【作者】 王明；

【导师】 王志；

【作者基本信息】 天津大学 ， 化学工程， 2018， 博士

【摘要】 CO₂分离膜技术是实现CO₂减排、能源气体净化以及CO₂资源化利用的关键。混合基质膜具有良好的工业应用前景,膜内相界面对膜性能有重要影响,但目前还缺乏对聚合物与无机纳米填料界面形态及其与混合基质膜气体传递性能关系的系统研究,导致提高混合基质膜性能缺少理论依据和指导方法。针对此问题,本文考察了多种混合基质膜中聚合物-填料界面形态及其对膜气体传递性能的影响,分析了界面形成机理,提出了定量判定界面空隙通道大小的方法。首先,以聚乙烯基胺（PVAm）为连续相,以多壁碳纳米管（MWCNT）、二氧化硅（SiO₂）、ZSM-5、胺化多壁碳纳米管（MWCNT-NH₂）、胺化二氧化硅（SiO₂-NH₂）和胺化ZSM-5（ZSM-5-NH₂）分别作为分散相,在聚砜（PSf）超滤膜上采用刮涂法制备了一系列PVAm基混合基质复合膜。考察了填料种类对聚合物-填料界面的影响,讨论了混合基质复合膜分离层可能存在的结构及其气体传递机理,提出了通过分析纯气体渗透数据判定界面空隙通道大小的方法,也考察了进料气压力对膜气体渗透选择性能的影响,结果表明PVAm与填料间的作用力和压力均影响界面形态,界面形态对PVAm基混合基质复合膜的气体传递性能有重要影响,通过分析随压力升高膜纯气体渗透性能的变化可以判定界面形态,在填料表面引入与聚合物相同的功能基团是提高界面相容性的有效方法。其次,以聚醚共聚酰胺（Pebax 1657）为连续相,以MWCNT、SiO₂和ZSM-5分别作为分散相,在PSf超滤膜上采用刮涂法制备了一系列Pebax基混合基质复合膜。考察了填料种类、填料含量和膜厚度对界面形态的影响,讨论了填料严重团聚的混合基质复合膜分离层可能存在的结构及其气体传递机理,也考察了进料气压力、填料含量和膜厚度对膜的气体渗透选择性能的影响,结果表明Pebax与填料间的作用力、填料含量、膜厚度和压力均影响界面形态,随着填料含量增加,填料团聚严重,团聚体间界面形态变得很重要,界面形态对Pebax基混合基质复合膜的气体传递性能有重要影响。再次,以聚醚砜（PES）为连续相,以MWCNT、SiO₂和ZSM-5分别作为分散相,采用刮涂法制备了一系列PES基混合基质膜。考察了填料种类和填料含量对界面形态的影响,考察了进料气压力和填料含量对膜的气体渗透选择性能的影响,结果表明PES与填料间的作用力和填料含量均影响界面形态,界面形态对PES基混合基质膜的气体传递性能有重要影响。最后,比较了不同聚合物基混合基质膜界面形态及其构效关系,结果表明聚合物类型影响界面形态及其构效关系。更多还原

【Abstract】 The membrane-based technology for CO₂ separation is a key for CO₂ mitigation,energy gas purification and CO₂ utilization.Mixed matrix membranes（MMMs）have good perspective in industrial application.Phase interface in MMMs has an important effect on membrane performance.However,a systematic research is lacking on interface morphologies between polymers and nanofillers and effects of interface morphologies on gas transport properties of MMMs,which results in lack of theoretical basis and guidelines on improving membrane performance.To solve the problem,interface morphologies between polymers and nanofillers and effects of interface morphologies on gas transport properties of several kinds of MMMs were explored,interface formation mechanism was suggested,and a method of quantitative assessing the size of interface void channels was proposed.Firstly,a series of polyvinylamine（PVAm）based mixed matrix composite membranes were fabricated by knife coating method on polysulfone（PSf）ultrafiltration membranes.PVAm was chosen as a continuous phase,and multiwalled carbontube（MWCNT）,silica（SiO₂）,ZSM-5,amine group-functionalized multiwalled carbontube（MWCNT-NH₂）,amine group-functionalized silica（SiO₂-NH₂）,and amine group-functionalized ZSM-5（ZSM-5-NH₂）were chosen as a dispersed phase,respectively.Effects of different types of nanofillers on interface morphologies between polymer and nanofillers were explored.Possible separation layer structures of mixed matrix composite membranes and their gas transport mechnisms were discussed,and the method of assessing the size of interface void channels was proposed by analyzing pure gas permeation data.Effects of feed gas pressure on gas permeance and selectivity of the membranes were also explored.Results indicate that interaction beteween PVAm and nanofillers and pressure both affect interface morphologies,and interface morphologies play an important role in gas transport of the PVAm based mixed matrix composite membranes.Analyzing the changes in pure gas permeance of the membranes with increasing pressure can estimate interface morphologies.Surface modification of inorganic nanofillers endowed with the same functional groups as polymer is an effective approach to improve polymer-filler interface compatibility.Secondly,a series of poly（ethylene oxide-b-amide-6）（Pebax）based mixed matrix composite membranes were fabricated by knife coating method on PSf ultrafiltration membranes.Pebax 1657 was chosen as a continuous phase,and MWCNT,SiO₂ and ZSM-5 were chosen as a dispersed phase,respectively.Effects of different types of nanofillers,nanofiller loading and membrane thickness on interface morphologies were explored.Possible separation layer structures of mixed matrix composite membranes with serious agglomerates of fillers and their gas transport mechnisms were discussed.Effects of feed gas pressure,nanofiller loading and membrane thickness on gas permeance and selectivity of the membranes were also explored.Results indicate that interaction between Pebax and nanofilllers,nanofiller loading,membrane thickness and pressure all affect interface morphologies.Nanofillers agglomerate seriously,and interagglomerates interface morphologies become very important with increasing nanofillers loading.Interface morphologies play an important role in gas transport of the Pebax based mixed matrix composite membranes.Thirdly,a series of polyethersulfone（PES）based MMMs were fabricated by knife coating method.PES was chosen as a continuous phase,and MWCNT,SiO₂ and ZSM-5 were chosen as a dispersed phase,respectively.Effects of different types of nanofillers,and nanofiller loading on interface morphologies were explored.Effects of feed gas pressure and nanofiller loading on gas permeance and selectivity of the membranes were also explored.Results indicate that interaction between PES and nanofilllers and nanofiller loading both affect interface morphologies,and interface morphologies play an important role in gas transport of the PES based MMMs.Finally,interface morphologies in different polymer-based MMMs and their structure-property relationships were compared.Results indicate that different types of polymers affect interface morphologies and their structure-property relationships.更多还原