晶化介孔硅酸镁的制备及结构表征

发布时间：2018-04-15 18:31

本文选题：多孔材料 + 硅酸镁　；参考：《内蒙古大学》2015年硕士论文

【摘要】：硅酸盐材料因具有稳定性强,自然环保等优良特性而广泛的应用于吸附领域。特别是硅酸镁纳米材料可以作为一种高效的吸附剂用于对重金属离子、放射性同位素和有机污染物的吸附。作为吸附剂,高的比表面积和多孔结构可以提供更多的附着点和较大的吸附容量,是促进吸附剂和污染物之间相互作用的两个关键因素。因此,制备新型空心结构的硅酸镁材料成为当前科研领域的热点之一。与硅酸镁纳米空心球相比,介孔硅酸镁具有更好的水热稳定性,更短的运输路径,从而更适合作为吸附剂。然而,介孔硅酸镁材料的制备还很少被报道过。本论文中,以碳填充的SBA-15介孔氧化硅(C@SBA-15)为硬模板(母体模板)和硅源反应,通过牺牲辅助模板-水热法制备晶化介孔硅酸镁。在水热反应过程中,C@SBA-15孔道中的碳起到支撑孔壁的作用,由SiO：构成的母体模板孔壁与镁离子反应生成硅酸镁,成为新的外孔壁。最后通过高温煅烧去除起到支撑孔壁作用碳,生成品化介孔硅酸镁。利用PANalytical Empyrean X射线衍射仪通过Cu靶Kα辐射测试了晶化介孔硅酸镁晶体结构和介观结构。利用Hitachi S-4800型描电子显微镜和FEI TecnaiF20型透射电子显微镜分别表征了晶化介孔硅酸镁的形态、表面形貌与微观结构。利用ASAP 2020比表面积分析仪对材料进行N2吸-脱附等温测试。结果表明,本实验中通过水热合成法所制备的晶化介孔硅酸镁具有二维六方孔道结构,较大的比表面积和较好的水热稳定性。这些特征可以很好的提高吸附性能。以Pb2+和亚甲基蓝为研究对象,测试了新型晶化介孔硅酸镁材料的吸附性能。所合成的晶化介孔硅酸镁具有很好的吸附性能,可以广泛的用于污水中重金属离子的治理。上述研究表明,利用C@SBA-15和镁盐为原料合成新型介孔硅酸镁拥有较大的比表面积和再生特性,可以重复利用,对水体中污染物有很好的吸附特性。这一新的合成思路不仅为制备新型介孔硅酸盐材料提供了更多的可能性,而且可以更好的提高硅酸镁作为吸附剂的吸附效率。
[Abstract]:Silicate materials are widely used in adsorption field because of their excellent properties such as high stability and environmental protection.In particular, magnesium silicate nanomaterials can be used as an efficient adsorbent for the adsorption of heavy metal ions, radioactive isotopes and organic pollutants.As adsorbent, high specific surface area and porous structure can provide more attachment points and larger adsorption capacity, which are the two key factors to promote the interaction between adsorbent and pollutants.Therefore, the preparation of new hollow magnesium silicate materials has become one of the hot research fields.Compared with magnesium silicate nanospheres, the mesoporous magnesium silicate has better hydrothermal stability and shorter transport path, so it is more suitable as an adsorbent.However, the preparation of mesoporous magnesium silicate is rarely reported.In this thesis, crystalline mesoporous magnesium silicate was prepared by sacrificial auxiliary template-hydrothermal method using carbon-filled SBA-15 mesoporous silicon oxide (SBA-15 SBA-15) as hard template (matrix template) and silicon source reaction.During the hydrothermal reaction, the carbon in the channel of C @ SBA-15 acts as a support for the pore wall. The pore wall of the Sio: template reacts with the magnesium ion to form magnesium silicate, which becomes a new external pore wall.Finally, high temperature calcination is used to remove the supporting pore wall carbon, and the finished product is mesoporous magnesium silicate.The crystal structure and mesoscopic structure of crystalline mesoporous magnesium silicate were measured by PANalytical Empyrean X-ray diffractometer with K 伪 radiation from Cu target.The morphology, surface morphology and microstructure of crystalline mesoporous magnesium silicate were characterized by Hitachi S-4800 electron microscope and FEI TecnaiF20 transmission electron microscope, respectively.The N2 absorption-desorption isotherm was measured by ASAP 2020 surface area analyzer.The results show that the crystalline mesoporous magnesium silicate prepared by hydrothermal synthesis has two dimensional hexagonal pore structure, larger specific surface area and better hydrothermal stability.These characteristics can improve the adsorption performance.The adsorption properties of new crystalline mesoporous magnesium silicate materials were studied by Pb2 and methylene blue.The synthesized mesoporous magnesium silicate has good adsorption properties and can be widely used in the treatment of heavy metal ions in sewage.The results show that the new mesoporous magnesium silicate synthesized by using C@SBA-15 and magnesium salt as raw materials has large specific surface area and regeneration characteristics and can be reused and has good adsorption characteristics for pollutants in water.This new synthesis method not only provides more possibilities for the preparation of new mesoporous silicate materials, but also improves the adsorption efficiency of magnesium silicate as adsorbent.
【学位授予单位】：内蒙古大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ132.2;TB383.4

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