【作者】 林德荣；

【导师】 胡立江； Baoshan Xing；

【作者基本信息】 哈尔滨工业大学 ， 化学工程与技术， 2013， 博士

【摘要】 随着现代工业的高速发展，工业废水量逐年增多，而这些工业废水中大多含有难降解的有机污染物（POPs），容易造成环境污染，进而危害人体健康。因此，如何去除POPs是当下世界性工业化城市共同面临的一个难题。本文研究的桥联倍半硅氧烷（BPS）有序介孔材料具有吸附POPs的能力，它以有机桥联三乙烷基[(R’O)3Si-R-Si(OR)3]为有机硅的先驱体，采用了溶胶-凝胶法和模板法分别形成高度有序的两类不同结构（六方和立方）的介孔材料，并对BPS材料进行了吸附实验，研究显示BPS有序介孔材料能有效的吸附POPs，这在水处理研究领域预期具有重要的理论价值，在环保领域有着可观的应用前景。采用溶胶-凝胶法，在四氢呋喃溶液中，以甲酸为催化剂，(EtO)3Si(CH2)3NH-CONH(CH2)11CH3为单体，通过水解缩合，合成了双缩脲桥联基BPS六方有序纳米介孔材料。双缩脲基团之间的氢键及尾对尾连接有机链通过BPS自组装形成了纳米棒状结构。把超薄碳膜上沉积的BPS胶体浸没在甲醇里面，待室温干燥后，纳米BPS粒子形成咖啡环状结构。采用红外、核磁硅谱、小角X射线衍射、透射电镜、高分辨透射电镜、选区电子衍射等实验仪器对合成的纳米棒状结构进行了测试表征。结果显示双缩脲基BPS有序介孔材料具有六方有序纳米结构，高的比表面积和较窄的孔径分布。采用两种模板合成法，一种是在酸性条件下，以甲烷基、乙烷基、己烷基、辛烷基、苯基和联苯基三乙氧基硅烷为先驱体，聚(氧乙烯)十六烷基醚（Brij56）为模板剂，合成了空间群为Pm3n的三维BPS立方有序介孔材料；另一种是在碱性条件下，以1，6-二（三乙氧基硅烷基）己烷（BESH）为先驱体，N-(3-三甲基氨丙基)十六铵二溴和十六烷基三甲基溴化铵为模板剂，合成了空间群为Pm3n的三维BPS立方有序介孔材料。采用小角X射线衍射和透射电镜等手段对样品进行了测试表征。酸性及碱性条件下合成的BPS材料具有高度有序的立方介孔结构、高的比表面积和狭窄的孔径分布。另外，老化时间、老化温度、BESH的浓度、去离子水及氢氧化钠摩尔量，均影响己烯基BPS材料介孔相的形成及其表面的结构性能。利用合成的BPS有序介孔材料分别对含苯有机污染物（硝基苯、2，4-二氯苯酚（DCP）、芘和菲）进行了吸附实验。采用高效液相色谱、紫外可见分光光度计等仪器对实验结果进行了测试分析。研究表明：联苯基及苯基的BPS介孔材料比双缩脲基、己烯基和辛烯基的BPS有更高的吸附量；BPS有序介孔材料的疏水性能对芘、菲、硝基苯和DCP等POPs的吸附起主要作用，π–π键和氢键作用次之。同时，POPs的辛醇水分配系数（Kow)、溶剂性能和分子尺寸等对BPS有序介孔材料吸附芘、菲、硝基苯和DCP有一定影响。BPS有序介孔材料对含苯有机污染物（菲、DCP和硝基苯）的竞争吸附主要受孔阻断和吸附位点的影响。对己烯基BPS有序介孔材料竞争吸附菲、DCP和硝基苯进行了吸附机理研究。采用高效液相色谱、紫外可见分光光度计等仪器对实验结果进行了测试分析。研究表明：经过7d的竞争吸附实验，己烯基BPS有序介孔材料对菲和DCP及菲和硝基苯竞争吸附的饱和吸附量均下降了；较大的介孔孔体积能够减轻孔阻断的影响；含苯有机污染物的分子重量差异也会导致不同程度的孔阻断。此外，理论模型和数值公式解释了观察到的孔阻断和位点竞争吸附现象。更多还原

