Wu and coworkers investigated the morphologies and optical properties of PPE based triblock copolymers with different sequences, PS-b-OPE-b-PS (coil–rod–coil) and OPE-b-PS-b-OPE (rod–coil–rod), in different mixtures of toluene and hexane [91]. For PS-b-OPE-b-PS, the two PS coil-end blocks could wrap the OPE middle block to make the conjugated OPE backbone more stiff and planar. However, the intrachain wrapping prevented a parallel alignment of OPE and suppressed the π–π interaction, resulting in red shifts in its absorption and photoluminescence (PL) spectra. For OPE-b-PS-b-OPE, the two conjugated OPE end blocks could undergo a parallel intrachain association in dilute solution to form π–π stacking, stabilized by the PS block. The addition of hexane could also induce interchain parallel association of OPE to form a disk-like core stabilized by a PS shell. The J-type aggregation shifted the spectra of PS-b-OPE-b-PS to red, while the H-type aggregation shifted the spectra of OPE-b-PS-b-OPE to blue ( Fig. 16). As a result, they revealed that the packing of the conjugated rod was strongly affected by the copolymer chemical architecture, even in a given solvent mixture.