【作者】 阚春；

【导师】 汪信； 刘孝恒；

【作者基本信息】 南京理工大学 ， 材料学， 2007， 博士

【摘要】 自组装是指分子及纳米颗粒等结构单元在平衡条件下，通过非共价键作用自发地缔结成热力学上稳定、结构上确定、性能上特殊的聚集体的过程。它在纳米材料研究中越来越引起人们的重视。本文以阴离子表面活性剂为模板，金属醇盐为原料，利用自组装的方法制备了具有有序结构的空气-水界面薄膜。采用了X射线衍射、红外光谱、拉曼光谱、核磁共振、热重-差热分析、扫描电子显微镜、透射电子显微镜、能谱等一系列分析手段，对这种薄膜样品的组成、结构、性质、机理等诸多方面进行了研究。全文主要研究内容如下：使用十二烷基磺酸钠和十二烷基苯磺酸钠为模板，在明胶的稳定作用下，以自组装方法制备了以多环纳米盘为组成颗粒的ZrO₂基空气-水界面薄膜，其环间距约为3.3nm。使用核磁共振对明胶与表面活性剂间的相互作用进行了研究，提出了成环机理，并利用透射电子显微镜观察的结果对机理进行了验证。实验中还发现了在体系中同时存在支链反应，并对纳米盘生成的动力学过程进行了讨论。研究了ZrO₂多环纳米盘的热性能，对其相转变过程进行了深入探讨。同时，还以十二烷基磺酸钠、十二烷基苯磺酸和β萘磺酸钠3种表面活性剂为模板在无明胶的条件下制备了ZrO₂基自组装薄膜。使用表面活性剂十二烷基磺酸钠、十二烷基苯磺酸钠、十二烷基苯磺酸和十二烷基硫酸钠为模板在空气．水界面制备了TiO₂基自组装薄膜。实验结果表明，由不同表面活性剂制备的薄膜结构和相应的d值也各不相同。以十二烷基硫酸钠制备的自组装薄膜为例，讨论了表面活性剂对层间距影响。发现自组装层结构的模板是表面活性剂双分子结构，而双分子结构作为模板时会发生倾斜，自组装结构的层间距由表面活性剂分子长度、双分子结构的重叠部分的长度和倾斜角三者共同决定。考察了十二烷基磺酸钠模板在TiO₂基自组装薄膜中的稳定性，硝酸、硫酸、磷酸、醋酸对自组装膜的影响，以及不同分子量的聚乙二醇和水溶性淀粉对自组装膜的影响。使用表面活性剂十二烷基磺酸钠为模板制备了TiO₂／ZrO₂、TiO₂／SiO₂和ZrO₂／SiO₂一系列二元氧化物自组装薄膜。X射线衍射证明薄膜中均有层状结构存在，但层结构在煅烧后都发生了坍塌。透射电子显微镜观察发现：TiO₂／ZrO₂薄膜主要由棒状纳米颗粒组成，颗粒上可以观察到明显的层状结构，且层状结构与纳米棒的长度方向相垂直；ZrO₂／SiO₂薄膜主要由叶片状纳米颗粒组成。使用阴离子表面活性剂在强碱性环境中自组装制备了ZnO基空气-水界面膜。X射线衍射和透射电子显微镜观察证实了层状结构和六方相结构的存在。提出了这种薄膜的形成机理：在薄膜自组装过程中，Na⁺离子充当了无机前驱体和表面活性剂模板间的桥梁；而体系的pH值则影响了表面活性剂模板的聚集状态。使用表面活性剂十二烷基磺酸钠为模板剂制备了Al₂O₃基和SiO₂基空气-水界面自组装薄膜。X射线衍射和透射电子显微镜证实Al₂O₃基薄膜中有层状结构存在，相应的d值为3.2mm；而SiO₂基薄膜中只有介孔结构存在，相应的d值为2.6m。更多还原

【Abstract】 Fabrication of materials with various nanoarchitectures is of great scientific andtechnological importance, and self-assembly technique is an important approach to thedevelopment of nanostructured materials. The preparation of inorganic material-basedfilm using self-assembly technique has attracted intense research interest over recentyears. In this paper, a series of air-water interfacial films with ordered structure aretemplated by anion surfactants with organic metallic alkoxide precursors. X-raydiffraction, Fourier-Transform Infrared Spectra, Raman Spectra, Nuclear MagneticResonance （NMR）, Thermal Gravity and Differential Thermal Analysis, Scaning ElectronMicroscope, Transmission Electron Microscope and Energy Dispersive Spectra are use tocharacterize the self-assembled films. The formation mechanism of the films is alsoinvestigated.Zirconia films composed of multiring nanodisks are self-assembled by sodium dodecylsulfonate and sodium dodecyl benzene sulfonate with gelatin as stabilizer. The interactionbetween surfactant headgroups （dimeric molecular bar） and zirconia planes is proved tobe the key to form the structure by TEM, HRTEM and NMR. Especially the formationalmechanism of the primary centre of the disk is also investigated in detail by TEM. Thethermal property of the zirconia nanodisks is also investigated.Three anionic surfactants （H⁺A^-, Na⁺A）, sodium dodecyl sulfate, sodium dodecylsulfonate, sodium dodecyl benzene sulfonate and dodecyl benzene sulfonate acid, havebeen employed to template the self-assembly of titania interracial films withorganometallic compounds as precursors. All obtained films display well-orderedstructures. For the films prepared with sodium dodecyl sulfate, as a typical example, therelations between the d spacing of the lamellar structure, the critical chain length ofsurfactant molecule as well a the included angle of tilted surfactant molecule werediscussed quantitatively. By the way, further investigations have been focused on thestabilities of the surfactant template in the titania interracial films.TiO₂/ZrO₂, TiO₂/SiO₂ and ZrO₂/SiO₂ binary oxides films are self-assembled withsodium dodecyl sulfonate as template. All the films are composed of lamellar particleswith a d spacing of 3.2 nm. The particles composing TiO₂/ZrO₂ films are nano rods withthe lamellas which are perpendicular to the lengthwise position of the rods. And the particles composing ZrO₂/SiO₂ film are leaf-like slices with lamellar structure. But thelamellar structure in the films collapse after calcinations.ZnO film is self-assembled with anion surfactant （sodium dodecyl sulfonate） inalkaline solution. Lamellar structure and hexagonal structure are found respectively inZnO film prepared in the solution with different pH. It is surmised that counterion Na+ion get involved as charge compensating species and a joint of surfactant and mineralspecies.Moreover, Al₂O₃ and SiO₂ film is self-assembled with anion surfactant （sodiumdodecyl sulfonate） as template. Lamellar structure is found in Al₂O₃ film, whilemesoporous structure is observed in SiO₂ film.更多还原