發(fā)布時(shí)間：2018-06-13 14:08

  本文選題：介孔硅材料 + 自組裝　； 參考：《上海師范大學(xué)》2017年碩士論文

【摘要】：介孔硅材料具有有序的孔道、可調(diào)的孔徑、可控的形貌結(jié)構(gòu),這些特點(diǎn)使其成為有效的催化劑載體;特別是構(gòu)建具有親水性的這類介孔硅材料作為催化劑,在催化反應(yīng)中具有重要的意義,這些具有親水性的硅材料作為催化劑不僅能提高在水介質(zhì)反應(yīng)體系的分散度、提高反應(yīng)速度,而且能夠重復(fù)使用。本論文第一部分通過點(diǎn)擊化學(xué)的策略,將手性有機(jī)小分子方酰胺類催化劑負(fù)載在親水性的介孔硅材料,制備了手性方酰胺負(fù)載型催化劑,并成功地應(yīng)用于水介質(zhì)的不對(duì)稱邁克爾加成反應(yīng)。汞離子(Hg~(2+))是有毒的重金屬元素之一。所以對(duì)汞離子的選擇性識(shí)別具有重要意義。在眾多的檢測(cè)重金屬離子的方法中,熒光探針因具有快速準(zhǔn)確、靈敏度高、專一性強(qiáng)的特點(diǎn)受到眾多研究者的關(guān)注。而擴(kuò)大熒光探針的適用范圍,簡(jiǎn)化探針的探測(cè)條件就是目前主要的優(yōu)化方向。(1)在本文第一部分中,利用聚乙二醇單甲基醚和超支化聚乙氧基硅烷發(fā)生酯交換反應(yīng),制備了親水性的聚合物前驅(qū)體;該聚合物前驅(qū)體與功能硅源3-巰丙基三乙氧基硅烷共聚合,組裝形成巰基功能化的介孔硅球;最后利用點(diǎn)擊反應(yīng)將有機(jī)小分子催化劑方酰胺嫁接到材料上,制備了具有囊泡球型結(jié)構(gòu)的手性方酰胺負(fù)載型催化劑。該催化劑對(duì)乙酰丙酮與硝基烯烴的不對(duì)稱邁克加成反應(yīng)表現(xiàn)出良好的催化活性(轉(zhuǎn)化率高達(dá)99%)和對(duì)映選擇性(手性值高達(dá)99%),同時(shí)該催化劑通過簡(jiǎn)單的離心回收并再利用8次,仍保持其較高的催化活性。(2)在本文第二部分中,設(shè)計(jì)、合成了一種基于氟硼吡咯為熒光團(tuán)和肼為活性基團(tuán)的汞離子熒光探針;該探針在水溶液中能在5分鐘內(nèi)完成對(duì)汞離子的檢測(cè)。研究發(fā)現(xiàn),該探針在水溶液中隨著汞離子濃度的增加,溶液紫外吸收明顯紅移,熒光強(qiáng)度大大增強(qiáng);即使是濃度非常低的汞離子(0.1μM)存在也可以使體系的熒光強(qiáng)度明顯增強(qiáng),說明了其具有非常好的靈敏度。另外通過選擇性實(shí)驗(yàn)表明該探針在同樣條件下對(duì)其它常見金屬離子沒有明顯響應(yīng),說明該探針具有很好的選擇性。
[Abstract]:Mesoporous silicon materials have ordered pore channels, adjustable pore size, controllable morphology and structure, which make them effective catalyst carriers, especially for the construction of hydrophilic mesoporous silicon materials as catalysts. These hydrophilic silicon materials as catalysts can not only increase the dispersion of the reaction system in water medium, but also can be reused. In the first part of this thesis, the chiral small molecular siloxane catalysts were prepared by clicking on the strategy of chemistry and supported on hydrophilic mesoporous silicon materials. It has been successfully applied to the asymmetric Michael addition reaction in water medium. Mercury ion (HG) is one of the toxic heavy metals. Therefore, the selective recognition of mercury ions is of great significance. Among the many methods for the detection of heavy metal ions, fluorescent probes have attracted much attention because of their rapid, accurate, high sensitivity and strong specificity. In the first part of this paper, the transesterification reaction between polyethylene glycol monomethyl ether and hyperbranched poly (ethoxy) silane is carried out. A hydrophilic polymer precursor was prepared, which was copolymerized with functional silicon source 3-mercapto triethoxy silane to form mercapto functionalized mesoporous silica spheres. Finally, the small organic catalyst was grafted onto the material by click-down reaction, and a chiral catalyst with vesicular spheroid structure was prepared. The catalyst showed good catalytic activity (conversion up to 99%) and enantioselectivity (chiral value as high as 99g) for asymmetric Michael addition reaction of acetylacetone with nitroolefins, and the catalyst was recovered by simple centrifugation and reused for 8 times. In the second part of this paper, we designed and synthesized a mercury fluorescence probe based on fluorboron pyrrole as fluorescence group and hydrazine as active group. The probe can detect mercury ions in aqueous solution within 5 minutes. It was found that with the increase of mercury ion concentration in aqueous solution, the UV absorption of the probe shifted significantly and the fluorescence intensity was greatly enhanced, and the fluorescence intensity of the system could be significantly enhanced by the presence of the very low concentration mercury ion (0.1 渭 M). It shows that it has very good sensitivity. In addition, the selective experiments show that the probe has no obvious response to other common metal ions under the same conditions, which indicates that the probe has a good selectivity.
【學(xué)位授予單位】：上海師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O643.36;O657.3

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本文編號(hào)：2014277