Tailoring the features of modified polysulfone/carbon filler nanocomposites to enhance physical properties for electronic applications

The article reports the obtaining and characterization of high-performance nanocomposite materials based on modified polysulfone using various amounts of modified carbon nanotube fillers, namely 0.5 wt%, 1 wt%, 2.5 wt %, and 5 wt%. The structures of these systems were simulated and some physico-chemical parameters were estimated, showing the influence of the material composition. The solution casting process was involved for the composite systems preparation. The filler amount affected the structure of the nanocomposites impacting their properties. Raman spectroscopy analysis indicated certain chemical changes in the nanocomposite structures. Thermal characterization showed that nanocomposite's glass transition temperature domain increase with nanofiller content. Mechanical testing indicated an enhancement of the Young's modulus after reinforcing the polymer. Atomic force microscopy stated the presence of the filler in the polymer matrix, the density of the surface features being higher as filler concentration increased. The force curve spectroscopy supported an intensification of the adhesion force measured between the sample and the tip of the cantilever with the increase of the amount of the filler in the nanocomposite, completing the mechanical tests at nanoscale. The electrical permittivity and conductivity of the nanocomposites were investigated by Broadband dielectric spectroscopy at variable electric field frequency. The results revealed a significant enhancement of the electrical conductivity of the studied composite materials, especially at high filler loadings.