新型石墨烯化学修饰平台的构筑及其在聚合物复合材料中的应用
发布时间：2018-08-09 20:12
【摘要】：表面修饰能够有效改善石墨烯的溶液加工性、调节石墨烯的带隙、赋予石墨烯特殊的功能性,为石墨烯的有效利用奠定了坚实的基础。石墨烯表面修饰发展至今,已取得了不菲的成绩。美中不足的是,已报道的表面修饰实施方法绝大多数仅针对具体的单一应用目标而开发,较少具备实现多目标任务的能力。就此现状,本项目拟提供一种可供选择的石墨烯表面修饰系统化解决方案,以实现石墨烯在不同场合下的有效利用。其总体思路是,经由表面修饰先获取一种类似于氧化石墨烯(GO)或还原氧化石墨烯(rGO)的表面可再修饰石墨烯材料(modifiable graphene,mG),然后再以该材料为平台通过二次或多次修饰实现期待的石墨烯表面化学再裁制。研究中,采用石墨液相剥离法制取高品质石墨烯,mG的制取选用活性试剂-石墨烯化学修饰方法进行。这不仅在于基于活性试剂的表面修饰方法对石墨烯结构破坏较轻且程度可控,能够为诸如多功能聚合物复合材料等应用领域所需的高品质石墨烯提供制备可能,而且还在于其可通过活性试剂的选择为石墨烯表面化学再裁制提供反应活性点。其中,后者尤为本项目所看重。随后,制取的mG将被用作平台材料,经特定的表面再修饰后获取不同的目标石墨烯材料(modified graphene,MG),研究mG的平台特性;并将特殊分子设计的MG应用到聚合物复合材料中,研究MG相对于未改性石墨烯(pristine graphene,pG)、GO/rGO对复合材料综合性能的提升,证明mG的平台优越性。具体实施过程中,首先基于活性试剂法中的1,3-偶极环加成反应对液相剥离法制备的石墨烯进行修饰,通过合成条件的优化,成功地构建了兼具优异导电性能和分散能力的石墨烯多功能化学修饰平台—2-(3,4-二羟苯基)-吡咯烷(DHPP)接枝石墨烯(G-OH),并利用G-OH结构中不同的活性反应位对石墨烯进行再修饰:利用G-OH结构中酚羟基的活性,通过威廉姆森(Williamson)醚化反应合成了环氧基接枝石墨烯(G-EP),通过酯化反应合成了双键接枝石墨烯(G-MA);利用G-OH结构中酚羟基邻对位氢的活性,实现了热塑性酚醛树脂(Novolak)接枝石墨烯(G-PR)的合成;利用G-OH结构中酚羟基和吡咯烷环与Fe Cl3的络合能力,制备了磁性纳米粒子(G-FeCl3),证明了G-OH的平台特性。随后将G-EP和G-PR分别应用到环氧树脂(EP)和热固性酚醛树脂(Resole)复合材料的制备中,研究发现G-EP和G-PR能够提高复合材料的综合性能,包括力学性能、导电性能、导热性能和热稳定性,特别是在导电和导热性能方面,G-EP和G-PR较pG、GO/rGO更加有效,证明了G-OH的平台优越性。EP/G-EP复合材料和Resole/G-PR复合材料的电导率逾渗阈值分别低至0.16 vol%和0.12vol%。当石墨烯含量为10 wt%时,EP/G-EP复合材料的热导率达到了3.138W·m~(-1)·K~(-1),较纯EP提升了1886%。当石墨烯用量为0.5 wt%时,Resole/G-PR复合材料的热导率达到0.269 W·m~(-1)·k~(-1),较Resole基体提高了156%。最后,为了证明活性试剂法构建高品质石墨烯化学修饰平台的广谱性(Wide-adaptability),又基于活性试剂法中的原位重氮盐反应对石墨烯进行修饰,成功地构建了另一种导电性能和分散能力优异的石墨烯化学修饰平台—苯酚接枝石墨烯(G-phenol)。利用G-phenol结构中酚羟基的活性,通过酯化反应将双键接枝到石墨烯表面,得到产物G-DB,证明了G-phenol的平台特性。将G-DB加入到苯乙烯(St)自由基引发体系,通过原位聚合实现了聚苯乙烯(PS)接枝石墨烯(G-PS)的合成。将G-PS应用到PS复合材料的制备中,研究发现G-PS同样能够提高复合材料的综合性能,而且在提高复合材料导电和导热性能方面,G-PS较pG、GO/rGO同样更加有效,证明了G-phenol平台的优越性。PS/G-PS复合材料的电导率逾渗阈值低至0.22 vol%,在石墨烯含量为2.34 vol%时,复合材料的最终电导率高达95.2 S·m~(-1)。当石墨烯用量为5.0 wt%时,PS/G-PS复合材料的热导率达到0.253 W·m~(-1)·k~(-1),较PS基体的热导率提高了229%。综上,通过活性试剂法能够构建出性能优于GO/rGO的高品质多功能石墨烯化学修饰平台,从而满足石墨烯的不同应用目标需求,而且基于该类化学修饰平台构建的聚合物复合材料较基于pG、GO/rGO平台构建的复合材料在导电和导热性能方面更加优异。
[Abstract]:Surface modification can effectively improve the processing property of graphene solution, regulate the band gap of graphene, give the special functionality of graphene, and lay a solid foundation for the effective use of graphene. The development of the surface modification of graphene has achieved a lot of achievements. This project intends to provide a systematic solution to the surface modification of graphene to achieve effective use of graphene on different occasions. The overall thinking way is to obtain a similar form by surface modification. Graphene oxide (modifiable graphene, mG) is redecorated on the surface of graphene oxide (GO) or reductive graphene oxide (rGO), and then the surface chemical refabrication of expected graphene is realized by two or more modification of the material on the platform. In the study, high quality graphene is prepared by graphite phase stripping method and the selection activity of mG is made. The chemical modification method of the reagent - graphene is carried out. This is not only because the surface modification method based on the active reagent is less destructive and controllable on the structure of graphene, it can provide the possibility for the preparation of high quality graphene, such as multi-functional polymer composites, but also the choice of the active reagent. The surface chemical reactivity of graphene provides reactive active points. Among them, the latter is particularly important in this project. Subsequently, the mG will be used as a platform