Elastomer Nanocomposites with Carbon Nanotubes Modified by Laser Ablation

The effect of laser treatment on the structure and functional properties of multiwalled carbon nanotubes (MWCNTs) synthesized by a microwave method using ferrocene and graphite as precursors, as well as on the electrical and thermophysical characteristics of elastomer nanocomposites based on them, was studied. The MWCNTs were modified by laser ablation using a pulsed Nd:YAG laser with a treatment duration of up to 5 min and a source power of up to 1 kW. The nanocomposites were prepared using the two-component Silagerm 8030 silicone elastomer with a modified MWCNT content of 4 wt %. Scanning electron microscopy and Raman spectroscopy showed that laser irradiation causes significant morphological and structural changes, including a decrease in the nanotube diameter from 40–80 to 20–30 nm due to ablation of the outer graphene layers, the formation of a developed network architecture, the complete removal of catalytic iron particles from the surface, and modification of the defect structure, as confirmed by a shift of the D band from 1345.2 to 1341 cm−1 and an increase in the ID/IG ratio from 1.172 to 1.175, while the position of the G band remains unchanged. The composite containing modified MWCNTs was shown to exhibit improved functional characteristics compared with its unmodified counterparts: the thermal conductivity increased from 0.31 to 0.34 W/(m K), the thermal diffusivity from 1.7 × 10−7 to 1.72 × 10−7 m2/s, and the electrical conductivity from 0.1 to 0.12 S/m. The results indicate that laser treatment is promising for the targeted modification of the morphology and structure of carbon nanotubes to produce electrically conductive polymer composites with improved electrical and thermophysical properties.