【作者】 汪尚兵；

【导师】 汤德平； 李湘祁；

【作者基本信息】 福州大学 ， 材料学， 2004， 硕士

【摘要】 硅基介孔材料M41S（MCM-4l和MCM一48）具有规则的孔道排列、窄的孔径分布以及可调的孔径、高的比表面积和大的吸附容量等优异性能，使得它在诸多领域有着广阔的应用前景。本论文采用传统的水热合成方法制备了M4lS，分析了不同因素对M41S制备的影响，同时也研究了Ti⁴⁺、B³⁺、A1³⁺等离子的搀杂给M41S结构性能带来的变化。 本文系统研究了反应物配比（CTAB／TEOS，NaOH／TEOS，H₂0／TEOS）、水热参数（温度，时间）等对M4lS合成的影响，得出：CTAB／TEOS与NaOH／TEOS的值是决定M41S类型的两个关键因素。NaOH／TEOS较低时（≤O．3），体系只适合于合成MCM-41，而不论CTAB／TEOS的值多大，也合成不了MCM-48；NaOH/TEOS值较高时（≥0．48），只要CTAB／TEOS达到一定值（0．2以上），就能合成MCM-48。另外还发现比较适合于MCM-41合成的条件是：CTAB／TEOS为O．1、Na0H／TEOS在0．24-0．36、水热温度范围在90℃-120℃之间、水热时间48h；而CTAB／TEOS在（0．2，0．4）之间、NaOH／TEOS为0．48、水热温度在110℃、H₂O／TEOS在（64．6，101．9）之间，则比较有利于MCM-48的合成。 笔者还研究了碱介质种类（NH₃．H₂O，EDA、NaOH／TEA）对：MCM-4l合成的影响，弱碱介质（NH,H₂O，EDA）中室温合成的原MCM-41比强碱介质（NaOH）中得到的样品有着更好的热稳定性，水热处理可以改善弱碱介质中得到样品骨架的有序性、提高其致密度。氨水介质中，NH₂／TEOS值在（8，25）之间越小，越有利于MCM-41的室温合成；室温条件下EDA介质中得到样品的烧成收缩量与EDA／TEOS的值成正比;与NaOH介质相比，混合介质（Na0H／三乙醇胺）中水热合成的样品具有较厚的孔壁，有着更好的水热稳定性，但同时孔径相应较小。 B³⁺引入会改善MCM-4l骨架的有序性，但存在于二氧化硅骨架中B³⁺不稳定、极易水解，从而会导致MCM-41骨架的坍塌。Ti⁴⁺的引入会破坏M4lS骨架的有序性，FT-IR图谱表明，Ti⁴⁺的引入，会导致波数在1220cm^-1、960cm^-1、777cm^-1等附近处吸附峰强度的变化，特别是777cm^-1。附近的吸收峰强度的显著变化被看作Ti⁴⁺进入到M41S骨架中的标志。A1³⁺的引入会给MCM-48骨架的有序性造成明显的破坏，FT-IR图谱显示，Al³⁺的引入会导致波数在1220cm^-1、960cm^-1、730cm^-1等附近吸收峰强度的变化。更多还原

【Abstract】 Silica-based mesoporous material M41S possesses a series of excellent qualities such as regular arrangement of channels, narrow pore size distribution and tailorable pore size, high specific surface area, huge adsorptive volume and so on. These make the materials have wide application prospect in many fields. M41S have been synthesized in the hydrothermal treatment and the influence factors of on the synthesis of M41S have been discussed in the paper. Meanwhile, we also explore the change of structure and quality resulted from the incorporation of ions such as Ti4+,B3+, Al3+ and so on.We studied systematically the effect of the ratios of agents (CTAB/TEOS, NaOH/TEOS,H2O), hydrotherm parameters (temperature and time) and so on in the preparation of M41S, and concluded: the ratios of CTAB/TEOS and NaOH/TEOS are the two key factors in determining the sort of M41S. The system with a low ratio of NaOH/TEOS(≤0.3) is only fit for the synthesis of MCM-41, but not for MCM-48, no matter what the ratio of CTAB/TEOS is. MCM-48 can be synthesized on condition that the ratio of CTAB/TEOS reaches to a certain value(≥0.2) in the system with a high ratio of NaOH/TEOS(≥0.48). The conditions favorable to the synthesis of MCM-41 are the ratio of CTAB/TEOS 0.1, NaOH/TEOS 0.24-0.36, hydrothermal temperature from 90oC-120oC, hydrothermal time 48h. However, the ratio of CTAB/TEOS 0.2-0.4, NaOH/TEOS at 0.48, H2O/TEOS 64.6-101.9 and hydrothermal temperature at 110oC are advantageous to the synthesis of MCM-48.We discuss the influence of basic media (NH3.H2O, EDA, NaOH/TEOS) on the synthesis of MCM-41. As-synthesied samples obtained in weak basic media (NH3.H2O, EDA) possess more thermal stability than in the strong one(NaOH) at room temperature. And hydrothermal treatment can improve the order and density of the framework of samples synthesized in weak basic media. at room temperature. The smaller the ratio of NH3/TEOS is more helpful for the synthesis of samples. The contraction from calcination of samples obtained in EDA medium is proporational to the ratio of EDA/TEOS at room temperature. The samples obtained in mixed basic media (NaOH/TEA ) have thicker wall and more thermal stability than in NaOH medium, but pore size is smaller correspondingly.<WP=4>The incorporation of B3+ can improve the order of the framework of MCM-41, but B3+ in SiO2 matrix is unstable and easy to be hydrolyzed, which eventually results in the collapse of framework. The incorporation of Ti4+ can damage the order of the framework of M41S. It results in changes of the intensity of adsorptive peaks at about 1220cm-1, 960cm-1, 777cm-1 in the spectra of FT-IR. Especially, intensity change of peak at about 777cm-1 has been considered as the indication of Ti4+ incorporated into the matrix of M41S. Incorporation of Al3+ can damage the order of the framework of MCM-48 obviously, which is indicated by change of the intensity at about 1220cm-1, 960cm-1,730cm-1 in the spectra of FT-IR.更多还原