基于可聚合表面活性剂有机—无机杂化材料制备研究

【作者】 张龙；

【导师】 胡道道；

【作者基本信息】 陕西师范大学 ， 材料学， 2010， 硕士

【摘要】 可聚合季铵盐表面活性剂不仅具有表面活性剂性质,而且其分子中不饱和双键或叁键,在一定条件下可引发聚合反应。可聚合季铵盐表面活性剂因具有表面活性剂的自组装特性,使其在材料的结构导向方面发挥作用；因其具有电解质的离子交换特性,使其易于引入具有功能性的反离子；因其具有可聚合双键结构,使其易于通过聚合反应对材料进行修饰。因此,可聚合季铵盐表面活性剂在材料功能修饰以及经由自组装制备结构型复合材料方面具有许多优势；有序的自组装表面活性剂相能够为反应提供组成和构建纳米尺寸上可能的反应和模板介质作用,因而引起广‘泛的关注。结合目前燃料油废气排放的新标准,两相催化反应越来越引起人们的重视,随着催化氧化深度脱硫研究的深入,在保证较好催化效率的基础上,寻求一种易于分离氧化产物、并且可以循环利用的两相催化反应体系是当前要亟需解决的首要问题。利用可聚合表面活性剂特殊的结构和性质,再结合本实验室在催化氧化脱硫方面的研究结果,选取了分子体积大、结构稳定、具有催化作用的磷钨杂多酸阴离子(PWA)作为客体,与所合成的可聚合表面活性剂阳离子进行离子交换作用,将两者结合起来形成有机/无机微球材料；以磷钨酸对可聚合表面活性剂3-丙烯酰胺丙基十二烷基二甲基溴化铵(APDDAB)所形成胶束的交联固定作用,借助引发剂引发聚合,从而实现对所形成复合材料结构的调控作用,得到了表面形貌具有规律性变化的聚合材料。以以上方式将催化剂的可收利用和易分离氧化产物两大功能赋予所制备的杂化材料中,以期望解决当前面临的困境。本论文研究工作主要包括以下几个方面的内容：(一)通过季铵化反应成功合成了可聚合表面活性剂APDDAB,并以此季铵盐中的具有电解质离子的交换特性与磷钨酸的阴离子进行离子交换,获得磷钨酸季铵盐微球材料。利用红外光谱、核磁分析、扫描电子显微镜、能谱分析、TGA分析等手段对磷钨酸季铵盐杂化微球材料进行了形貌和结构表征。研究结果表明,在本实验合成条件下,制得的磷钨酸季铵盐杂化微球粒径分布比较均匀,单分散性较好,而且这种微球材料具有较小粒径。(二)利用引发剂引发聚合,制备了不同摩尔比的磷钨杂多季铵盐聚合物(P(PWA-APDDAB)),得到了表面形貌呈现一定规律的杂化材料。以上方法制备的杂化材料经扫描电镜、核磁共振谱仪、光学视频接触角测定仪、热重分析仪、荧光光谱仪、红外光谱仪、压汞仪等多种表征手段对材料的成分和结构测定,证实了所合成的杂化材料是聚合物,而且随着季铵盐的增多,表面形貌具有一定的规律性,同时呈现出一定的孔结构。我们利用所合成的可聚合季铵盐表面活性剂(APDDAB)的自组装特性,使其在材料的表面形貌控制和对材料进行修饰方面发挥重要作用。此聚合材料的制备过程对其他类似复合材料的制备具有重要的借鉴意义。(三)以二苯并噻吩(DBT)的十氢萘溶液为反应模型、以30%H2O2为氧化剂、杂化材料(P(PWA-APDDAB))作为催化剂,考察了反应温度、杂化材料用量、杂化材料组成、H2O2/DBT摩尔比、溶剂中DBT浓度、杂化材料回收利用次数等因素对过氧化氢氧化DBT催化效率的影响。结果表明：不同摩尔比的季铵盐和磷钨酸所形成的催化材料,在两相催化反应中都表现出一定的催化效果。微反应器的不同形貌也影响了催化剂的催化效果,实验条件有待于进一步优化。更多还原

