量子化学分子动力学模拟SiO_2在高分子绝缘材料中的作用
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- 英文论文题名：QM/MD simulations on the role of SiO_2 in polymeric insulation materials
- 论文作者：王颖
- 英文论文作者：Ying Wang ; State Key Laboratory of Rare Earth Resource Utilization ; Changchun Institute of Applied Chemistry ; Chinese Academy of Sciences
- 年：2016
- 作者机构：中国科学院长春应用化学研究所;
- 论文关键词：聚乙烯 ; 电树枝化 ; 电子亲和势 ; 电离势
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第四十分会：纳米体系理论与模拟
- 语种：中文
- 分类号：TQ325.12;TM21
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十分会 ; 纳米体系理论与模拟
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：295k
- 原文格式：D
- 会议级别：全国
摘要
交联聚乙烯(XLPE)绝缘材料在高压电缆行业得到广泛应用,电树枝老化是导致高压电缆XLPE绝缘性能劣化的主要因素之一,限制了XLPE绝缘电缆的应用。据文献报道,添加SiO2、MgO、ZnO、Al_2O_3、TiO_2、C_(60)和PCBM等可以有效地防止电树枝化和提高击穿强度。但是,由于实验手段的限制,纳米粒子的作用机理尚不明晰。因此,本论文应用紧束缚密度泛函理论计算方法,研究了一系列金属和非金属氧化的电离能、电子亲和势和相对的跃迁难易程度等电学性质,并采用基于紧束缚密度泛函理论的量子化学分子动力学模拟,以Si O2和聚乙烯混合的体系为代表,研究了纳米粒子与聚乙烯之间的微观分子反应机理,揭示了纳米粒子由于电负性的不同优先捕获电子的能力,阐明了尺寸效应的影响,指出了纳米粒子填充提高聚乙烯电树枝化初始时间和初始速度的本质原因,为XLPE在500 k V以上电缆中的应用提供可靠的理论依据。
Quantum chemical molecular dynamics(QM/MD) simulations on SiO_2 filling in the polyethylene(PE) showed that: in the absence of SiO_2, the PE was quickly charged by the high-energy electrons, which resulted in C-C or C-H bonds breaking; On the contrary, in the presence of SiO_2 nanoparticles, electrons trapping and accumulating were dominated by SiO_2 nanoparticles, which made polyethylene be preferentially protected and the initial time of electrical treeing was increased. Furthermore, compared with all investigated nanoparticles, SiO_2 was regarded as the most promising candidate attributing to the highest electron affinity. We further observed that once the high-energy electrons were supersaturated in the nanoparticles, the polyethylene chains would be unavoidably charged and C-H bonds breaking occurred. Following that the polyethylene chains decomposing and cross-linking were involved into the initial growth of electrical treeing. The current observation can be potentially used in power cable insulation.
Quantum chemical molecular dynamics(QM/MD) simulations on SiO_2 filling in the polyethylene(PE) showed that: in the absence of SiO_2, the PE was quickly charged by the high-energy electrons, which resulted in C-C or C-H bonds breaking; On the contrary, in the presence of SiO_2 nanoparticles, electrons trapping and accumulating were dominated by SiO_2 nanoparticles, which made polyethylene be preferentially protected and the initial time of electrical treeing was increased. Furthermore, compared with all investigated nanoparticles, SiO_2 was regarded as the most promising candidate attributing to the highest electron affinity. We further observed that once the high-energy electrons were supersaturated in the nanoparticles, the polyethylene chains would be unavoidably charged and C-H bonds breaking occurred. Following that the polyethylene chains decomposing and cross-linking were involved into the initial growth of electrical treeing. The current observation can be potentially used in power cable insulation.
引文
[1]Han,B.;Jiao M.;Li,C.;Zhang C.;Wu Z.;Wang Y.;Zhang H.RSC Adv.,2016,6:555.