介孔二氧化硅纳米颗粒的制备、改性及其应用研究

发布时间：2018-08-10 22:25

【摘要】：近年来,介孔二氧化硅纳米材料(MSNs)已经吸引了广泛的注意,由于其在催化、吸附分离和载药等领域存在巨大的潜在利用价值。大量的研究工作已经表明,介孔二氧化硅自身复杂的框架结构、内部的孔道结构以及外在形貌等都对其实际应用具有重要影响。不仅如此,许多功能团也被嫁接到介孔硅上以拓展其应用,这是因为功能化介孔硅能很好地实现有机体功能性与无机体的大比表面积和高稳定性相结合的可能。本论文中,我们提出了一些新的思路来合成介孔二氧化硅材料,并且成功制备出了一系列小粒径的介孔二氧化硅及其功能化产物,此外还将它们运用到了实际应用上。主要研究内容如下：1.以正硅酸乙酯(TEOS)为硅源和十六烷基三甲基溴化铵(CTAB)为表面活性剂,利用8种不同的小分子有机胺(SOAs；四羟乙基乙二胺、四羟丙基乙二胺、四乙基乙二胺和羟乙基六氢均三嗪)和含氮杂环化合物(NCHCs; 1,8-双二甲氨基萘、咪唑、哌嗪和吡啶基哌嗪)为催化剂合成了一系列小粒径单分散的二氧化硅颗粒；并考察以四羟乙基乙二胺(THEEDA)为催化剂所合成的介孔材料的分散性和增透／防雾应用效果,以及改变THEEDA/TEOS对所合成材料结构和形貌的影响。实验结果表明：我们不仅首次利用这8种催化剂成功合成了一系列小粒径单分散的二氧化硅纳米颗粒,而且通过选取不同的SOAs和NCHCs还能有效地调节单分散介孔硅颗粒的粒径、孔径以及比表面积等性质。同时,对于以THEEDA为催化剂所合成介孔材料,通过改变THEEDA/TEOS的摩尔比例,也能很好地调控其颗粒的粒径、孔径和比表面积的增加,以及大幅度提高材料孔道的有序化程度。此外,研究结果也进一步表明以THEEDA为催化剂合成的介孔材料所制备的溶胶具有良好的分散性、溶胶稳定性以及增透／防雾的应用效果。2.针对以THEEDA为催化剂制备的介孔二氧化硅纳米颗粒进行巯基功能化处理,巯基改性后的介孔硅颗粒在处理Au3+和Hg2+重金属离子时显示其良好的吸附性能。通过场发射扫描电镜(FE-SEM)、透射电镜(TEM)、动态光散射仪(DLS)、N2吸附脱附和X射线衍射仪(XRD)等一系列仪器对其样品进行了进一步表征,测试结果表明：这些颗粒都保持了原有的球形结构、均一的粒径(约30-40 nm)、大的比表面积(约500 m2/g)口孔容(16 cm3g-1)以及狭小的孔径分布(3 nm)。功能化后的纳米颗粒对重金属离子Au3+和Hg2+有良好的吸附性能,而且在重金属离子Au3+的检测和回收方面有潜在的应用价值。3.在阳离子表面活性剂CTAB作模板剂的碱性条件下,通过共缩聚TEOS和具有疏水烷烃链的有机烷氧基硅烷((RSi(OR') 3, R=C3H7, C8H17, C12H25)的方法,有机官能团被成功的嫁接到二氧化硅颗粒表面。通过场发射扫描电镜、透射电镜、X射线衍射仪、傅里叶变换红外光谱仪和N2吸附脱附和等一系列仪器对其样品进行表征,实验表征结果表明：这些球形的功能化介孔二氧化硅颗粒都具有有序的2D六方结构以及大比表面积(1000 m2g)、大孔容(1.2 cm3g-1)、较窄的孔径分布(2.7 nm)和均一的小粒径(约110 nm)。而且,通过增加DTES用量和延长有机硅烷烷基链的长度,可以有效地调节介孔二氧化硅颗粒的粒径及孔道结构。最后,通过浸渍提拉法,利用DTES-50颗粒溶胶(0.05g/25 ml乙醇)制备出的玻璃片涂层显现出良好的超亲水／防雾性能。
[Abstract]:In recent years, mesoporous silica nanomaterials (MSNs) have attracted extensive attention due to their potential applications in catalysis, adsorption separation and drug loading. A large number of studies have shown that mesoporous silica has its own complex framework structure, internal pore structure and external morphology. In addition, many functional groups have been grafted onto mesoporous silicon to expand their applications. This is because functionalized mesoporous silicon can achieve a good combination of organic functionality with large specific surface area and high stability of inorganic materials. In this paper, we propose some new ideas to synthesize mesoporous dioxide. The main research contents are as follows: 1. Using tetraethyl orthosilicate (TEOS) as silicon source and Cetyltrimethylammonium Bromide (CTAB) as surfactant, eight kinds of small molecular organic amines (small molecular organic amines) were used. A series of small size monodisperse silica particles were synthesized by using SOAs, tetrahydroethyl ethylenediamine, tetrahydropropyl ethylenediamine, tetraethyl ethylenediamine and hydroxyethyl hexahydrotriazine, and nitrogen heterocyclic compounds (NCHCs; 1,8-dimethylnaphthalene, imidazole, piperazine and pyridylpiperazine) as catalysts. The dispersion, antifogging and antifogging properties of mesoporous materials synthesized by