Optically observed multiple inter-chain interactions in polyblend semiconducting polymer nanoparticles

Abstract

F8BT:MEH-PPV:CN-PPV semiconducting polymer blend nanoparticles (SPNs) were synthesized with different ratios by a miniemulsion route from three different conjugated polymers; two red/orange emitting polymers; poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and poly(2,5-di(hexyloxy)cyanoterephthalylidene) (CN-PPV), and one green emitting polymer poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT). The resulting SPNs were spherical in shape as determined by transmission electron microscopy, and exhibited tuneable photoluminescence. These optical properties were attributed to the inter-chain interactions between F8BT and the MEH-PPV, and between MEH-PPV and CN-PPV within the same nanoparticle, with no direct interactions happening between the chains of F8BT and the chains of CN-PPV. Therefore, the presence of MEH-PPV within the polyblend SPNs facilitated an indirect F8BT:CN-PPV interaction that was not possible before.