【作者】 沈剑锋；

【导师】 叶明新；

【作者基本信息】 复旦大学 ， 材料物理与化学， 2010， 博士

【摘要】 碳材料在宇宙中广泛存在,其奇异独特的物性和多种性随人类文明的进步而逐渐被认识和利用。本文通过对两种纳米碳材料-碳纳米管(CNT)和石墨烯的制备、修饰和初步应用进行探讨,系统地研究了CNT和石墨烯这两种新型的材料,并通过一系列的测试手段对两者进行平行研究,比较两者的不同性能。具体研究内容如下：(1)在CNT的修饰及初步应用研究中,通过多步反应的方法对CNT进行纯化,同时引入羧基和羟基等官能团,使修饰后的CNT分散性大大加强。通过酰氯化和氨基化进一步对羧基化CNT进行修饰,制备得到氨基化CNT；利用原子转移活性聚合技术制得活性大分子引发剂,再在CNT上原位接枝聚苯乙烯-聚丙烯酰胺双亲性嵌段共聚物；通过原位聚合的方法制备带正电和负电的聚电解质/CNT复合材料,并分别在平面和球体上进行层层自组装；通过熔融混合环氧树脂与氨基化CNT制备复合材料。制备过程中控制温度、浓度比例提高复合材料的热学、力学性能。利用差示扫描量热仪、热失重分析、弯曲强度测试等研究不同氨基化CNT对环氧树脂的热学、力学性能影响；利用混合还原剂原位还原的方法将Pt-Co催化剂沉积在CNT表面,从而制备新型直接氧化甲醇的催化剂,并对其催化性能和抗一氧化碳中毒性能进行研究。(2)在石墨烯的制备、修饰及初步应用研究中,将石墨与过氧化苯甲酰反应制得氧化石墨,超声制得氧化石墨烯(GOS)后原位还原制得石墨烯并对其反应机理进行研究；利用原子转移活性聚合技术制得活性大分子引发剂,再在石墨烯上原位接枝聚苯乙烯-聚丙烯酰胺双亲性嵌段共聚物,对其水溶性和油溶性进行研究；通过将GOS与溴代正丁烷反应制备烷基修饰亲油性石墨烯；通过两步二酰亚胺活化酰胺化制备了亲水性和亲油性的化学修饰石墨烯；通过原位聚合的方法制备带正电和负电的聚电解质/石墨烯复合材料,并进行层层自组装研究；高温下通过将乙酰丙酮铁在1-甲基毗咯烷酮溶剂中,在GOS表面沉积磁性纳米粒子制备GOS/磁性纳米粒子的复合材料,并对其磁学性能进行研究；通过原位还原的方法制备银纳米粒子/化学改性石墨烯的复合材料并对其表面增强拉曼效应及杀菌性能进行研究；利用混合还原剂原位还原的方法将Pt-Co催化剂沉积在石墨烯上制备新型直接氧化甲醇的催化剂,并对其催化性能和抗一氧化碳中毒性能进行研究；通过两步二酰亚胺活化酰胺化将牛血清白蛋白共价接枝到GOS表面并对其生物活性进行研究。更多还原

【Abstract】 Carbon is a basic and important element on earth. Carbon nanostructures in zero, one and two dimensions offer great potential in a broad range of applications. In this paper, we studied the preparation, modification and primary application of two carbon nanomaterials:carbon nanotubes (CNTs) and graphene. The detail research contents and results are summarized as follows:(1) Through series of steps, the raw material of CNTs were purified and carboxyl and hydroxyl were introduced, which greatly improved solubility and stability of CNTs dispersion. Functionalization of CNTs with amine groups was achieved after such steps as carboxylation, acylation and amidation; The grafting of polystyrene-polyacrylamide block copolymer to single walled carbon nanotubes (SWCNTs) was achieved by in situ living free radical polymerization. The resulting dispersions were stable and had homogeneous dark ink-like appearance, consisting mainly of long isolated nanotubes and thin bundles; Anionic and cationic CNTs/polyelectrolytes, prepared by covalent modification of CNTs with poly(acrylic acid) and poly(acrylamide), were used for the layer-by-layer (LBL) self-assembly of CNTs on different substrates, such as glass and PS colloids; Nanotube-reinforced epoxy composites were prepared by mixing amino-functionalized CNTs with epoxy resin. Differential scanning calorimetry, thermogravimetric analysis and bending tests were used to investigate the thermal and mechanical properties of the composites. The results showed that different kinds of amino-functionalized CNTs would have different effects on the thermal and mechanical properties of the composites; Catalyst of Pt-Co supported on single-walled carbon nanotubes (SWCNTs) is prepared using mixed reducing agents. Under same Pt loading mass and experimental conditions, the SWCNTs-Pt-Co catalyst showed higher electro catalytic activity and improved resistance to CO poisoning than the SWCNTs-Pt catalyst.(2) A massively scalable, fast and facile method for preparation of graphene oxide sheets (GOS) and graphene nanoplatelets was achieved. The basic strategy involved the preparation of graphite oxide (GO) from graphite through reaction with benzoyl peroxide, complete exfoliation of GO into GOS, followed by their in-situ reduction to individual graphene nanoplatelets. The mechanism of GOS producing is mainly the generation of oxygen-containing groups on graphene sheets; The grafting of polystyrene-polyacrylamide (PS-PAM) block copolymer to graphene nanoplatelets was achieved by in situ living free radical polymerization. This method is beneficial because the amphiphilic property of the block copolymer can help to stabilize graphene nanoplatelets in both polar and non-polar solvents; Organophilic chemically functionalized graphene (OCFG) sheets were achieved through such steps as complete exfoliation of GO into GOS, followed by reacting with 1-Bromobutane to get OCFG sheets; hydrophilic and organophilic chemically modified graphene sheets were prepared through a two-step diimide-activated amidation. The dispersions are homogeneous and exhibit long-term stability, which facilitate their combination with polymers to yield homogeneous composites; graphene nanoplatelets were self-assembled through LBL method. Anionic and cationic graphene-containing polyelectrolytes, prepared by covalent modification of graphene sheets with poly (acrylic acid) and poly (acryl amide), were used in the cyclic dispersion procedures; Magnetic GOS were prepared by attaching magnetic nanoparticles to GOS through high temperature reaction of ferric triacetylacetonate with GOS in 1-methyl-2-pyrrolidone; Catalyst of Pt-Co binding on GOS was prepared using mixed reducing agents and their activity in the electro-oxidation of methanol was studied. It was found that the presence of GOS leads to higher activity, which might be due to the increase of electrochemically accessible surface areas and easier charge-transfer at the interfaces. An in situ chemical synthesis approach was proposed to prepare Ag/chemically converted graphene (CCG) nanocomposites. The reducing process of GOS was accompanied by generation of Ag nanoparticles. Raman signals of CCG in such nanocomposites are greatly increased by the attached silver nanoparticles, displaying surface-enhanced Raman scattering activity. In addition, it was found that the antibacterial activity of Ag nanoparticle still exists, which is promising to be used as graphene-based biomaterials; GOS were functionalized by bovine serum albumin (BSA) via diimide-activated amidation under ambient conditions. The obtained GOS-BSA conjugates are highly water-soluble, forming brown-colored aqueous solutions. Results of cyclic volatammograms showed that the protein in the GOS-BSA conjugates retains its bioactivity.更多还原