【作者】 滕敏敏；

【导师】 郝京诚；

【作者基本信息】 山东大学 ， 物理化学， 2008， 硕士

【摘要】 表面活性剂在水溶液中的浓度高于临界胶束浓度时，可以发生自聚集，形成多种形态的聚集体，如胶束、囊泡、微乳液、溶致液晶等。其中，囊泡相由于其在生命科学和材料科学等方面的广泛应用而成为研究的热点。近年来，人们将氢键、静电作用和金属配位作用作为水溶液中形成囊泡相的三种典型的非共价键相互作用力。本文对二价金属离子(Ca²⁺和Mg²⁺)为反离子的阴离子表面活性剂与具有配位作用的十四烷基二甲基氧化胺(C₁₄DMAO)的表面活性剂复配体系进行了研究，具体内容如下：1将Ca²⁺和Mg²⁺为反离子的阴离子表面活性剂十四烷基酰胺甲基硫酸钙[(CH₃（CH₂）₁₃NHCOCH₂OSO₃)₂Ca]和十二烷基硫酸镁[Mg（DS）₂]分别与具有配位作用的十四烷基二甲基氧化胺(C₁₄DMAO)复配，相行为研究表明：在一定的配比范围内观察到囊泡相的存在，该囊泡相的形成是由于Mg²⁺、Ca²⁺与C₁₄DMAO的头基紧密结合形成配位键，金属离子的配位作用是此体系形成囊泡相的驱动力，此结论可由十四烷基酰胺甲基硫酸钠[CH₃（CH₂）₁₃NHCOCH₂OSO₃Na]和十二烷基硫酸钠（SDS）分别与C₁₄DMAO复配，只得到粘稠的胶束相得到验证。囊泡相的结构与性质通过偏光显微镜、负染色透射电镜及流变仪等进行了表征。2利用所得到的囊泡相作为聚集体模板反应器制备了草酸钙（CaC₂O₄）晶体和片状氧化镁（MgO）。草酸二甲酯作为沉淀剂在水溶液可以水解得到草酸和甲醇，草酸与溶液中的Ca²⁺反应生成草酸钙沉淀，发生如下反应：Ca²⁺+H₂C₂O₄→CaC₂O₄↓+2H⁺。反应产生的H⁺与C₁₄DMAO结合，C₁₄DMAO被质子化为阳离子C₁₄DMAOH⁺，即C₁₄DMAO+H⁺→C₁₄DMAOH⁺。最终，溶液中的C₁₄DMAOH⁺与CH₃(CH₁₂)₁₃NHCOCH₂SO₄^-构筑了一个新的阴／阳离子表面活性剂混合体系；在Mg²⁺诱导形成的囊泡相中反应制得Mg（OH）₂，Mg（OH）₂经高温煅烧得到纳米级片状MgO。CaC₂O₄和MgO晶体的性质经X射线衍射（XRD）、扫描电镜（SEM）等手段进行表征。试验表明囊泡相的存在可以抑制颗粒间的聚集，改变晶体的生长习惯。更多还原

【Abstract】 Above the critical micelle concentration （cmc） , surfactants can form various self-assembly aggregates, such as micelles, vesicles, micro-emulsions and liquid crystals etc. Vesicle phase, as one of them, has been a subject of fascinating research due to their potential applications in various fields such as colloid chemistry, bionics and material science. In recent years, three typical noncovalent interactions to form vesicles: hydrogen bonds, metal ion coordination and electrostatic attraction have been used as noncovalent attractive intermolecular interactions to control the self-assemblies of surfactants. Several surfactant systems in aqueous solutions are studied in this paper and the results are summarized as following:1 Ca²⁺/Mg²⁺-ligand coordinated vesicle phase was prepared in the mixed aqueous solution of tetradecyldimethylamine oxide (C₁₄DMAO) with calcium tetradecylamidomethylsulfate [(CH₃（CH₂）₁₃NHCOCH₂SO₄)₂Ca] and magnesium dodecylsulfate[Mg（DS）₂], respectively. At the right mixing ratios, Ca²⁺/Mg²⁺-ligand coordination results in the formation of molecular bilayers. The structures of the birefringent solutions were determined by transmission electron microscopy （TEM） images and rheological measurements, demonstrating the samples consist of vesicles.2 Ca²⁺-ligand complex vesicle phase was used as microreactors to prepare CaC₂O₄ crystals (Ca²⁺ + H₂C₂O₄→CaC₂O₄↓+ 2H⁺). Dimethyl oxalate as a precursor, which can hydrolyze to oxalic acid and ethanol. should precipitate Ca²⁺ ions coordinated in the bilayer films to produce CaC₂O₄ crystals. After removal of CaC₂O₄ particles, a new cationic/anionic （cataniomc） vesicle-phase solution was constructed from cationic C₁₄DMAOH⁺ (C₁₄DMAO + H⁺→C₁₄DMAOH⁺) and anionic CH₃(CH₁₂)₁₃NHCOCH₂SO₄^-. Magnesium oxide nanoplates was synthesized using ammonia hydroxide as precipitator in the presence of Mg²⁺-induced vesicle phase. The morphologies and structures of the synthesized crystals have been characterized by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. It is believed that the vesicle phase as microreactors play an important role in controlling the morphologies of crystals.更多还原