【Abstract】 With the rapid development of modern industry, most of the industrialwastewater containing persistent organic pollutants (POPs) cause environmentalpollution, which harm human health. Therefore, POPs removal is a major challengein the world’s industrialized cities. The bridged silsesquioxane (BPS) mesoporousmaterials can adsorb POPs. Organic-inorganic hybrid materials were accomplishedby using an organic bridged triethyl [(R’O)3Si-R-Si(OR)3] as the organosilicaprecursor, sol-gel and alkyl chain surfactants as the template. surfactant wasremoved to yield highly order hexagonal and cubic mesoporous materials;Meanwhile, the hexagonal and cubic mesoporous materials were selected foradsorption and competitive adsorption experiments, which are expected in the fieldsof water treatment research and environment that have important theoretical valueand considerable potential applications.In this paper, a silsesquioxane was synthesized by the hydrolysis andpolycondensation of (EtO)3Si(CH2)3NHCONH(CH2)11CH3in tetrahydrofuran (THF)employing formic acid as catalyst. The silsesquioxane self-assembled into nanorodsdue to the strong H-bonds among urea groups and the tail-to-tail associations oforganic chains. The biuret BPS material was characterized by a variety ofexperimental techniques (FTIR,(29)Si NMR, XRD, TEM. HRTEM, and SAED). Acolloidal solution of the silsesquioxane in methanol was deposited on a carbon filmgenerating coffee ring structures with nanoparticles located at the boundary of rings.The result showed that the sample was ordered hexagonal mesopore that wasconfirmed by small angle X-ray scattering and transmission electron microscopy.Nitrogen adsorption analysis of the biuret BPS revealed their high surface area andmesopore.Three-dimensional cubic (Pm3n) periodic mesoporous bridged silsequioxane(BPS) with methylene, ethylene, hexylene, octylene, phenyl, and biphenyl-bridginggroup were synthesized using the five different types of silsequioxane precursors inthe presence of a Brij56(Polyethylene glycol Monocetyl ether, n=23) under acidiccondition. Three-dimensional cubic (Pm3n) periodic mesoporous BPS wassynthesized by condensation of1,6-bis(triethoxysilyl) hexane (BESH) in thepresence of hexadecyltrimethyl ammonium bromide (CTAB) andN-(3-trimethyl-ammoniumpropyl) hexadecyl ammonium dibromide (C16-3-1) underbasic conditions. The BPS mesoporous materials were characterized by a variety ofexperimental techniques (FTIR, small angle XRD, TGA,TEM.). Highly ordered3Dcubic (Pm3n) mesostructure was confirmed by small angle X-ray scattering and transmission electron microscopy. Nitrogen adsorption analysis of the methylene,ethylene, hexylene, octylene, phenyl, and biphenyl bridging samples revealed theirhigh surface area and accessible mesopores. The ageing duration, ageingtemperature, concentration of BESH, amount of water and amount of NaOH werevaried systematically in order to study their effects on the mesophase formed and onthe surface properties of the materials synthesized.Biuret, hexylene, octylene, phenyl and biphenyl BPS mesoporous materialswere selected for adsorption of pyrene, phenanthrene, nitrobenzene, and2,4-dichlorophenol (DCP). The adsorption properties were analyzed by a variety ofexperimental techniques (HPLC and UV-1750). Rigid aromatic BPS (phenyl andbiphenyl) showed higher sorption capacity than soft aliphatic BPS (biuret,hexylene and octylene). Hydrophobic interaction dominantly controlled organicpollutants’ sorption on BPS. Other interactions, e.g. π–π interactions, H-bondinteractions, also have effects on sorption as indicated by Kownormalized sorptionisotherms. Meanwhile, adsorption of pyrene, phenanthrene, nitrobenzene and DCPon BPS was greatly affected by adsorbate properties, i.e. Kow, solvation propertiesand molecular size.In this study, the pore blockage and site competition effect of hexylene BPS onphenanthrene,2,4-Dichlorophenol (DCP) and nitrobenzene adsorption isothermwere investigated. Hexylene BPS was tested to determine the roles of hexylene BPSpore size distribution and molecular weight distribution in the pore blockagemechanism. The adsorption properties were analysed by a variety of experimentaltechniques (HPLC and UV-1750). A decrease in phenanthrene, DCP andnitrobenzene removal was observed in a continuous sway hexylene BPS system afterallowing7days of contact. A hexylene BPS with a relatively large fraction ofmesopores was shown to suffer much less from the pore blockage effect comparedwith a hexylene BPS that had a much smaller fraction of mesopores. The hexyleneBPS with different organic pollutants molecular weight distribution caused differentextents of pore blockage. A conceptual model and formulae were proposed tofurther explain the observed phenomena.更多还原