Thermal conductivity and morphology of silver‐filled multiwalled carbon nanotubes/polyimide nanocomposite films

Abstract

A facile methodology has been developed to synthesize silver-filled multiwalled carbon nanotubes (S-MWNTs)-polyimide (PI) nanocomposites with high thermal conductivity for applications in flexible printed circuits or buried film capacitors, requiring efficient heat dissipation. MWNTs functioned as modules to facilitate the distribution of Ag particles within PI matrix. The intercalation of Ag within MWNTs was performed using capillary action upon mixing AgNO 3 solution with PI precursor and followed by calcinations to reduce the ionic silver to Ag. The existence of Ag in the PI nanocomposites was observed from transmission electron microscope images and verified with the energy-dispersive X-ray spectrometer. Homogeneous dispersion of SMWNTs in PI matrix and strong interaction between S-MWNTs and PI were also suggested by SEM cross-section images. The thermal conductivity of S-MWNT/PI nanocomposite was a function of the content of S-MWNTs in PI matrix. The PI nanocomposite containing 1.5 wt % of S-MWNTs (S-MWNT/PI-1.5) exhibited the highest thermal conductivity, 0.37 W/mK. A decrease in thermal conductivity was observed while the surface roughness of the nanocomposite was higher than 1 lm owing to the high content of S-MWNT in PI. In addition, the modified MWNTs improved flexibility of the PI matrix. V C 2012 Wiley Periodicals, Inc. J Appl Polym Sci 126: E182-E187, 2012

Ultrahigh Thermal Conductivity of Interface Materials by Silver‐Functionalized Carbon Nanotube Phonon Conduits

“…A decrease in σ or κ with the addition of nanoscale conductive fillers above the optimum concentration has also been reported in the literature, and the aggregation of particles and increased interfacial carrier scattering were suggested as possible mechanisms. [19,27,28] The electrical and thermal transport properties of nAg-MWNT-Ag-flake-epoxy and Ag-flake-epoxy TIMs are compared as a function of the curing duration ( Figure 3). As shown in Figure 3a, the σ of nAgMWNT-Ag-flake-epoxy TIMs was [3] orange open up-pointing triangle (silver nanoparticle 45 vol%), [6] blue open down-pointing triangle (aluminum nitride 74 vol%), [7] dark cyan open diamond (iodine-treated silver 35 vol%), [8] wine open star (silver epoxy plus graphene 5 vol%), [9] violet open pentagon (copper nanowire arrays 25 vol%), [10] magenta open left-pointing triangle (graphite 25 vol%), [11] dark yellow open right-pointing triangle (aligned MWNT 16.7 vol%), [12] navy open hexagon (MWNT 25 vol% plus graphene 25 vol%), [13] pink open inverted triangle (silver 70 vol% plus MWNT 3.1 vol%).…”

High conductive Ag nanowire–polyimide composites: Charge transport mechanism in thermoplastic thermostable materials

“…Polyimides present good chemical resistance, high thermal stability, and high mechanical strength. They are widely applied in aerospace as high performance engineering materials and in microelectronic industry as flexible substrates and dielectric layers [4][5][6]. For these applications it is desirable to use polyimides that are soluble in coating and casting processes [7].…”

“…Their dissipation with preservation of mechanical properties is a great challenge. In order to increase the electrical conductivity, carbon black and carbon nanotubes have been already introduced in polyimides [4,5]. For polyimide/carbon nanotube composites, the electrical conductivity reached 10 −5 S•m −1 for 3 wt.% [4] and 10 −4 S•m −1 for 8 vol.% [8].…”

Boron nitride‐graphene sponge as skeleton filled with epoxy resin for enhancing thermal conductivity and electrical insulation

“…In Fig. 9d, if measured by the TC enhancement of filler, it could be calculated that the value was 201, which was one of the highest result at a relatively low filler loading among the previous research focused on the thermal conductive polymeric composites to our best knowledge [7,14,22,[49][50][51][52][53][54][55].…”