RESUMEN
A novel approach to obtaining nanocomposite materials using anionic sequential polymerization and post-synthetic esterification reactions with chemically modified graphene sheets (CMGs) is reported. The anionically synthesized diblock copolymer precursors of the PS-b-PI-OH type were grafted to the chemically modified -COOH groups of the CMGs, giving rise to the final composite materials, namely polystyrene-b-poly(isoprene)-g-CMGs, which exhibited enhanced physicochemical properties. The successful synthesis was determined through multiple molecular characterization techniques together with thermogravimetric analysis for the verification of increased thermal stability, and the structure/properties relationship was justified through transmission electron microscopy. Furthermore, the arrangement of CMGs utilizing lamellar and cylindrical morphologies was studied in order to determine the effect of the loaded CMGs in the adopted topologies.
RESUMEN
The effect of impurities on the optoelectronic and charge transport properties of semiconducting polymers was investigated through the performance of organic photovoltaics (OPVs) and organic field effect transistors (OFETs), respectively. A model representative semiconducting polymer, i.e., poly(3-hexylthiophene) (P3HT), was synthesized and purified using different methods such as precipitation, metals' complexation, and Soxhlet extraction. After the purification processes, each fraction was analyzed to determine its composition in metals (impurities) by various techniques. OFETs and OPVs fabricated from these purified polymer fractions were found to show different charge carrier properties and photovoltaic behaviors. The purest fraction which was obtained after Soxhlet extraction complemented by metals' complexation with the help of ethylenediamine and 15-crown-5 ether showed the best performance in both OPVs and OFETs.