material to obtain different target graphene materials (modified graphene, MG) after a specific surface modification, to study the platform characteristics of mG, and to apply the MG designed by special molecules to the polymer composite. In the material, the study of MG relative to the unmodified graphene (pristine graphene, pG) and the enhancement of the comprehensive properties of the composite materials by GO/rGO proves the superiority of the mG platform. In the specific implementation process, first, based on the 1,3- dipole ring addition reaction in the active reagent method, the graphene is modified by the liquid phase stripping method, and the synthesis conditions are optimized. 2- (3,4- dihydroxyphenyl) - pyrrolidine (DHPP) grafted graphene (G-OH), which has excellent conductivity and dispersing ability, is constructed, and the modified graphene (G-OH) is redecorated by different reactive sites in the G-OH structure: the activity of phenol hydroxyl in the structure of G-OH, through Williamson (Williamson) ether The synthesis of epoxy based grafted graphene (G-EP) was synthesized by esterification. The synthesis of double bond grafted graphene (G-MA) was synthesized by esterification. The synthesis of thermoplastic phenolic resin (Novolak) grafted graphene (G-PR) was synthesized by the activity of hydroxyl hydroxy ortho para hydrogen in G-OH structure, and the complexing ability of phenol hydroxyl group and pyrrolidone ring to Fe Cl3 in G-OH structure was prepared. Magnetic nanoparticles (G-FeCl3) proved the platform characteristics of G-OH. Subsequently, G-EP and G-PR were applied to the preparation of epoxy resin (EP) and thermosetting phenolic resin (Resole) composites. It was found that G-EP and G-PR could improve the composite properties, including mechanical properties, electrical conductivity, thermal conductivity and thermal stability. In the field of conduction and thermal conductivity, G-EP and G-PR are more effective than pG and GO/rGO. It is proved that the conductivity of G-OH is superior to.EP/G-EP composites and Resole/G-PR composites, the conductivity percolation threshold is lower to 0.16 vol% and 0.12vol%. when the content of graphene is 10 wt%, and the thermal conductivity of the EP/G-EP compound material reaches 3.138W. When the pure EP increased 1886%. when the amount of graphene was 0.5 wt%, the thermal conductivity of the Resole/G-PR composites reached 0.269 W. M~ (-1). K~ (-1), and the Resole matrix increased the 156%. last. In order to prove the broad-spectrum of the high quality graphene chemical modification platform by the active reagent method (Wide-adaptability), and in situ diazo in the active reagent method. Another kind of graphene modified platform, phenol graft graphene (G-phenol), is successfully constructed by the reaction of salt reaction to graphene, which has excellent conductivity and dispersing ability. Using the activity of phenol hydroxyl in the structure of G-phenol, the double bond is grafted onto the Shi Moxi surface by esterification, and the product G-DB is obtained. It is proved that the platform of G-phenol is special. G-DB is added to the styrene (St) free radical initiating system and the synthesis of polystyrene (PS) grafted graphene (G-PS) is realized by in situ polymerization. G-PS is applied to the preparation of PS composites. It is found that G-PS can also improve the comprehensive properties of the composites, and G-PS is more pG in improving the conductive and thermal conductivity of the