碳纳米管、石墨烯导电增强磺化聚苯胺复合材料的制备与性能

IMR OpenIR

	碳纳米管、石墨烯导电增强磺化聚苯胺复合材料的制备与性能
	张坤
学位类型	硕士
导师	成会明 ; 杜金红
	2010
学位授予单位	中国科学院金属研究所
学位授予地点	北京
学位专业	材料学
关键词	磺化聚苯胺多壁碳纳米管石墨烯导电性成膜性
摘要	"聚苯胺（PANI）由于原料廉价易得、合成简便、通过调节质子酸掺杂具有较高的导电性等优点，是最具有应用前景的导电高分子材料之一。其缺点是不溶于水和普通有机溶剂，在熔融加工时不稳定，因而很难加工成型，限制了其广泛应用。磺化聚苯胺（SPANI）是聚苯胺的衍生物，具有优异的水溶性。但是由于磺酸基团的磺化效应，其导电性比较低。碳纳米管（CNT）和石墨烯（GNS）均具独特的结构，易于形成导电网络，而且还具有π共轭结构，可与SPANI形成π-π相互作用,在提高SPANI导电性的同时改善与其的界面结合，提高其机械性能。因此，本文提出了以CNTs和GNS为导电添加剂制备同时具有水溶性和导电性的SPANI/CNT和SPANI/GNS复合材料，对其结构和性能也进行了表征。主要研究结果如下：采用化学原位聚合法，以十六烷基三甲基溴化铵（CTAB）作为CNTs和GNS的分散剂，草酸作为PANI的掺杂剂，制备了PANI/CNT、PANI/GNS复合材料。再经氯磺酸磺化制得了SPANI/CNT和SPAN/GNS复合材料。扫描电镜和高分辨透射电镜观察发现SPANI均匀的包覆在CNT和GNS表面。SPANI/CNT为核-壳结构，包覆层厚度为1-3 nm；SPAN像丝绸样包覆在GNS的表面。紫外-可见光谱、红外光谱、Raman光谱研究发现，SPANI与CNTs和GNS之间存在着π-π相互作用，稳定了SPANI分子链中的醌式结构，提高了其质子酸掺杂水平，有利于提高SPANI的导电性。导电性研究发现：同样采用化学原位聚合法制备的PANI的电导率为7.06×10-3 S/cm，磺化后的SPANI的电导率降低为3.2×10-5 S/cm。而CNTs和GNS的加入均可显著提高SPANI的导电性。其中，SPANI/MWCNT的电导率为4.45 S/cm，不仅比SPANI高出五个数量级而且比PANI还高出约三个数量级；将CNTs石墨化后采用相同参数和步骤制备的复合材料具有更高的电导率（11.43 S/cm）；SPANI/GNS的电导率较低，为2.8×10-2 S/cm，与PANI在一个数量级。 SPANI/CNT和SPANI/GNS复合材料在水溶液中均可稳定存在。SPANI/CNT在水溶液中的溶解度为1 mg/ml，SPANI/GNS的溶解度为0.8 mg/ml。采用真空抽滤成膜，结果发现SPANI/CNT水溶液可成均匀、有光泽、具有一定柔韧性的薄膜。这对其在电磁屏蔽、金属防腐等领域的应用具有重要意义。然而SPANI/GNS复合材料的成膜性较差。"
其他摘要	"Polyaniline (PANI) is one of the most promising conducting polymers because of its merits of cheap monomer, easy preparation, high electrical conductivity and unique redox properties. However, it is insoluble in water and common organic solvents and infusibility makes it difficult to be processed. Sulfonated polyaniline (SPANI) , the derivative of polyaniline, has good water solubility. However, its electrical conductivity is low due to sulfonic effect. Carbon nanotube (CNT) and graphene nanosheet (GNS) both have unique structure and excellent electrical conductivity which make them promising conductive fillers for polymer matrices. Moreover, due to the conjugation structure of CNT and GNS, π-π interaction between either of them with SPANI may occur and further improve the conductivity and mechanical properties of SPANI.In this thesis, SPANI/CNT, and SPANI/GNS composites were synthesized with an attempt to improve the electrical conductivity of SPANI with good water solubility, and their structure and properties were characterized. A chemical “in-situ” polymerization method was used to synthesize the PANI/CNT and PANI/GNS composites , using cetyltrimethylammonium bromid (CTAB) as the dispersion agent of CNT and GNS, and oxalic acid as the dopant. Then the obtained composites were sulfonated with chlorosulfonic acid. After hydrolysis, the SPANI/CNT and SPANI/GNS composites were obtained. SEM and HRTEM observations demonstrate that SPANI uniformly covered on the surface of the CNT and GNS. And SPANI/CNT composite has a “core-shell” structure, in which the shell thickness is about 1-3 nm. SPANI on the surface of GNS is like silk. UV-Vis, FTIR, Raman spectroscopy characterizations demonstrate that π-π interaction exists between SPANI and CNT and GNS, which stabilizes the quinoid structure and improves the protonic acid doping effect of SPANI. Electrical conductivity of the composites were investigated, and the results demonstrate that the obtained composites have excellent electrical conductivity. SPANI/CNT has a volume conductivity of 4.45 S/cm which is five orders of magnitude higher than SPANI (3.02×10-5 S/cm) and three orders of magnitude higher than PANI (7.06×10-3 S/cm). SPANI/CNT composite in which CNTs were graphitized has a higher volume conductivity of 11.43 S/cm. SPANI/GNS composite also has a higher volume conductivity of 2.8×10-2 S/cm than that of SPANI, but is relatively lower than that of SPANI/CNT. All of the SPANI/CNT and SPANI/GNS composites can form stable aqueous solution as SPANI covering on the surface of CNTs and GNS. The solubility of SPANI/CNT composite is about 1 mg/ml. while SPANI/GNS composite has a water solubility of 0.8 mg/ml. To investigate processibility of SPANI/CNT and SPANI/GNS composites, a vacuum filtration method was used to prepare the composite film. A uniform and glazed film with an extent of flexibility can be obtained from the aqueous solution of SPANI/CNT. It is meaningful for its practical useage in the fields of electromagnetic shielding and metal corrosion protection. In contrary, SPANI/GNS is poor in the film formation."
文献类型	学位论文
条目标识符	http://ir.imr.ac.cn/handle/321006/64228
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	张坤. 碳纳米管、石墨烯导电增强磺化聚苯胺复合材料的制备与性能[D]. 北京. 中国科学院金属研究所,2010.