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1、有机核反离子中羟基对氟表面活性剂性能的影响张甜甜I,邢航,胡鹏斌I,件博万I,肖进新L”1.陇东学院化学化工学院工业表面活性剂协同创新中心,陇东学院一氟乐邦表面活性剂工程技术中心,庆阳7450002.北京籁乐邦表面活性剂技术研究所北京Iooo96摘要:氟表面活性剂是一种重要的特种表面活性剂。对于离子型的氟表面活性剂,反离子不仅影响其溶解性(如Krafft点),也影响其表面活性。这里分别测定氟表面活性剂C7R5COCN+H(C2H5)3MC2H4OH),X=0,1,2,3和C8B7SO3-N+H(C2H5)3MC2H4OHh,X=O,1,2,3在25的表面张力和发泡倍数,从而研究有机较类反离子中
2、羟基数目对全氟辛酸盐/全氟辛基磺酸盐表面活性的影响。结果表明,反离子对两者的影响表现出相同的规律,即随着反离子中羟基数目的增加,临界胶束浓度(cmc)与CmC处的表面张力(加徵)均增大,这可通过疏水效应的降低以及空间位阻的增大来解释:羟基为亲水性基团,在反离子中引入羟基降低了反离子的疏水性,减弱了反离子在气水界面和胶团表面的吸附趋势;另外,羟基的引入还增大了反离子的空间位阻(空间体积),同时反离子电荷密度亦下降,降低了反离子在气水界面和胶团表面的吸附密度。以上原因均可导致静电屏蔽作用的下降,使得Cmc、%nc均明显增大。最后,从气水界面吸附层的外表面的基团性质的角度来看,由于羟基的引入,可能使
3、得界面层的水渗透加剧,这也可能导致溶液的yc,nc增大。对于所研究的表面活性剂体系,发泡倍数的实验结果规律性不强。推测原因是由于泡沫的影响因素较为复杂,除了气液界面分子排列的紧密度,还可能与表面活性剂溶液的粘度、液膜含水量等多种因素有关。关键词:反离子;有机镂离子;碳氟表面活性剂;泡沫;表面活性;胶束化EffectsofhydroxylgroupsinorganicammoniumcounterionsonthepropertiesoffluorinatedsurfactantsZHANGTian-tianl,XINGHang12,HUPeng-binl,WUBo-wanl,XIAOJin-x
4、inl21第一作者:张甜甜(1987-),女,陕西榆林人,硕士/讲师,主要研究方向为应用化学。通讯作者(ColTeSPOndingaUthor):肖进新(1963-),甘肃民勤人,教授,博士, E-mail:,电话甘肃省应用化学省级重点学科建设项目(GSACKS)和陇东学院博士基金(NoXYBY07)资助。Supl)rted by the AppliedChemistry Key Subject of Gansu Province (No. GSACKS) and the Doctor Foundation of Longdong University(No. XYBY07).1. LONGD
5、ONGUNIVERSITY-FLUOBONSurfactantEngineeringTechnologyCenter,CollegeofChemistry&ChemicalEngineering,CooperativeInnovationCenterofIndustrialSurfactant,LOngdOngUniversity,Qingyang745000,China;2. BeijingFLUOBONSurfactantInstitute,Beijing100096,China.Abstract:Fluorinatedsurfactantsareanimportantclassofspe
6、cialsurfactants.Asforionicfluorinatedsurfactants,thecounterionscouldbothinfluencethesolubilityandsurfaceactivityofsurfactants.Herein,thesurfacetensionandfoamingabilityforC7F15COO-N+H(C2H5)3C2H4OH)andC8Fl7SO3N+H(C2H5)3C2H4OH)(=0,1,2,3)weremeasuredat25,tosystematicallystudytheeffectsofhydroxylgroupsin
7、organicammoniumcounterionsonthesurfaceactivitiesofsurfactantsofperfluorooctanoatesandperfluorooctanesulfonates.Theresultsshowedthat,thecriticalmicelleconcentration(cmc)andthesurfacetensionatcmc(ycn)werebothincreasedwiththeincreaseofnumberofhydroxylgroups(x)inthetwoseries.Itcouldbeexplainedbythedecre
8、asedhydrophobicityandtheincreasedstericeffect,whichcouldmakethescreeningonelectrostaticinteractionslesseffective:thehydroxylgroupsarehydrophilic,thustheadsorptiontendenciesofcounterionsontotheair-waterinterfaceandmicellarsurfacewerebothreducedwhenhydroxylgroupswereintroduced;Additionally,thehydroxyl
9、introducedcouldincreasethestericsizeofcounterion(meanwhilethechargedensityofcounterionwasdecreased)andthustheadsorptiondensityofcounterionsontheair-waterinterfaceandmicellarsurfacewerebothdecreased.Finally,fromtheviewpointofouter-group-propertiesinsurfaceadsorptionlayer,theintroductionofhydroxylinto
10、counterionscouldpossiblymakemorewatermoleculespenetrateintothelayerandthusincreasetheycmcForthesystemsinvestigated,nosignificantruleswereobservedintheirfoamingabilities,whichcouldbeascribedtothecomplexityinthefactorsonfoaming(thecompactnessofmoleculararrangementinair-waterinterfaciallayer,viscosity,watercontentofthefilm,etc).Keywords:counter-ion;organicammoniumion;fluorocarbonsurfactant;foam;surfaceactivity;micellization