【Abstract】 Polymerizable quaternary ammonium surfactants not only have the feature of the surfactant, but also contain unsaturated double bond or triple bond. It may lead to polymerization under certain conditions,.due to self-assembly property of surfactants. Additionally, polymerizable quaternary ammonium surfactants play an important role in orientationing the materials’ structure.Because of surfactants’ ionic-exchange, polymerizable quaternary ammonium surfactants are liable to introduce a functional counter-ion because of surfactants’ polymerized properties. Polymerizable quaternary ammonium surfactants are easy to modify the materials through the polymerization reactions.These structural features with polymerizable surfactants can promote formating nano-materials possessing many unique structures, including the opening polymer network structure. Compared with conventional methods, such fine structure of the polymer particles with the novel properties of the inorganic/organic nano-structured materials can be obtained. Therefore, the polymerizable quaternary ammonium surfactants have many advantages in terms of functional modification of materials and synthesis of composite materials via self-assembly process. Ordered self-assembled surfactant will be assembled with the possibility of nano-size chemical reaction, and provide the role of template for the media, so it has been drawn more concern among scientists. Combined with current new standard for fuel emissions, there is a growing emphasis on biphasic catalysis reaction, Recently, the study of biphasic catalysis has attracted wide interest. Therefore, enhancement of biphasic catalysis and simplization of process in separation and recovery of the catalysts and products are still need to solve current problems. Based on polymerizable surfactants’ special features and our previous works related to using H2O2 as oxidant in ultra-deep desulfurization of fuel oil, we use phosphotungstic acid with large volume, structural stability and catalytic characteristics, and through ion exchange reaction with polymerizable surfactant cations, which were prepared for organic/inorganic hybrid materials. After that,the desirably and controllably structural composite materials can be abtained by APDDAB and phosphotungstates with the original trigger polymerization. The results indicated that composite materials with regularly changed surface structure were prepared by adjusting the molar ratio between APDDAB and PWA, in order to formate the structure of composite materials.Hybrid materials we prepared have two characteristics:the catalyst can be recycled, and oxidation products can be easily separated after the catalysis reaction, which are long to solve the current dilemma.Based on the idea mentioned above, this research refers to three parts as follows:(1)Through quaternization reaction, the new-type polymerizable surfactant,3-(acryloylamino)propyl dodecyldimethyl ammonium bromide (APDDAB), was synthesized. Then organic/inorganic microspheres were obtained via ion exchange with phosphotungstates (PWA). The microspheres thus prepared were characterized by Fouier transform infrared spectroscopy (FT-IR), Scanning electron microscope(SEM),1HNMR, thermogravimetric analysis (TGA) and elemental analysis, respectively.The results indicated that in our experimental conditions, APDDAB-PWA composite microspheres with different mole ratio were spherical structure, better dispersion and these microspheres have smaller size.(2) With the original trigger polymerization, organic-inorganic hybrid materials with different molar ratio of PWA to APDDAB, and regularly changed surface structure were successfully obtained. The organic-inorganic hybrid materials were futher characterized by Fouier transform infrared spectroscopy (FT-IR), Scanning electron microscope(SEM),1H NMR, thermogravimetric analysis (TGA), Mercury Porosimeters, Fluorescence spectrometer and elemental analysis, respectively.The results indicated that the hybrid materials which we synthesized were polymer, and had regularly changeable surface structure, at the same time, showed a certain degree of pore structure. self-assembly of polymerizable surfactants which played an important role in the modification and structure-orientation of materials. These polymers’ preparation processing is an important reference on other similar materials.(3) The catalytic performances of the poly(APDDAB-PWA) hybrid materials were systematically investigated by using dibenzothiophene (DBT) oxidized by H2O2 in decalin as a model system so that some key factors related to the catalytic performances of the composite microspheres were obtained. The feasibility and regularity of this hybrid material in the biphasic catalysis reaction were further discussed systematicly and detailedly.In the system using (P(PWA-APDDAB)) as microreactor, according to difference between dosages of PWA and APDDAB, the composite materials (P(PWA-APDDAB)) have different surface morphologies. The results indicated that the composite materials used as microreactor has efficient performence in ultra-deep desulfurization of fuel oil, no matter what molar ratioes of materials were used.Meanwhile, the microreactors with different surface morphology also affected DBT oxidation reaction; and proper experimental conditions should be further discussed.更多还原