Organic templates of as-synthesized siliceous,MCM-41 and SBA-15 can be effectively removed by oxidation treatment.The highly ordered mesostructures and surface properties of inorganic frameworks were retained after the template being removed.MCM-41 and SBA-15 obtained after oxidation treatment showed larger pores and richer silanol groups compared with those obtained by conventional calcinations at 550 ℃ in air.The removing ratios of templates of MCM-41 and SBA-15 were respectively 88% and 98%.
Silver nanoparticles were prepared in the channels of mesoporous silica SBA-15 through silver mirror reaction.The results of X-ray diffraction(XRD) and transmission electron microscopy(TEM) reveal that Ag nanoparticles with uniform size about 2-3 nm were dispersed inside the channels of mesoporous SBA-15.UV-Vis absorption spectra indicate the quantum size effect of the Ag nanoparticles.Bacteriological tests were performed in Luria-Bertani(LB) medium on solid agar plates and in liquid systems supplemented with different concentrations of Ag/SBA-15.This nanocomposite was shown to be an effective bactericide against Staphylococcus.
The title compound [Zn3（BTC）2（H2O）3]n（BTC=1,3,5-benzenetricarboxylic acid） was synthesized under mild conditions and its crystal structure was determined by single crystal X-ray diffraction. The compound crystallizes in the cubic system and belongs to space group Fm-3m with a=2.662 6（3） nm ,V=18.877（4） nm 3,Z=16,Dc=1.51 g/cm 3,Mr=664.4,μ=0.198 mm -1 , F（000）=852 ,R=0.062 5,wR=0.129 4. Its structure reveals that the title polymer is composed of dimeric zinc tetracarboxylate units,with a short Zn-Zn internuclear separation of 0.295 0（4） nm. The coordination of BTC ligands with Zn ions forms a 3D infinite framework with about 1.117 4 nm×1.327 4 nm pores along the [001],[100] and [010] direction. [WT5HZ]
金属有机骨架(Metal organic framework,MOF)配位聚合物作为一类重要的多孔材料具有诸多独特的性能.新型MOF材料的结构表征与确定一直是该研究领域的关键性研究问题.由于单晶X-射线衍射等结构测定方法对晶体尺寸有一定限制,小尺寸MOF新材料的晶体结构确定一直是亟待解决的科学难题.透射电子显微分析方法(Transmission electron microscopy,TEM)作为纳米尺寸晶体材料最有力的结构表征手段之一,已经被逐渐应用于MOF新材料领域,展现出了巨大的应用潜力.本文以几个国内外有代表性的工作为例,浅析TEM在MOF材料领域的发展现状.
