摘要
通过直接碳化由可逆加成-断裂链转移(RAFT)活性自由基聚合制备的聚偏氯乙烯-b-聚乙二醇-b-聚偏氯乙烯共聚物(PVDC-b-PEG-b-PVDC),制备了微孔-中孔复合多孔炭,并对其电化学性能进行了研究。凝胶渗透色谱仪表征表明通过RAFT聚合制得的PVDC-b-PEG-b-PVDC的分子量较高(MnGPC>7000 g?mol-1)、分子量分布较窄(PDI<1.5)。采用热重分析、扫描电镜、N2等温吸脱附法表征了嵌段共聚物的热分解特性和多孔炭的结构,发现PEG链段可完全热分解而具有形成中孔的模板作用,PVDC链段热分解形成含微孔的炭骨架,最终形成兼有微孔和中孔、最大比表面积达1242m2?g-1、孔容达0.49 cm3?g-1的多孔炭。电化学测试表明制备的多孔炭的电化学特性良好,当电流密度为0.5 A?g-1时,PVDC-b-PEG4k-b-PVDC基多孔炭的比电容达到157 F?g-1,显著优于文献报道的PVDC基多孔炭的比电容。
A series of poly（vinylidene chloride） （PVDC） and poly（ethylene glycol） （PEG） consisted triblock copolymers （PVDC-b-PEG-b-PVDC） were prepared via reversible addition-fragmentation chain transfer （RAFT） living radical polymerization. These copolymers were further heated to obtain hierarchical micro- and meso-porous carbons. GPC analysis demonstrated that the prepared PVDC-b-PEG-b-PVDC copolymers had number average molecular weight over 7000 g·mol^-1 with narrow molecular weight distributions （PDI〈I.5）. The morphology and pore structure of the resulted porous carbons were characterized by SEM and N2 absoprtion analysis. The results show that PVDC blocks acts as a good carbon precursor to form micro-pores, and the micro-dispersed PEG blocks act as a meso-pore extender. The prepared carbons show maximum Brunauer-Emmett-Teller surface area of 1242 m^2·g^-1 and pore volume of 0.49 cm^3·g^-1. Moreover, electrochemical measurements show that the porous carbons prepared from VDC blcok copolymers have specific capacitance of 157 F·g^-1 at current density of 0.5 A·g^-1, which is superior than PVDC-based porous carbon reported. The excellent capacitive performance can be attributed to its unique hierarchical porous structure that favors fast diffusion of electrolyte ions.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2015年第4期890-896,共7页
Journal of Chemical Engineering of Chinese Universities
基金
国家自然科学基金(21176209)
关键词
偏氯乙烯
嵌段共聚物
多孔炭
电化学性能
比电容
vinylidene chloride
block copolymer
porous carbon
electrochemical property
specific capacitance
