摘要
研究了石墨、聚合物（ＰＶＡ）及材料厚度对石墨－ＭＤＦ（Ｍａｃｒｏ－Ｄｅｆｅｃｔ－Ｆｒｅｅ）水泥基复合材料屏蔽电磁波性能的影响及其机理．结果表明；当石墨添加量超过１８ｖ．％时，材料对２００—１６００ＭＨｚ的电磁波有１０—４０ｄＢ的衰减效果，屏蔽效率Ｓ随材料中聚合物增加而降低，随材料厚度增加而升高，随电磁波的频率ｆ的增加有升高的趋势．当石墨在水泥基体里形成导电网络时，材料的电阻车ρｖ发生显著变化，即出现渗滤阈值（ＰｅｃｏｌａｔｉｏｎＴｈｒｅｓｈｏｌｄ）现象后，具有较好的屏蔽性能，屏蔽电磁波主要以吸收电磁波为主．
The influence of the volume percent of graphite and polymer(PVA)on the electromagnetic interference shielding effectiveness of the Graphite-MDF cement composite was investigated. The results show if the volume percent of graphite is over 18v.%. S is about 10-40dB in the range of 200-1600MHz electromagnetic wave. S increases with the increasing of the thickness of the composite and electromagneticwave frequency, and decreases with the increasing of polymer (PVA)volume percent. When graphite particles form the conducting network and the resistivity of the composites (ρv) change drastically. i.e.occurs the pecolation threshold phenomenon. the composites behave a better shielding effect. and the electromagnetic interference shielding effectiveness of the composite depands mainly on adsorbing the electromagnetic wave.
出处
《材料研究学报》
EI
CAS
CSCD
1995年第3期284-288,共5页
Chinese Journal of Materials Research
