Electrical Conductivity in Polymer Blends∕ Multiwall Carbon Nanotubes

A unique approach was adopted to drive the multiwall carbon nanotubes (MWNTs) to the interface of immiscible PVDF–ABS blends by wrapping the nanotubes with a mutually miscible homopolymer (PMMA).

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Fabrication of Metal Alloy-Deposited Flexible MWCNT Buckypaper for Thermoelectric Applications

Journal of Nanomaterials ◽

10.1155/2013/635647 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

Jih-Hsin Liu ◽

Hsin-Yuan Miao ◽

Saravanan Lakshmanan ◽

Li-Chih Wang ◽

Ren-Hui Tsai

Keyword(s):

Carbon Nanotubes ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermal Evaporation ◽

Multiwall Carbon Nanotubes ◽

Metal Alloys ◽

Thermal Evaporation Method ◽

In Series ◽

Multiwall Carbon ◽

Temperature Resistivity

We report the fabrication of a flexible network of multiwall carbon nanotubes (MWCNTs) known as buckypaper (BP) for thermoelectric (TE) applications. A thermal evaporation method was used to deposit TE metal alloys onto the BP. The TE properties were improved primarily by increasing the Seebeck coefficient values (50 and 75 μV/K) and the electrical conductivity by approximately 10 000 S/m. High-temperature resistivity studies were performed to confirm the semiconductivity of buckypaper. Variations in resistivity were observed to be the result of the metal alloys coated on the BP surface. We also demonstrated that a substantial increase in the Seebeck coefficient values can be obtained by connecting 3 and 5 layers of metal-deposited BP in series, thereby enhancing the TE efficiency of MWCNT-based BP for application in thermoelectric devices.

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Incorporation of Functionalized Multiwall Carbon Nanotubes into a Polyurethane Matrix

Advances in Materials Science and Engineering ◽

10.1155/2013/929865 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

Martin Michálek ◽

Michael Bredol

Keyword(s):

Carbon Nanotubes ◽

Electrical Conductivity ◽

Percolation Threshold ◽

Aqueous Suspension ◽

Sodium Dodecyl ◽

Multiwall Carbon Nanotubes ◽

Glass Substrates ◽

Functionalized Mwcnts ◽

Multiwall Carbon

Functionalized and raw multiwall carbon nanotubes (MWCNTs) were investigated colloid-chemically in order to study the role of polar versus nonpolar interaction with a polyurethane (PU) matrix. Both kinds of MWCNTs were dispersed by ultrasonication in the presence of a surfactant (sodium dodecyl sulphate) in aqueous solution. Functional groups on the nanotube surface were characterized by infrared spectroscopy and by theζ-potential in aqueous suspension. Such suspensions were added to waterborne PU dispersions, drop-cast on glass substrates and cured. The percolation threshold for electrical conductivity with polar (functionalized) MWCNTs was reached at 0.24 wt.%, whereas at concentrations as high as 2 wt.%, PU films with nonpolar MWCNTs stayed below the percolation threshold. With an addition of 0.4 wt.% polar MWCNTs, the electrical conductivity increased to >10−6 S/cm in the cured coating layer. These results are interpreted with respect to the chemical nature of the PU matrix.

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