武汉纺织大学学报
武漢紡織大學學報
무한방직대학학보
Journal of Wuhan Institute of Science and Technology
2012年
3期
30-33
,共4页
陈晋忠%明瑞豪%吴静%王罗新
陳晉忠%明瑞豪%吳靜%王囉新
진진충%명서호%오정%왕라신
碳纳米管%环氧乙烷%受限作用%阴离子聚合
碳納米管%環氧乙烷%受限作用%陰離子聚閤
탄납미관%배양을완%수한작용%음리자취합
Carbon Nanotube%Ethylene Oxide%Confinement Effect%Anionic Polymerization
采用B3LYP/6-311++G**和ONIOM(B3LYP/6-311++G**:UFF)方法分别对环氧乙烷非受限状态以及在单壁碳纳米管CNT(5,5)内的阴离子聚合反应进行计算。结果表明,环氧乙烷与其亲核试剂(OH-)进攻产物形成的复合物进入CNT(5,5)碳纳米管内是一个放热过程,说明反应复合物进入CNT(5,5)形成包结物在能量上是有利的。由于碳纳米管的限制作用,环氧乙烷阴离子聚合的反应物、过渡态以及产物的结构与非受限状体下有所不同,在碳纳米管内的反应过程中分子构型会发生一定的扭转,以适应碳纳米管内的空间限制。与非受限状相比,环氧乙烷阴离子聚合反应的活化能垒增加了13.2 kcal/mol,表明碳纳米管CNT(5,5)对环氧乙烷阴离子聚合反应起到一定的抑制作用。
採用B3LYP/6-311++G**和ONIOM(B3LYP/6-311++G**:UFF)方法分彆對環氧乙烷非受限狀態以及在單壁碳納米管CNT(5,5)內的陰離子聚閤反應進行計算。結果錶明,環氧乙烷與其親覈試劑(OH-)進攻產物形成的複閤物進入CNT(5,5)碳納米管內是一箇放熱過程,說明反應複閤物進入CNT(5,5)形成包結物在能量上是有利的。由于碳納米管的限製作用,環氧乙烷陰離子聚閤的反應物、過渡態以及產物的結構與非受限狀體下有所不同,在碳納米管內的反應過程中分子構型會髮生一定的扭轉,以適應碳納米管內的空間限製。與非受限狀相比,環氧乙烷陰離子聚閤反應的活化能壘增加瞭13.2 kcal/mol,錶明碳納米管CNT(5,5)對環氧乙烷陰離子聚閤反應起到一定的抑製作用。
채용B3LYP/6-311++G**화ONIOM(B3LYP/6-311++G**:UFF)방법분별대배양을완비수한상태이급재단벽탄납미관CNT(5,5)내적음리자취합반응진행계산。결과표명,배양을완여기친핵시제(OH-)진공산물형성적복합물진입CNT(5,5)탄납미관내시일개방열과정,설명반응복합물진입CNT(5,5)형성포결물재능량상시유리적。유우탄납미관적한제작용,배양을완음리자취합적반응물、과도태이급산물적결구여비수한상체하유소불동,재탄납미관내적반응과정중분자구형회발생일정적뉴전,이괄응탄납미관내적공간한제。여비수한상상비,배양을완음리자취합반응적활화능루증가료13.2 kcal/mol,표명탄납미관CNT(5,5)대배양을완음리자취합반응기도일정적억제작용。
Anionic polymerization mechanism of ethylene oxide(EO) confined inside a single-walled carbon nanotube,CNT(5,5),was calculated at the ONIOM(B3LYP/6-311++G**:UFF) level of theory.Meanwhile,the polymerization of EO in the isolated state was also calculated at the B3LYP/6-311++G** method.We found that the encapsulation process was exothermic and favored in energy when the complex,which was formed by the EO and the EO/nucleophile(OH-) adduct,was entranced into CNT(5,5).Due to the confinement of CNT(5,5),the geometric parameters of reactant,transition state and product within nanotube were different from the corresponding parameters in the isolated state.During the reaction process of EO complex inside nanotube,rotation of the molecular configuration occurred for the EO complex in order to adapt to the inner space of nanotube.The energy calculation showed that the activation energy of the anionic polymerization within nanotube was 13.2 kcal/mol higher than the value in the case of the isolated state,which suggested that that the anionic polymerization of ethylene oxide was inhibited by the confinement in CNT(5,5).