介孔硅表面离子印迹聚合物的制备及其选择性分离重金属离子的研究
发布时间：2018-09-18 11:12
【摘要】：介孔材料由于比表面积大、传质快、吸附容量高等特点,现已被广泛应用于吸附领域,特别是硅基介孔材料,因其表面负载丰富的硅醇基,为进一步功能化提供了便利。目前,基于介孔硅表面制备对目标物具有靶向识别能力的表面印迹聚合物已成为当下吸附领域研究的热点。近几年,大量的重金属污染物随工业废水已被排放到环境中,对人体和生物体构成了严重威胁。开发新型具有吸附容量大、选择性强、再生性能优良等特性的表面离子印迹聚合物,来去除水体中的重金属污染物已迫在眉睫。本课题分别以不同结构的介孔硅作为基质材料,选择Pb(II)、Cr(VI)、Cu(II)为模板离子,合成了三种新型表面离子印迹聚合物,并探讨了其在重金属离子选择性分离中的应用,其研究内容和实验所得结果如下:(1)分别以3-(γ-氨基乙氨基)-丙基-三甲氧基硅烷(AAPTS)和3-氨丙基三乙氧基硅烷(APTES)作为功能单体,制备了两种对铅离子具有高效选择性的介孔硅吸附剂Pb(II)-IMS-NN和Pb(II)-IMS-N。制备的吸附剂通过傅里叶转换红外光谱(FT-IR)、X射线光电能谱仪(XPS)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、热重分析(TGA)、N2吸附-脱附实验等表征分析。数据表明Pb(II)-IMS具有高度有序的介孔结构和良好的热稳定性。在一系列的静态和动态吸附实验中,Pb(II)-IMS-NN比Pb(II)-IMS-N呈现更高的饱和吸附容量,并随后将其应用于一系列不同条件下的固定床吸附实验中。实验结果显示,固定床穿透时间随着床高的增加而增加,但随着流速和流入Pb(II)浓度的增加而降低,而且Thomas模型比Adams-Bohart模型更加适合描述动态吸附实验数据。此外,Pb(II)-IMS-NN比Pb(II)-IMS-N对Pb(II)呈现更优异的选择性和更高的亲和力。(2)以γ-甲基丙烯酰氧基丙基三甲氧基硅烷(MPS)修饰的SBA-15作为基质材料,利用甲基丙烯酸(MAA)和4-乙烯基吡啶(4-VP)双功能单体协同作用的预聚合体系,开发了一种新型的Cr(VI)阴离子表面印迹聚合物(Cr(VI)-IIP)。一系列的表征(FT-IR、EDS、SEM、TEM、小角XRD、N2吸附-脱附分析、TGA)表明表面Cr(VI)印迹聚合物被成功制备以及在印迹聚合后材料仍保持了较规整的介孔结构。静态吸附实验表明,Cr(VI)-IIP在溶液pH=2.0,温度为25 oC的条件下呈现最佳的吸附性能,其饱和吸附容量为96.32 mg g-1。动力学和热力学分析表明,Cr(VI)-IIP对Cr(VI)的吸附分别符合准二阶动力学模型和Langmuir等温吸附模型。在选择性吸附实验中,Cr(VI)-IIP对Cr(VI)阴离子较其他竞争离子(Cr(III)、Cu(II)、Cd(II)、Ni(II))呈现极强的选择性识别能力。在固定床实验中,Cr(VI)-IIP对Cr(VI)阴离子呈现理想的动态吸附性能以及高效的再生能力。(3)我们以一种磁性介孔硅纳米微球(γ-Fe2O3@meso-SiO2)作为基质材料,采用于核壳型纳米颗粒表面引发RAFT聚合的方式,开发了一种新型的表面Cu(II)印迹聚合物,RAFT-IIP。由于RAFT聚合活性、可控的特点,RAFT-IIP比通过传统自由基聚合制备的离子印迹聚合物(TP-IIP)呈现更规则的形貌、更好的单分散性和更强的磁响应性。而且,在静态饱和吸附实验中,RAFT-IIP比TP-IIP呈现更高的吸附容量,分别为210.29 mg g-1和144.84 mg g-1。随后,一系列的吸附实验系统地研究了制备的RAFT-IIP的吸附性能。数据表明,RAFT-IIP具有较强的选择性吸附能力、良好的重复利用性、理想的动态吸附性能,可以作为去除实际水样中Cu(II)的理想的吸附剂。
[Abstract]:Mesoporous materials have been widely used in the adsorption field due to their large specific surface area, fast mass transfer and high adsorption capacity. Especially, silicon-based mesoporous materials have been widely used in the adsorption field because of their abundant silanol-based surface loadings, which provide convenience for further functionalization. In recent years, a large number of heavy metal pollutants have been discharged into the environment along with industrial wastewater, which poses a serious threat to human beings and organisms. Three novel surface ion imprinted polymers were synthesized by using different mesoporous silica substrates, Pb (II), Cr (VI) and Cu (II) as template ions, and their applications in the selective separation of heavy metal ions were discussed. The contents of the study and the experimental results were as follows: (1) Using 3-(2-) Two mesoporous silica adsorbents Pb(II)-IMS-NN and PB(II)-IMS-N with high selectivity for lead ions were prepared by using AAPTS and 3-aminopropyl triethoxysilane (APTES) as functional monomers. Electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), N2 adsorption-desorption experiments and other characterization analysis. Data show that Pb (II) -IMS has a highly ordered mesoporous structure and good thermal stability. In a series of static and dynamic adsorption experiments, Pb (II) -IMS-NN exhibits higher saturated adsorption capacity than Pb (II) -IMS-N and exhibits higher saturated adsorption capacity than Pb (II) -IMS-N. The experimental results show that the breakthrough time increases with the increase of bed height, but decreases with the increase of flow rate and Pb (II) concentration, and Thomas model is more suitable than Adams-Bohart model for describing dynamic adsorption experimental data. NN exhibits superior selectivity and higher affinity to Pb (II) than Pb (II) - IMS - N. (2) A novel Cr (VI) negative polymerization system was developed by using MBA-modified SBA-15 as matrix material and the synergistic effect of MAA and 4-vinylpyridine (4-VP) bifunctional monomers. A series of characterizations (FT-IR, EDS, SEM, TEM, XRD, N2 adsorption-desorption analysis, TGA) showed that the surface Cr (VI) imprinted polymer was successfully prepared and the material maintained a regular mesoporous structure after imprinting polymerization. Static adsorption experiments showed that Cr (VI) IIP was in the solution pH=2.0, the temperature was 25 oC. The adsorption capacity of Cr(VI)-IIP on Cr(VI) was 96.32 mg g-1. The kinetic and thermodynamic analysis showed that the adsorption of Cr(VI)-IIP on Cr(VI) conformed to quasi-second-order kinetic model and Langmuir isothermal adsorption model, respectively. Ni (II) exhibits strong selective recognition ability. Cr (VI) - IIP exhibits ideal dynamic adsorption and high regeneration ability for Cr (VI) anion in a fixed bed experiment. (3) A magnetic mesoporous silica nanosphere (gamma-Fe2O3 @meso-SiO2) was used as a matrix material to initiate RAFT polymerization on the surface of core-shell nanoparticles. A novel surface Cu(II) imprinted polymer, RAFT-IIP, has been developed. Due to its controllable and active RAFT polymerization, RAFT-IIP exhibits more regular morphology, better monodispersity and stronger magnetic responsiveness than TP-IIP prepared by conventional free radical polymerization. Moreover, in static saturated adsorption experiments, RAFT-IIP exhibits better monodispersity and stronger magnetic responsiveness. The adsorption capacity of RAFT-IIP was 210.29 mg-1 and 144.84 mg-1 respectively, higher than that of TP-IIP. Subsequently, a series of adsorption experiments were carried out to systematically study the adsorption properties of the prepared RAFT-IIP. The ideal adsorbent for Cu (II).