the catalysts and the effect of changing THEEDA/TEOS on the structure and morphology of the materials were investigated. The experimental results show that we have successfully synthesized a series of small size monodisperse silica nanoparticles for the first time by using these catalysts, and by selecting non-disperse particles. The same SOAs and NCHCs can also effectively adjust the particle size, pore size and specific surface area of monodisperse mesoporous silicon particles. Meanwhile, for mesoporous materials synthesized with THEEDA as catalyst, by changing the molar ratio of THEEDA / TEOS, the particle size, pore size and specific surface area can be well controlled, and the material can be greatly improved. In addition, the results also show that the mesoporous materials synthesized by THEEDA have good dispersibility, stability and antifogging effect. 2. The sulfhydryl functionalization of mesoporous silica nanoparticles prepared by THEEDA as catalyst. Sulfhydryl modified mesoporous silicon particles showed good adsorption properties when treated with Au3+ and Hg2+ heavy metal ions. The samples were further characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), dynamic light scattering spectroscopy (DLS), N2 adsorption desorption and X-ray diffraction (XRD). The results showed that: 1. These particles retain the original spherical structure, with uniform particle size (about 30-40 nm), large specific surface area (about 500 m2/g) pore volume (16 cm3 g-1) and narrow pore size distribution (3 nm). The functionalized nanoparticles have good adsorption properties for heavy metal ions Au3+ and Hg2 +, and have potential for the detection and recovery of heavy metal ions Au3 +. Application Value. 3. In alkaline condition of cationic surfactant CTAB as template, organic functional groups were successfully grafted onto the surface of silica particles by copolycondensation of TEOS and organic alkoxysilane with hydrophobic alkane chain ((RSi (OR') 3, R = C3H7, C8H17, C12H25). The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption and desorption. The experimental results show that these spherical functionalized mesoporous silica particles have ordered 2D hexagonal structure, large specific surface area (1000 m2g), large pore volume (1.2 cm 3g-1), narrow pore size distribution (2.7 nm) and narrow pore size distribution (2.7 nm). Moreover, the size and pore structure of mesoporous silica particles can be effectively adjusted by increasing the amount of DTES and lengthening the alkyl chain length of organosilane. Finally, the glass sheet coating prepared by dipping and pulling method with DTES-50 granular sol (0.05g/25 ml ethanol) shows good superhydrophilicity/superhydrophilicity. Anti fog performance.
【学位授予单位】：河南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.2

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