等离子体羟基化改性纳米SiO_(2)粒子对绝缘纸绝缘特性的影响  

Effect of Plasmas Hydroxylation Modified Nano-SiO_(2)Particles on Insulation Characteristics of Insulating Papers

作　　者：姜楠[1] 李志阳 彭邦发 李杰[1] 吴彦[1] Jiang Nan;Li Zhiyang;Peng Bangfa;Li Jie;Wu Yan(School of Electrical Engineering Dalian University of Technology,Dalian 116024)

机构地区：[1]大连理工大学电气工程学院,大连116024

出　　处：《电工技术学报》2023年第24期6817-6827,共11页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(51877028)。

摘　　要：在绝缘纸中掺杂纳米粒子,可通过其对载流子的限制来提高绝缘纸的绝缘特性。然而,纳米粒子的高比表面积和表面活性易形成“团聚”,导致纳米粒子聚集处易产生局部放电和击穿。为了有效抑制纳米粒子团聚、进一步提高绝缘纸的绝缘特性,利用介质阻挡放电(DBD)等离子体对纳米SiO_(2)粒子进行羟基化改性,增加纳米粒子表面羟基数,并通过氢键与硅烷偶联剂分子发生偶联作用从而桥接在绝缘纸基体上,改善了纳米粒子和绝缘纸的兼容性,从而改善其团聚,并采用原位聚合法制备了掺杂纳米SiO_(2)粒子的纤维素绝缘纸。利用X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)、傅里叶红外光谱仪(FTIR)、比表面及孔隙度分析仪(BET)结合滴定法等手段表征了等离子体改性前后纳米SiO_(2)粒子表面化学组分、微观形貌、官能团及接枝羟基数目的变化规律。并考察了等离子体处理条件及改性步骤对绝缘纸击穿场强和体积电阻率的影响。研究结果表明,纳米SiO_(2)粒子经等离子体羟基化改性后表面氧元素含量及羟基吸收峰显著增强,其在绝缘纸中的分散性得到明显改善。当等离子体改性时间为5 min、空气相对湿度为75%时,纳米SiO_(2)粒子表面接枝的羟基数目达到最高。掺杂了3wt%等离子体羟基化改性的纳米SiO_(2)后,绝缘纸的直流击穿场强和体积电阻率达到18.35 kV/mm和17.45×10^(9)Ω·m,较掺杂了未改性纳米SiO_(2)的绝缘纸分别提高了10.7%和19.4%,较未掺杂纳米SiO_(2)粒子的绝缘纸提高了52.3%和106.2%。In the oil-immersed transformer,the cellulose insulating paper is prone to partial discharge,which makes the insulating paper easy to break down and causes security risks.Therefore,it is important to improve the insulation performance of insulating paper.At present,the primary method is to add inorganic nanoparticles to insulating paper.By doping nanoparticles with a high specific surface area and surface energy in insulating paper,charge carriers can be adsorbed to reduce the energy and thus improve the insulation characteristics of insulating paper.However,the nanoparticle is easy to agglomerate,accumulating charge carriers in the nanoparticle aggregation area,resulting in partial discharge and breakdown.The silane coupling agent is often used to improve the agglomeration of nanoparticles.One end of the silane coupling agent can be combined with the hydroxyl group(−OH)on the surface of nanoparticles through a condensation reaction.The other end of the amino group can be combined with the hydroxyl group on the surface of insulating paper through hydrogen bonding force.Thus,the dispersion of nanoparticles on the surface of insulating paper is improved.However,the hydroxyl content on the surface of inorganic nanoparticles is low.The effect of direct modification with a silane coupling agent could be better,and the activity of the silane coupling agent will decrease with time.If the number of hydroxyls on the surface of nanoparticles can be increased,the effect of the silane coupling agent can be improved.Plasma grafting can graft corresponding functional groups on the surface of materials according to the application requirements,widely used in material surface modification.This paper uses high-frequency AC power to drive the dielectric barrier discharge(DBD)reactor to generate plasma in the humid nitrogen and oxygen mixture.The influence of the surface modification method of nano-SiO_(2)particles on the dispersion of nano-SiO_(2)particles and the insulation characteristics of insulating paper is studied.By graf

关 键 词：等离子体羟基化 纳米粒子改性 分散性 绝缘纸 击穿场强 

分 类 号：TM211[一般工业技术—材料科学与工程]