benner Circle BellefontePA 16823 Restek Corporation 110 Benner Circle BellefontePA 16823

＜正＞Until recently,the use of small particles（i.***.less than 3μm in diameter）was not practical because of the pressure limitations of commercially available HPLC pumps.With multiple ultra high pressure systems now available,columns packed with small particles are generating a significant amount of interest.According to the van Deemter Equation,which relates flow rate to column efficiency,when particle size is decreased large gains in efficiency can theoretically be achieved.Additionally,a flatter efficiency profile allows for a wider range of flow rates without significant loss of resolution.

关键词： HPLC LC Columns separations

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Measurement and correlation of supercritical CO_(2) and ionic liquid systems for design of advanced unit operations

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Frontiers of Chemical Science and Engineering 2009年第1期3卷 12-19页

作者： Hiroshi MACHIDA Ryosuke TAGUCHI Yoshiyuki SATO Louw J.FLORUSSE Cor J.PETERS Richard L.SMITH Department of Chemical Engineering Research Center of Supercritical Fluid TechnologyTohoku UniversitySendaiJapan Graduate School of Environmental Studies Tohoku UniversitySendaiJapan Laboratory of Applied Thermodynamics and Phase Equilibria Faculty of Applied SciencesDelft University of TechnologyJulianalaan 1362628 BL DelftThe Netherlands Laboratory of Process Equipment Department of Process and EnergyFaculty of MechanicalMaritime and Materials EngineeringDelft University of TechnologyLeeghwaterstraat 442628 CA DelftThe Netherlands Petroleum Institute Chemical Engineering ProgramBu Hasa BuildingRoom 2203P.O.Box 2533Abu DhabiUnited Arab Emirates

Ionic liquids combined with supercriticalﬂuid technology hold great promise as working solvents for developing compact processes.Ionic liquids,which are organic molten salts,typically have extremely low volatility and high functionality,but possess high viscos-ities,surface tensions and low diffusion coefﬁcients,which can limit their applicability.CO_(2),on the other hand,especially in its supercritical state,is a green solvent that can be used advantageously when combined with the ionic liquid to provide viscosity and surface tension reduction and to promote mass transfer.The solubility of CO_(2) in the ionic liquid is key to estimating the important physical properties that include partition coefﬁcients,viscosities,densities,interfacial tensions,thermal conductivities and heat capacities needed in contactor design.In this work,we examine a subset of available high pressure pure component ionic liquid PVT data and high pressure CO_(2)-ionic liquid solubility data and report new correlations for CO_(2)-ionic liquid systems with equations of state that have some industrial applications including:(1)general,(2)fuel desulfurization,(3)CO_(2) capture,and(4)chiral separation.New measurements of solubility data for the CO_(2) and 1-butyl-3-methylimidazolium octyl sulfate,[bmim][OcSO4]system are reported and correlated.In the correlation of the CO_(2) ionic liquid phase behavior,the Peng-Robinson and the Sanchez-Lacombe equations of state were considered and are compared.It is shown that excellent correlation of CO_(2) solubility can be obtained with either equation and they share some common characteristics regarding inter-action parameters.In the Sanchez-Lacombe equation,parameters that are derived from the supercritical region were found to be important for obtaining good correlation of the CO_(2)-ionic liquid solubility data.

关键词： compact processes chiral ionic liquids separations thermodynamic properties equations of state

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Variation in Levels of Flavonols Myricetin, Quercetin and Kaempferol—In Kenyan Tea (<i>Camellia sinensis L.</i>) with Processed Tea Types and Geographic Location

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Open Journal of Applied Sciences 2021年第6期11卷 736-749页

作者： Simon Mwangi Kingori Simon Oduor Ochanda Robert Kipyegon Koech Kenya Agricultural and Livestock Research Organization Tea Research Institute (KALRO) Kericho Kenya

The aim of this study was to determine the levels of myricetin, quercetin, and kaempferol in green and black Kenyan types in relation to geographic location of production. Tea samples were extracted before chromatographic separations with a Shimadzu 20A HPLC coupled with PDA. Flavonol levels were quercetin > kaempferol > myricetin. Teas from east of rift, had quercetin 1.25-1.83 mg/g and 1.29-1.71 mg/g for green and black types, respectively. Kaempferol levels were between 1.28-1.72 mg/g in green and 1.36-1.76 mg/g in black tea. Myricetin ranged at 0.40-0.79 mg/g green and 0.12-0.38 mg/g black tea types. Total flavonols in green tea were highest at 4.28 mg/g while black tea was 3.83 mg/g. These trends agree well with those observed in teas west of the rift. For tea types, myricetin and kaempferol showed a significant difference (P

关键词： Samples Extracted Chromatographic separations

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Microfluidic Approaches for Cancer Cell Separation: Review

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Journal of Biomedical Science and Engineering 2014年第12期7卷 1005-1018页

作者： Omer Osman Saeed Rui Li Yulin Deng School of Life Science Beijing Institute of Technology Beijing China

This article reviews the recent developments in microfluidic technologies for in vitro cancer diagnosis. We summarize the working principles and experimental results of microfluidic platforms for cancer cell detection, and separation based on magnetic activated micro-sorting, and differences in cellular biophysics (e.g., cell size and dielectrophoresis (DEP)).

关键词： Microfluidic Cancer Cell Detentions separations

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