composite. GO/rGO is also more effective, proving the superiority of the G-phenol platform. The conductivity of.PS/G-PS composites is low to 0.22 vol%. When the content of graphene is 2.34 vol%, the ultimate conductivity of the composite is up to 95.2 S. M~ (-1). When the amount of graphene is 5 wt%, the thermal conductivity of PS/ G-PS composites reaches 0.253 W. The thermal conductivity of the PS matrix is higher than that of the 229%.. Through the active reagent method, the high quality multi-functional graphene chemical modification platform with better performance than GO/rGO can be constructed to meet the needs of different application targets of graphene, and the polymer composite based on this kind of chemical modification platform is more complex than pG based and GO/rGO platform. Composite materials are more excellent in conductivity and thermal conductivity.
【学位授予单位】：青岛科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TQ127.11;TB33
，
本文编号：2175185
[Abstract]:Surface modification can effectively improve the processing property of graphene solution, regulate the band gap of graphene, give the special functionality of graphene, and lay a solid foundation for the effective use of graphene. The development of the surface modification of graphene has achieved a lot of achievements. This project intends to provide a systematic solution to the surface modification of graphene to achieve effective use of graphene on different occasions. The overall thinking way is to obtain a similar form by surface modification. Graphene oxide (modifiable graphene, mG) is redecorated on the surface of graphene oxide (GO) or reductive graphene oxide (rGO), and then the surface chemical refabrication of expected graphene is realized by two or more modification of the material on the platform. In the study, high quality graphene is prepared by graphite phase stripping method and the selection activity of mG is made. The chemical modification method of the reagent - graphene is carried out. This is not only because the surface modification method based on the active reagent is less destructive and controllable on the structure of graphene, it can provide the possibility for the preparation of high quality graphene, such as multi-functional polymer composites, but also the choice of the active reagent. The surface chemical reactivity of graphene provides reactive active points. Among them, the latter is particularly important in this project. Subsequently, the mG will be used as a platform material to obtain different target graphene materials (modified graphene, MG) after a specific surface modification, to study the platform characteristics of mG, and to apply the MG designed by special molecules to the polymer composite. In the material, the study of MG relative to the unmodified graphene (pristine graphene, pG) and the enhancement of the comprehensive properties of the composite materials by GO/rGO proves the superiority of the mG platform. In the specific implementation process, first, based on the 1,3- dipole ring addition reaction in the active reagent method, the graphene is modified by the liquid phase stripping method, and the synthesis conditions are optimized. 