Polymer-nanoparticle composites composed of PEDOT:PSS and nanoparticles of Ag synthesised by laser ablation

Laser ablation of a solid target material in a liquid environment provides with an easy, straightforward and environmentally friendly method for nanoparticles synthesis as well as with the unique possibility of directly controlling the type of the nanoparticles surface ligands through the liquid choice. In this paper, laser ablation (10.4 ps, 1064 nm and 50 kHz) of a bulk silver target in deionized water, was carried out for nanoparticles synthesis. The synthesised nanoparticles are either pure Ag or A₂O₃ or a mixture of the two materials. Their size distribution follows log-normal function with a statistical median diameter of ≈5 nm. The nanoparticles colloidal solutions were directly mixed after synthesis, with the polymer solution poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) for the formation of polymer-nanoparticles nanocomposite. The nanoparticles readily form bonds with the sulphur atom of PEDOT which results in their uniform distribution within the polymer matrix as well as in a replacement by the nanoparticles of the PSS⁻ as the counteranions to the PEDOT⁺. These effects result in the reduction of the effective insulation of the polymer blend particles by the insulating PSS and furthermore in the electrical conductivity of the nanocomposite becoming higher (by ∼1.5 times) as compared with that of the pure polymer.