Molecular dynamics simulations of conducting polymer nanocomposites

Among the conducting polymers, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is one of the most used materials in the field of bioelectronics due to its biocompatibility, chemical stability and high electronic as well as ionic charge transport mobilities. Despite many experimental findings, a microscopic understanding of the materials electronic properties is currently elusive; the main reason is the lack of structural atomistic data of the polymer blend, that is, difficult to obtain because of the disordered and nano-crystalline morphology. In this thesis work we develop and use Molecular Dynamics based methods to simulate the structure of PEDOT:PSS in presence of an interface, investigating how a surface and some physical quantities (temperature, water content and electric charge on PEDOT oligomers) would introduce order to the evolving structure, and pointing out the differences between interfacial and bulk behaviour. The results obtained by computer simulations are used to estimate experimentally accessible parameters and to compare them with already existing experimental data.