镧(Ⅲ)对SBA-15分子筛改性研究

借助水热法，利用三嵌段共聚物聚(1，2—亚乙基二醇)—嵌段—聚(丙二醇)—嵌段—聚(1，2—亚乙基二醇)为模板剂，正硅酸四乙酯为硅源，强酸性条件下制备了分子筛SBA—15．分别以水及水 乙醇为介质采用LaCl3溶液与煅烧的主体材料SBA—15分子筛固—液相交换法，制备了La—(SBA—15)复合材料．利用化学分析、粉末XRD、N2吸附技术、IR评价了制备方法的有效性及对SBA—15分子筛孔结构的影响．结果表明，镧已并入SBA—15分子筛中，SBA—15内表面上的硅羟基团是镧进入的主要位置，部分客体在分子筛孔道内．制得的材料La—(SBA—15)保持高度有序的介孔二维六角结构，不改变载体SBA—15的介SLSL道结构．此外，考察了La—(SBA—15)产物的发光现象。

Modification for SBA-15 Molecular Sieve by Lanthanum(III)

SBA-15 molecular sieve was prepared under a strong acidity condition by using triblock copolymer, poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) as the template and tetraethyl orthosilicate as the silica source by means of a hydrothermal method. La-(SBA-15) composite materials were prepared by a solid-liquid exchange method using the calcinedhost material SBA-15 molecular sieve and lanthanum chloride in water and water+alcohol media, respectively. By mean of chemical analysis, powder X-ray diffraction, nitrogen adsorption-desorption technique and infrared spectroscopy, the validity of the preparative method and the effect of it on the pore structure of SBA-15 molecular sieve were evaluated. In addition, the luminescence phenomena of La-(SBA-15) product were observed. The results show that lanthanum has been incorporated into SBA-15 molecular sieve. The silanol groups on the internal wall surfaces are the major sites for lanthanum incorporation. The part of the guest is in the channels of the molecular sieve. The prepared materials La-(SBA-15) keep the highly ordered mesoporous two-dimensional hexagonal structure and do not change the mesoporous channel structure of the support SBA-15.