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ID:35124432
大小:1.42 MB
页数:46页
时间:2019-03-19
《探索镁铁层状双氢氧化物合成及其分散体系性能研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、天津大学硕士学位论文镁铁层状双氢氧化物合成及其分散体系性能研究姓名:张扬申请学位级别:硕士专业:化学工程指导教师:张明杰;袁梦欣2002.1.1摘要米用液相共沉淀法合成,Mg—Fe—LDHs纳米颗粒。考祭,粒子彤貌、化学组成、晶体结构、阴离子交换容量及原料配比的影哦发现Mg/Fe摩尔比在2:l一4:1范围内样品具有水滑石层状六方晶系结构,有良好的结晶度,颗粒为规则的六边形片状纳米颗粒:随Mg/Fe摩尔比从2:1增大到4:1,晶胞参数a从0.317nm减少到0.310nm,晶胞参数c从2.380hm增大
2、到2.412nm,层间距从0.793nm增大到。.8。4nm,阴离子交换容量o.52m。1/g,从增大到1.28m。l屈)一:∥⋯研究了Mg-Fe—LDHs分散体系的稳定性。e现随着pH值和Mg—FeLDHs吲含量的增加,体系悬浮性变差,AICl3、聚乙二醇、span20的加入对体系有保护作鼠,,研弼Mg—Fe—LDHs一钠质蒙脱土分散体系的流变学性质和触变性,讨论了lF电颗粒与负电颗粒之间的相互作用和缔合方式。f袅现颗粒之间可能通过边一面、边一边缔合形成絮凝块和形成三维网状结构。所研究的悬浮体的流型
3、为牛顿型流体和类似假塑性流体,调节Mg—Fe—I.DHs样品的加入量,可以改变体系的流型并且在‘定条件下增大了体系的动切力:MgFe—LDHs钠质蒙脱土分散体系具有独特的触变性,一定条件下体系可表现正触变性、负触变性、复合触变性,电解质的加入对体系的流性和触变性影响有限≯7一厂一~,【关键词】Mg—FeLDHs钠质蒙脱土分散体系悬浮率流变性触变性AbstractThenanoparticlesofmagnesiumferriclayereddoublehydroxides(Mg—Fe.LDHs)was
4、synthesizedbycoprecipitionmethod,andtheirshapechemicalcomposition,crystalstructure,anionexchangecapacityandtheeffectsofthegg/Feratiosinrawmaterialonthesepropertieswerestudiedbytransmissionelectronmicroscope,chemicalanalysisandXraydiffractionetc.Itwasfou
5、ndthattheMg-Fe—LDHsparticlesareplate-likenanoparticles,andtheirchemicalcompositionsarebasicallyconsistentwiththecompositionofrawmaterials.IntherangeofMg:Femolarratiointhechemicalcompositionofthesamplesfrom2:1to4:1.theparticlesizeofthesamplesincreasesfro
6、m37.9nmto61.2nm,andthelatticeconstant,a,ofthehexagonalcelldecreasesfrom0.317nmto0.310nmandthelatticeconstant,C,ofthehexagonalcellincreasesfrom2.380nmto2.412nm.andbasalspacingoftheMg·Fe—LDHsincreasesfrom0.793nmtoO.804nm.theanionexchangecapacityoftheMg-Fe
7、—LDHsncreasesfrom0.52mmol/gto1.82mmol馆ThestudyonthestabilityofMg·-Fe—·LDHsdispersionfoundthatitdecreaseswiththeincreaseofpHandthesolidcontent,andthatAICl3polyethaneol,span20canprotectitssuspensionTherheologicalandthixotropicbehaviorofMg·-Fe-·LDHs·-MTdis
8、persionwerestudied.Itisfoundthattheparticlesmayinteractbyedge—to—edgeandedge—to—faceandformthree-dimensionalstructure.AsthecontentofMg—Fe—LDHschanges,thedispersionsshowasNe、vtonorpseudoplasticsysteminrheologicalpropertyandpositiv
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