物理化学学报(WuliHuaxueXuebao)
ActaP坶豇一Chim.Sin.,2010,26(2):422-428 February
【Article】 WWW.whxb.pku.edu.ell
阴离子表面活性剂在水/正烷烃界面的分子动力学模拟
肖红艳1,。 甄珍1 孙焕泉2 曹绪龙2 李振泉z
宋新旺z 崔晓红2 刘新厚·,+
(·中国科学院理化技术研究所,光化学转换与功能材料重点实验室,北京 100190;
。中石化胜利油田分公司地质科学研究院,山东东营257001)
摘要:利用分子动力学模拟方法研究了阴离子表面活性剂在水/正烷烃(壬烷,癸烷和十一碳烷)界面的结构和
动力学特点.十六烷基苯磺酸钠作为研究对象,其中苯磺酸基团在十六碳烷的第4号碳原子上,记作4-C16.分
析了不同油相和特定盐度条件下正烷烃.表面活性剂一水体系的界面特点(如密度剖面图、界面张力和径向分布函
数).模拟结果表明平衡模型体系展现了一个很好的水,正烷烃界面.当加氯化钠到水溶液中,正烷烃一表面活性
剂一水体系的界面张力有微小的变化,有趣的是表面活性剂二面角的反式结构分数的变化联系着界面张力的微
小变化.可见,表面活性剂在界面处的结构对降低界面张力起到重要的作用.此外,还发现表面活性剂的极性头
与钠离子和水分子存在较强的相互作用.
关键词:分子动力学;水/正烷烃界面;阴离子表面活性剂;界面张力;反式结构分数
中图分类号:0641;0647
MolecularDynamicsSimulationofAnionicSurfactantat
theWater/n.AlkaneInterface
XIAOHong—Yanlt+ZHENZhenlSUNHuan-Quail2CAOXu—Lon92LIZhen—Quan
SONGXin-Wan92CUIXiao—Hon92LIUXin-Houl·+
(1KeyLaboratoryofPhotochemicalConvemionandOptoelectronicMaterials,TechnicalInstituteof砌声icsandChemistry,
ChineseAcademyofSciences,BeOmg100190,P.R.China;21nstituteofGeologicalScience,ShengliOilfieldLtd.Co.。
Dongying257001.ShandongProvince.P.R.China、
Abstract:Thestructuralanddynamicpropertiesofanionicsurfactantatthewater/n.alkane(nonane,decane,and
undecane)interfacewereinvestigatedbythemoleculardynamicssimulation.Themodelanionicsurfactantcontaineda
benzenesulfonategroupattachedtOthe4thcarboninthehexadecanebackboneandwasdenoted私事C16.We
analyzedtheinterfacialproperties(densityprofile,inteffacialtension,andradialdistributionfunction)ofthen—alkane—
surfactant-watersystemsindifferentoilphasesandunderspecialinorganicsalinityconditions.Thesimulationresults
indicatetllatawell—definedinterfaceexistsbetweenthen-alkaneandwaterphasesintheequilibratedmodelsystems.
Theinterfacialtensionsofthen.alkane.surfaetant.watersystemsshowlittlechangewhensodiumchlorideisaddedtO
thesolutions.、Ⅳefindthatachangein山etrans.formfractionof山edihedralin4-C16isrelatedtoasubtlechangein
theinterfacialtensionattllewater/n.aloeintefface.Clearly.thestructureofthesurfactantattheinterfaceplaysan
importantroleinreducingtheinterfacialtension.Inaddition.wealsofindthatthepolarheadgroupofthesurfactant
moleculeswithsodiumiOilsandwatermoleculesundergostrongerinteractions.
KeyWords:Moleculardynamics;Water/n-alkaneinterface;Anionicsurfactant;Interfacialtension;
trans-formfraction
Received:September29,2009;Revised:December1。2009;PublishedOilWeb:December23,2009.
‘Correspondingauthors.Email:hyxiao@mail.ipc.ac.ca,zhenz@mail.ipc.ac.cn;Tel:+86-10-82543529
⑥EditorialofficeofActaPhysico-ChimicaSinica
万方数据
No.2 XIAOHong.Yaheta1.:MolecularDynamicsSimulationofAnionicSurfactantattheWater/n.AlkaneIntefface423
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crudeoilrecovery.11地mainfunctionofthesurfactantistore.
ducetheinterfacialtensionbeaconoiJandwatertoanultra.)ow
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