Laser induced periodic surface structures on polymer nanocomposites with carbon nanoadditives

Abstract

Laser induced periodic surface structures (LIPSS) are formed on poly(trimethylene terephthalate) and its composites with single-walled carbon nanotubes (SWCNT) and with both SWCNT and expanded graphite (EG) upon irradiation with a Q-Switched Nd:YAG laser (266 nm, 8 ns). The morphology of the polymer films was characterized by atomic force microscopy. A cantilever with a colloidal probe was used to obtain information about surface adhesion. Surface energies were estimated by contact angle measurements using different liquids. Chemical modification in the materials upon irradiation was assessed by Raman spectroscopy. Results show a dependence of the number of pulses required for LIPSS formation as a consequence of the presence of the carbon nanoadditive and an increase of the hydrophilic character of surfaces after irradiation. Moreover, the polar component of the surface free energy changes significantly and surface adhesion increases by the addition of the additive to the polymer matrix. Additionally, the adhesion force decreases after laser nanostructuring as a consequence of a lower contact area in the nanostructured material.