2- (3,4- dihydroxyphenyl) - pyrrolidine (DHPP) grafted graphene (G-OH), which has excellent conductivity and dispersing ability, is constructed, and the modified graphene (G-OH) is redecorated by different reactive sites in the G-OH structure: the activity of phenol hydroxyl in the structure of G-OH, through Williamson (Williamson) ether The synthesis of epoxy based grafted graphene (G-EP) was synthesized by esterification. The synthesis of double bond grafted graphene (G-MA) was synthesized by esterification. The synthesis of thermoplastic phenolic resin (Novolak) grafted graphene (G-PR) was synthesized by the activity of hydroxyl hydroxy ortho para hydrogen in G-OH structure, and the complexing ability of phenol hydroxyl group and pyrrolidone ring to Fe Cl3 in G-OH structure was prepared. Magnetic nanoparticles (G-FeCl3) proved the platform characteristics of G-OH. Subsequently, G-EP and G-PR were applied to the preparation of epoxy resin (EP) and thermosetting phenolic resin (Resole) composites. It was found that G-EP and G-PR could improve the composite properties, including mechanical properties, electrical conductivity, thermal conductivity and thermal stability. In the field of conduction and thermal conductivity, G-EP and G-PR are more effective than pG and GO/rGO. It is proved that the conductivity of G-OH is superior to.EP/G-EP composites and Resole/G-PR composites, the conductivity percolation threshold is lower to 0.16 vol% and 0.12vol%. when the content of graphene is 10 wt%, and the thermal conductivity of the EP/G-EP compound material reaches 3.138W. When the pure EP increased 1886%. when the amount of graphene was 0.5 wt%, the thermal conductivity of the Resole/G-PR composites reached 0.269 W. M~ (-1). K~ (-1), and the Resole matrix increased the 156%. last. In order to prove the broad-spectrum of the high quality graphene chemical modification platform by the active reagent method (Wide-adaptability), and in situ diazo in the active reagent method. Another kind of graphene modified platform, phenol graft graphene (G-phenol), is successfully constructed by the reaction of salt reaction to graphene, which has excellent conductivity and dispersing ability. Using the activity of phenol hydroxyl in the structure of G-phenol, the double bond is grafted onto the Shi Moxi surface by esterification, and the product G-DB is obtained. It is proved that the platform of G-phenol is special. G-DB is added to the styrene (St) free radical initiating system and the synthesis of polystyrene (PS) grafted graphene (G-PS) is realized by in situ polymerization. G-PS is applied to the preparation of PS composites. It is found that G-PS can also improve the comprehensive properties of the composites, and G-PS is more pG in improving the conductive and thermal conductivity of the composite. GO/rGO is also more effective, proving the superiority of the G-phenol platform. The conductivity of.PS/G-PS composites is low to 0.22 vol%. When the content of graphene is 2.34 vol%, the ultimate conductivity of the composite is up to 95.2 S. M~ (-1). When the amount of graphene is 5 wt%, the thermal conductivity of PS/ G-PS composites reaches 0.253 W. The thermal conductivity of the PS matrix is higher than that of the 229%.. Through the active reagent method, the high quality multi-functional graphene chemical modification platform with better performance than GO/rGO can be constructed to meet the needs of different application targets of graphene, and the polymer composite based on this kind of chemical modification platform is more complex than pG based and GO/rGO platform. Composite materials are more excellent in conductivity and thermal conductivity.
【学位授予单位】：青岛科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TQ127.11;TB33
，
本文编号：2175185
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