Electrical Properties of Multiwalled Carbon Nanotube Reinforced Fused Silica Composites

Abstract

Multiwalled carbon nanotube (MWCNT)-fused silica composite powders were synthesized by solgel method and dense bulk composites were successfully fabricated via hot-pressing. This composite was characterized by XRD, HRTEM, and FESEM. MWCNTs in the hot-pressed composites are in their integrity observed by HRTEM. The electrical properties of MWCNT-fused silica composites were measured and analyzed. The electrical resistivity was found to decrease with the increase in the amount of the MWCNT loading in the composite. When the volume percentage of the MWCNTs increased to 5 vol%, the electrical resistivity of the composite is 24.99 omega cm, which is a decrease of twelve orders of value over that of pure fused silica matrix. The electrical resistivity further decreases to 1.742 omega. cm as the concentration of the MWCNTs increased to 10 vol%. The dielectric properties of the composites were also measured at the frequency ranging from 12.4 to 17.8 GHz (Ku band) at room temperature. The experimental results reveal that the dielectric properties are extremely sensitive to the volume percentage of the MWCNTs, and the permittivities, especially the imaginary permittivities, increase dramatically with the increase in the concentration of the MWCNTs. The improvement of dielectric properties in high frequency region mainly originates from the greatly increasing electrical properties of the composite.

Development of transparent, conducting composites by surface infiltration of nanotubes into commercial polymer films

“…This compares well with other surface treatments involving graphene oxide-silica composites on glass (45 S/m) [1] and MWCNT-silica composites (57 S/m) [27]. We do note however that these values are low compared to the most conductive polymer-nanotube composites.…”

Graphene−Silica Composite Thin Films as Transparent Conductors

“…Our 11wt % graphene−silica composite spun-cast films have a bulk conductivity of 0.45 S/cm, comparable to the 0.57 S/cm conductivity reported recently for a MWCNT/silica sample (with 9.3 wt % CNT loading) sintered under pressure at elevated temperature. The conductivity of a different MWCNT/silica sample also sintered under pressure and elevated temperature having also 9.3 wt % CNT loading was reported to be ∼1 × 10 -3 S/cm .…”

Silica xerogel films hybridized with carbon nanotubes by single step sol–gel processing

“…Therefore, to take a combined advantage of porous silica films and CNTs, attempts have been made to synthesize CNTs doped porous silica films using methyltriethoxysilane (MTES) as a silica source by single step sol-gel process. The combined effect of silica xerogel and CNTs composites have many probable applications in the fields of photonic, electronic, electromagnetic-interference shielding [7] , mechanical, electrochemical, and optical devices [8][9][10][11][12][13][14][15]. Although the research on the improvement of properties of matrix by the addition of single walled carbon nanotubes (SWCNTs) has been reported, the research on the improvement of properties of matrix by the addition of MWCNTs has relatively not been reported despite of the advantages of using MWCNTs.…”