Preparation, characterization, and thermal conductivity of polyvinyl-formaldehyde/MWCNTs foam: A low cost heat sink substrate

Abstract

Preparation of polyvinyl-formaldehyde (PVF)/multi walled carbon nanotubes (MWCNTs) foams as an efficient heat sink nanocomposites was presented here. The PVF foam was loaded with 1 wt%, 2 wt%, and 4 wt% of MWCNTs. Thermal conductivity of the PVF/MWCNTs foams are investigated within the temperature range 25–200 °C. The structure of the prepared foams were characterized by Fourier transform infrared (FTIR), Raman spectroscopy, and differential scanning calorimetry (DSC). The results show that the MWCNTs are homogeneously distributed inside the PVF foam and attached to the PVF matrix via van der Waals forces. The addition of the MWCNTs increased the thermal stability of the PVF foam through connecting and filling the pores of the PVF foam. The maximum thermal conductivity value was found to be ≈5 W/mK for 4 wt% of PVF/MWCNTs foam at room temperature. This value is 166 times higher than the thermal conductivity of neat PVF foam. In addition, this value is higher than that of the previously published values for many carbon nanomaterials (CNMs)/polymer nanocompsites heat sinks. The thermal conductivity of the 4 wt% of PVF/MWCNTs reached 65 W/mK at 200 °C. The 4 wt% PVF/MWCNTs foam lowered the temperature of a hot surface from ≈ 40 to 30 °C, leading to cooling efficiency of 40%. Based on the experimental results, the PVF/MWCNTs foams show an improved capability for heat dissipation through easily and scalable preparation method.

Keywords

• PVF foam
• MWCNTs
• Heat sink
• Thermal conductivity
• Heat dissipation