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1、分子模拟在化工中的应用摘要:随着高技术学科的飞速进步,化工学科在多年来已形成的理论和实验研究之外,又产生了一种完全独立而新颖的研究手段——分子模拟。目前化学工业受关注的新技术涉及聚合物、电解质等复杂物质,临界、超临界等复杂状态,界面、膜、溶液等复杂现象。实现化学工业从产品到过程设计完全自动化,在这些方面除了准确的物性数据外,更要对各种复杂现象的机理有深刻了解。分子模拟被认为是实现这一目标的关键技术之一。本文以分子动力学为主,结合计算量子化学,对分子模拟在化工应用中的若干问题进行讨论。Abstract:Withthedevelopmen
2、tofhigh-technology,molecularsimulation,whichisnovelbothintheoryandexperiment,hasbeenappliedinchemicalengineering.Thenewtechnologiesinchemicalindustryincludesuchcomplexmaterialsaspolymerandelectrolyte,suchcomplexconditionsascriticalandsupercritical,andsuchcomplexphenomen
3、onasinterface,membraneandsolution.Toachievethevisionofcompletelyautomatedproductandprocessdesigninchemicalindustry,thepropertiesofthematerialsandthemechanismofthephenomenashouldbeaccuratelyobtained.Theexpectationsformolecularsimulationareveryhigh,becauseithasbeenidentif
4、iedasoneofthekeymethodsfordeterminingthesepropertiesandphenomena.Inthispaper,thekeyproblemsofmolecularsimulationinchemicalengineeringespeciallybasedonmoleculardynamics(MD)andquantumchemistry(QC)arediscussed.TheyincludepotentialmodelofMD,scaleofMD,theconnectionofmulti-sc
5、aleMD,analysisofMDresults,constructionofareasonableinitialconfigurationandsoftware&hardwareofMD.Severalpromisingguidesareproposedtosolvetheabovekeyissues.ComputationalquantumchemistrysoftwaresuchasGaussian98couldbeutilizedtoacquirethemissinginteractionparameters.Asforpo
6、tentialmodelitisnotnecessarytousethemostcomplexonetodescribetheinteractionbetweenparticles.Sometimessimplemodelsaregoodenoughtocalculatecertainproperties.SomenewtechniquesaredevelopedtoenlargethesystemofMDatdifferentscales.Forexample,thedensityfunctionaltheory(DFT)madet
7、heQCcalculationforhundredsOfatomspossiblewhiledissipativeparticledynamics(DPD)extendedthesystemofMDtomesoscale.ThegeneraltrendofmolecularsimulationistocombineQC,MDandmesoscaledynamicsmoreclosely,andmanymulti-scaleMDmethodssuchasCar-ParrinelloMD(CPMD)woulddefinitelybecom
8、estrongerandstronger.ItisindispensabletodefineasuitablestatisticalvariabletoanalyzethetrajectoryofMD,andthetri