【作者】 刘健；

【导师】 郭亚军；

【作者基本信息】 哈尔滨工程大学 ， 应用化学， 2005， 硕士

【摘要】 桥键型有机-无机介孔材料,简称PMOs（Periodic Mesoporous Organosilicas）在1999年由三个小组相继独立报道合成。PMOs的成功合成将介孔材料由孔道化学拓展到了孔壁化学,骨架中的有机基团又使其具有独特的性能,因此有机-无机介孔材料成为目前介孔材料领域研究的一大热点。 本论文从双功能及多功能有机-无机介孔材料的合成出发,利用小角XRD、N₂吸附脱附、固体核磁、透射电镜（TEM）、紫外拉曼光谱、热重分析及红外光谱等多种表征技术对合成材料进行了表征,深入探索了双功能有机-无机介孔材料在酸催化、重金属离子吸附等方面的应用。合成了多功能有机-无机介孔材料,研究了骨架中有机基团的含量与材料性能的关系,并解决了在酸性条件下合成高度有序杂化材料的困难。 使用不同模板剂在酸性条件下合成了孔径在1.5～6nm,具有不同比表面积、孔容的巯基功能化有机-无机介孔材料,考察了其对重金属离子的吸附性能,吸附剂的最高硫含量为2.48mmol/g,对重金属离子都有非常好的吸附性能,对Hg²⁺的最大吸附量可达455mg/g;并且吸附量与材料的孔径及结构有密切的关系;同时开发了一种多功能吸附剂,可吸附废水中Hg²⁺,Cd²⁺,Zn²⁺,Cu²⁺及Cr³⁺等多种重金属离子。 与传统的沸石分子筛相比,介孔材料的酸性仍需提高以满足生产实际的需要,我们使用双氧水原位氧化合成了骨架中含有—CH₂CH₂—或—Ph—的磺酸基功能化有机-无机介孔材料,材料的最高酸量可达1.72mmol/g,并以缩聚、酯化等反应作为模型反应研究了合成材料的催化性能,材料在各催化反应中都显示出良好的催化性能,并且骨架中有机基团的种类对其催化活性及选择性有很大影响。 值得一提的是首次使用三种硅酯作为硅源前体一步共聚合成了多功能的有机-无机介孔材料,考察了骨架中有机基团对所合成材料性能的影响,证明了骨架中有机基团是影响材料水热稳定性的关键因素,使用多个模型反应考察了材料的催化活性,发现有机基团在骨架中的含量与其催化性能也有一定的关系。更多还原

【Abstract】 Organic bridged hybrid mesoporous materials named periodic mesoporous organosilicas （PMOs） were reported by three groups independently in 1999. These materials contain the organic groups as an integral part of the inorganic-oxide framework and the inorganic and organic moieties are covalently linked to each other. Hence, the "chemistry of the void space" explored by the classical MCM-41-type materials was extended to the "chemistry of the walls". This novel route offers materials with some important features that cannot be obtained by other approaches.The current contribution concerns the synthesis, characterization and application of bi-functionalized and mutil-functionalized organic-inorganic hybrid mesoporous silicas. The synthesized materials were further characterized by XRD, nitrogen sorption analysis, ²⁹Si MAS NMR and ¹³C CP MAS NMR technique, thermogravimetric analysis, UV-Raman and FT-IR spectroscopy etc. The applications in catalysis and adsorption were studied in detail. Finally, we synthesized mutil-functional periodic mesoporous organosilicas successfully. The effect of organic group was studied.Using nonionic oligomeric and triblock copolymers Brij-76 and P123 as surfactant for the synthesis of thiol functionalized ethane-silicas, the materials have different BET surface area and pore volume and the diameter from 1.5 to 6 ran. The maximum content of the attached thiol group in the mesoporous framework is 2.48 mmol/g. The ordered mesoporous materials are efficient heavy metal ions adsorbents, the maxium adsorption amount of Hg²⁺ is 455 mg/g. The large and uniform pore structures are one of the most important factors for propylthiol functionalized mesporous materials to be efficient heavy metal ions adsorbent. The mutil-functional adsorbents are efficient to remove various kinds of heavy metal ions such as Hg²⁺, Cd²⁺, Zn²⁺, Cu²⁺, and Cr³⁺ from wastewater.Compared to zeolites, the acidity of the mesoporous is relatively low which greatly limited their applications. We synthesis of sulfonic functionalized periodic mesoporous organosilicas by H₂O₂ （30 wt %） in-situ oxidized -SH to -SO₃Hduring the condensation process. The highest acid exchange capacity （acid-base titration methods） could achieved was 1.72 H+ mmol/g. The catalytic properties of all materials were investigated by condensation and esterification reactions. All of the materials are efficient catalysts for the reactions. Results demonstrated that the organic moieties bridged in the framework played an important role on the catalytic activity and selectivity of the materials.It is noteworthy that multi-functional periodic mesoporous organosilicas have been successfully synthesized by the one-step condensation of three silica precursors in acidic medium for the first time. The role of the bridging ethane moieties on the hydrothermal stability of the mesoporous materials was also investigated. The catalytic activities of the materials were investigated in several reactions,, and the amounts of the ethane groups incorporated have great effect on their catalytic activity and hydrothermal stability.更多还原