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O631;TB383.4
本文编号：2247731
[Abstract]:Mesoporous materials have been widely used in the adsorption field due to their large specific surface area, fast mass transfer and high adsorption capacity. Especially, silicon-based mesoporous materials have been widely used in the adsorption field because of their abundant silanol-based surface loadings, which provide convenience for further functionalization. In recent years, a large number of heavy metal pollutants have been discharged into the environment along with industrial wastewater, which poses a serious threat to human beings and organisms. Three novel surface ion imprinted polymers were synthesized by using different mesoporous silica substrates, Pb (II), Cr (VI) and Cu (II) as template ions, and their applications in the selective separation of heavy metal ions were discussed. The contents of the study and the experimental results were as follows: (1) Using 3-(2-) Two mesoporous silica adsorbents Pb(II)-IMS-NN and PB(II)-IMS-N with high selectivity for lead ions were prepared by using AAPTS and 3-aminopropyl triethoxysilane (APTES) as functional monomers. Electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), N2 adsorption-desorption experiments and other characterization analysis. Data show that Pb (II) -IMS has a highly ordered mesoporous structure and good thermal stability. In a series of static and dynamic adsorption experiments, Pb (II) -IMS-NN exhibits higher saturated adsorption capacity than Pb (II) -IMS-N and exhibits higher saturated adsorption capacity than Pb (II) -IMS-N. The experimental results show that the breakthrough time increases with the increase of bed height, but decreases with the increase of flow rate and Pb (II) concentration, and Thomas model is more suitable than Adams-Bohart model for describing dynamic adsorption experimental data. NN exhibits superior selectivity and higher affinity to Pb (II) than Pb (II) - IMS - N. (2) A novel Cr (VI) negative polymerization system was developed by using MBA-modified SBA-15 as matrix material and the synergistic effect of MAA and 4-vinylpyridine (4-VP) bifunctional monomers. A series of characterizations (FT-IR, EDS, SEM, TEM, XRD, N2 adsorption-desorption analysis, TGA) showed that the surface Cr (VI) imprinted polymer was successfully prepared and the material maintained a regular mesoporous structure after imprinting polymerization. Static adsorption experiments showed that Cr (VI) IIP was in the solution pH=2.0, the temperature was 25 oC. The adsorption capacity of Cr(VI)-IIP on Cr(VI) was 96.32 mg g-1. The kinetic and thermodynamic analysis showed that the adsorption of Cr(VI)-IIP on Cr(VI) conformed to quasi-second-order kinetic model and Langmuir isothermal adsorption model, respectively. Ni (II) exhibits strong selective recognition ability. Cr (VI) - IIP exhibits ideal dynamic adsorption and high regeneration ability for Cr (VI) anion in a fixed bed experiment. (3) A magnetic mesoporous silica nanosphere (gamma-Fe2O3 @meso-SiO2) was used as a matrix material to initiate RAFT polymerization on the surface of core-shell nanoparticles. A novel surface Cu(II) imprinted polymer, RAFT-IIP, has been developed. Due to its controllable and active RAFT polymerization, RAFT-IIP exhibits more regular morphology, better monodispersity and stronger magnetic responsiveness than TP-IIP prepared by conventional free radical polymerization. Moreover, in static saturated adsorption experiments, RAFT-IIP exhibits better monodispersity and stronger magnetic responsiveness. The adsorption capacity of RAFT-IIP was 210.29 mg-1 and 144.84 mg-1 respectively, higher than that of TP-IIP. Subsequently, a series of adsorption experiments were carried out to systematically study the adsorption properties of the prepared RAFT-IIP. The ideal adsorbent for Cu (II).
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O631;TB383.4
【参考文献】
相关硕士学位论文 前1条
1 陈锐;新型环保吸附剂的制备以及对重金属离子的吸附性能研究[D];上海师范大学;2012年
，本文编号：2247731
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