镍/硅橡胶复合材料阈值附近的压敏和介电行为研究
|
摘要
采用不同粒径亚微米镍粉与硅橡胶按质量比为2∶1,2.8∶1进行配料,经过特殊的制备方法,制备成镍/硅橡胶高分子复合材料,并主要研究了复合材料的压敏性能和介电性能.通过对材料做性能测试发现当用亚微米镍粉做导电填料时,复合材料具有优异的压敏性能:当仅对材料施加一个200 k Pa压强时,质量比为2.8∶1的镍(400纳米填料)/硅橡胶复合材料的电导率变化了9个数量级.同时,材料的压敏性能会随着导电填料粒径的变化而发生变化.为了充分研究材料的电学性能,实验分别测量出在不同压强下材料的电导率、介电常数随频率的变化数据,研究发现:当频率和压强发生变化时,材料的电导率和介电常数也会发生变化,表现出不同的电荷输运机制.
A series of nickel / silicone rubber composites with different submicron filler diameter and Ni / silicone mass ratio 2∶ 1,2. 8∶ 1were prepared. The dielectric permittivity and conductivity of the composites were studied. It was found that the composites show good piezoresistivity: the conductivity of the composites with mass ratio of nickel / silicone rubber under 2. 8 ∶ 1( 400 nm diameter filler)changed 9 orders under a low pressure around 200 k Pa. Furthermore,the piezoresistivity of the composites changed with the diameter of the fillers. In order to study the conductivity of the materials thoroughly,the frequency dependence of the conductivity and the dielectric permittivity of the composites under different pressures were studied,which showed that the conductivity and dielectric permittivity of the composites changed with measuring frequencies and pressure,presenting different charge transport mechanisms.
A series of nickel / silicone rubber composites with different submicron filler diameter and Ni / silicone mass ratio 2∶ 1,2. 8∶ 1were prepared. The dielectric permittivity and conductivity of the composites were studied. It was found that the composites show good piezoresistivity: the conductivity of the composites with mass ratio of nickel / silicone rubber under 2. 8 ∶ 1( 400 nm diameter filler)changed 9 orders under a low pressure around 200 k Pa. Furthermore,the piezoresistivity of the composites changed with the diameter of the fillers. In order to study the conductivity of the materials thoroughly,the frequency dependence of the conductivity and the dielectric permittivity of the composites under different pressures were studied,which showed that the conductivity and dielectric permittivity of the composites changed with measuring frequencies and pressure,presenting different charge transport mechanisms.
引文
[1]Ishigure Y,Iijima S.,Ito H,et al.Electrical and elastic properties of conductor-polymer composites.J.Mater.Sci.1999,34:2979-2985.
[2]Panda M,Srinivas V,Thakur A K.Role of polymer matrix in large enhancement of dielectric constant in polymer-metal composites.Appl.Phys.Lett.2011,99:042905.
[3]Rizvi R,Cochrane B,Biddiss E,et al.Piezoresistance characterization of poly(dimethyl-siloxane)and poly(ethylene)carbon nanotube composites.Smart.Mater.Struct.2011,20:094003.
[4]Yoshikawa S,Ota T,Newnham T.Piezoresistivity in polymer-ceramic composites.J.Am.Ceram.Soc.1990,73:263-267.
[5]Chang C M,Liu Y L.Electrical conductibity enhancement of polymer/multiwalled carbon nanotuve(MWCNT)composites by thermally-induced defunctionalization of NWCNTs.ACS.Appl.Mater.Inter.2011,3:2204-2208.
[6]Shang S M,Gan L,Yuen M C,et al.Carbon nanotubes based high temperature vulcanized silicone rubber nanocomposite with excellent elasticity and electrical properties.Comps.Part A-Appl.S.2014,66:135-141.
[7]Stassi S,Canavese G.Spikey nanostructured metal particles as filler of polymeric composites showing tunable electrical conductivity.J.Polym.Sci.Part B:Polym.Phys.2012,50:984-992.
[8]Chen L,Chen GH,Lu L.Piezoresistive behavior study on finger-sensing silicoen rubber/graphite nanosheet nanocomposites.Adv Funct Mater2007,17:898-904
[9]Hwang J,Jang J,Hong K,et al.Poly(3-hexylthiophene)wrapped carbon nanotube/poly(dimethylsiloxane)composites for use infinger-sensing piezoresistive pressure sensors.Carbon 2011,49:106-10.
[10]He F,Lau S,Chan H L,et al.High dielectric permittivity and low percolation threshold in nanocmposites based on poly(vinylidene fluoride)and exfoliated graphite nanoplates.Adv.Mater.2009,21:710-715.
[2]Panda M,Srinivas V,Thakur A K.Role of polymer matrix in large enhancement of dielectric constant in polymer-metal composites.Appl.Phys.Lett.2011,99:042905.
[3]Rizvi R,Cochrane B,Biddiss E,et al.Piezoresistance characterization of poly(dimethyl-siloxane)and poly(ethylene)carbon nanotube composites.Smart.Mater.Struct.2011,20:094003.
[4]Yoshikawa S,Ota T,Newnham T.Piezoresistivity in polymer-ceramic composites.J.Am.Ceram.Soc.1990,73:263-267.
[5]Chang C M,Liu Y L.Electrical conductibity enhancement of polymer/multiwalled carbon nanotuve(MWCNT)composites by thermally-induced defunctionalization of NWCNTs.ACS.Appl.Mater.Inter.2011,3:2204-2208.
[6]Shang S M,Gan L,Yuen M C,et al.Carbon nanotubes based high temperature vulcanized silicone rubber nanocomposite with excellent elasticity and electrical properties.Comps.Part A-Appl.S.2014,66:135-141.
[7]Stassi S,Canavese G.Spikey nanostructured metal particles as filler of polymeric composites showing tunable electrical conductivity.J.Polym.Sci.Part B:Polym.Phys.2012,50:984-992.
[8]Chen L,Chen GH,Lu L.Piezoresistive behavior study on finger-sensing silicoen rubber/graphite nanosheet nanocomposites.Adv Funct Mater2007,17:898-904
[9]Hwang J,Jang J,Hong K,et al.Poly(3-hexylthiophene)wrapped carbon nanotube/poly(dimethylsiloxane)composites for use infinger-sensing piezoresistive pressure sensors.Carbon 2011,49:106-10.
[10]He F,Lau S,Chan H L,et al.High dielectric permittivity and low percolation threshold in nanocmposites based on poly(vinylidene fluoride)and exfoliated graphite nanoplates.Adv.Mater.2009,21:710-715.