Development of carboxyl-functionalized multi-walled nanotube/polydimethylsiloxane novel polymeric nanodielectric material

In this paper, we develop a new type of polydimethylsiloxane (PDMS)-based nanocomposite by incorporating carboxyl-functionalized multi-walled nanotube (MWCNT) to the polymer matrix as fillers. The dispersion of MWCNT during the material processing plays a significant role in deciding the final properties of the nanocomposites. A rapid evaporation and stirring method was used to minimize re-aggregation of the fillers during MWCNT/PDMS composites fabrication processing by solution blending. Furthermore, dispersions of MWCNT in solvents were investigated to correlate the degree of dispersion state with Hansen solubility parameters. The result indicated that carboxyl group can impart negative charges and create the long-term electrostatic stability of MWCNT in the solvents. The resultant MWCNT/PDMS composites exhibited high permittivity, low dielectric loss, and low percolation threshold.