Solvent Mixture Induced Self Assembly of a Terthiophene Based Rod–Coil Block Co-oligomer

Abstract

We describe the synthesis and self-assembly of a terthiophene-oligostyrene based block co-oligomer Ter-OSa. While the self-assembly of block copolymers is normally achieved using block-selective solvents, tetrahydrofuran (THF) is a good solvent for both terthiophene and oligostyrene blocks. The self-assembly in this case arises with the nonsolvent (H(2)O) in THF/H(2)O mixtures. The absorption spectra showed a blue shift and fluorescence spectra showed quenching of fluorescence with increasing water content indicating that the Ter-OSa self-assembled to form H-aggregates. The morphology was studied using scanning electron microscopy. Depending upon the amount of water the Ter-OSa undergoes morphological transition from hollow to rigid spheres. However at higher water content the Ter-OSa formed large spheres from the fusion of smaller spheres. A mechanism of morphological transition from hollow spheres to rigid spheres is proposed.

Optical properties of amphiphilic copolymer-based self-assemblies

“…Polymers with fluorescent and emission functions have enormous advantages over their nonfluorescent analogues [64,65]. The fluorescence and emission properties are derived from the inherent polymer structures, but these properties can be changed dramatically upon aggregation [13].…”

Solvent-dependent nanostructures of gels of a Gemini surfactant based on perylene diimide spacer and oligostyrene tails

“…For example, depending on the relative length of the blocks in polystyrene-bpoly (acrylic acid), morphologies ranging from micelles to vesicles to worm-like structures have been reported. Deepak and Sundararajan [36] attached an oligostyrene segment to terthiophene, and the self-assembly of the terthiophene segment led to solid or hollow spheres depending on the solvent composition. In the present work, we attached oligostyrene to both sides of the PTCDI (OS-PTCDI-OS), to form a Gemini molecule (Scheme 1a).…”

One platform solid multicolour emission of terthiophene compounds controlled by mixed self-assembly

“…According to the literature, the longest lifetime is attributed to emissions from the excimers, which are formed at an intermolecular distance being 4-7Å. 10,11 The uorescence decay data suggest that without DEAB, most TTC4L molecules in the precipitates are in the form of excimers (41.1%), while those in the form of aggregates and monomers are 31.2%, 27.7%, respectively. 7,8 The shortest lifetime belongs to the monomers dispersed in the molecular state in the system.…”