【作者】 周立志；

【导师】 平郑骅；

【作者基本信息】 复旦大学 ， 高分子化学与物理， 2005， 博士

【摘要】 有机溶剂脱水是目前渗透蒸发膜分离技术重要的应用领域,针对目前大量应用的亲水聚合物膜稳定性较差,渗透通量小的弊端,本文研制了一种新型的有机-无机复合膜。该复合膜以陶瓷膜为载体,它不仅具有无机膜机械强度大、热稳定性好及化学稳定性高的特点,而且还具备有机聚合物膜选择性高的特点,是一种很有发展前途的亲水性渗透蒸发分离膜。 这种亲水性有机-无机复合膜是以堇青石为基板,通过化学气相沉积或溶胶-凝胶方法在堇青石表面形成具有大量活性硅羟基的SiO₂微孔膜,然后再通过表面的硅烷化反应和自由基接枝共聚反应制成的。硅烷化反应所用的偶联剂是γ-（甲基丙烯酰氧基）丙基三甲氧基硅烷。硅烷化在表面引入具有反应活性的双键,在自由基引发剂存在下,引发接枝亲水性丙烯酸或丙烯酰胺单体,合成了一类新型的亲水性陶瓷载体-高分子复合膜。 论文用硅胶粒子和单晶硅片作为参照物,用FTIR,TGA,XPS,SEM,AFM表面接触角测定仪,椭偏激光仪等方法系统研究了偶联和接枝反应的条件对复合膜性质的影响。复合膜的超薄分离层是由共价接枝在无机膜上的聚合物链组成的。本文着重探讨了单体浓度对反应产物的影响,研究表明,随着接枝单体浓度的增加,膜表面的接枝率增加,接枝层厚度增加,膜的渗透通量减小,分离选择性增大。另外选择不同种类的单体,分离性质亦不同。复合膜的分离性质可通过改变单体种类或单体浓度在较宽的范围内设计调节。复合膜用于醇/水混合物的渗透蒸发分离实验结果表明,这种陶瓷载体-聚丙烯酸或聚丙烯酰胺复合膜用于有机水溶液的脱水有很高的渗透通量和选择性,如在30℃对95wt.%的乙醇水溶液进行处理时,其渗透通量达到0.64 kg.m^-2h^-1,渗透液中的水含量高于98%。是一种性能优异的亲水性渗透蒸发分离膜。聚丙烯酰胺复合膜对丙烯酸水溶液的分离中表现的高选择性和高稳定性是聚合物膜所无法比拟的。论文同时研究了溶液浓度和操作温度的变化对膜的分离性能的影响,并对复合膜的分离机理做了初步的探讨。 论文首次在不含有机模板剂的Na₂O-SiO₂-Al₂O₃-NaCl-H₂O系统中,以堇青石为载体,以水玻璃和准一水软铝石为原料,用水热法合成了ANA沸石膜。研究水含更多还原

【Abstract】 The dehydration of organic solvents by pervaporation through membrane is attracting increasing interest in industry. Most pervaporation studies have involved hydrophilic polymer membranes with high selectivities, but there are drawbacks which include lack of physical and chemical stability. Ceramic membranes are known to have high mechanical and thermal stabilities and a good stability towards organic solvents. However, the ceramic membranes have poor selectivity for its limited selection of pore size. In this paper, a novel hybrid membranes which blend ceramic and polymeric membrane properties have been synthesized.In this paper, the microporous amorphous SiO₂ membrane was prepared on cordierite support by low temperature chemical vapor deposition（LTCVD） and Sol-gel methods,respectively. Surface modification of the support SiO₂ membrane was performed in two steps: surface activation and graft polymerization. A novel hydrophilic ceramic-supported polymer composite membrane was prepared by graft-polymerization of acrylamide or acrylic acid on a microporous silica membrane, which was silylated by γ-（methyl acryloyl） propyl tri-methoxysilane. In order to establish the operating conditions for the considered grafting, Surrogate silica particles and silicon wafer was used as the substrate on which AA or AM was graft polymerized under the same conditions as the ceramic-supported polymer composite membrane. The silylation and graft yield were determined by TGA ,the morphology of the membrane have been analyzed by SEM, AFM , Film thickness of the polymer grafted silicon wafer was measured with ellipsometer, Contact angles for water and hexadecane on the composite membranes were studied. The element composition of the composite membrane was characterized by XPS. It proved that the polymer chains had been successfully grafted on silica membrane, The active ultrathin PAA or PAM separation layers consisted of terminally anchored polymer chains. The graft yield were proportional to the initial monomer concentration, we found that the higher monomer concentration,the higher membrane thickness, the higher selectivity and lower flux. This membrane type is particularly attractive because a wide variety of monomers can be used in the graft polymerization reaction, thereby we can design such membrane for different pervaporation applications. The ceramic-supported polymer composite membrane had been tested in a pervaporation device for dehydration of several other organic solvents. The results showed that the更多还原