Highly Tunable Photoluminescent Properties of Amphiphilic Conjugated Block Copolymers

Abstract

We report a novel class of amphiphilic conjugated block copolymers composed of poly(3-octylthiophene) and poly(ethylene oxide) (POT-b-PEO) that exhibit highly tunable photoluminescence colors spanning from blue to red. POT-b-PEO self-assembles into various well-defined core/shell-type nanostructures as a result of its amphiphilicity. The self-assembly structure can be readily controlled by altering the solvent composition or by other external stimuli. The color change was completely reversible, demonstrating that the strategy can be used to manipulate the light-emission properties of conjugated polymers in a highly controllable manner without having to synthesize entirely new sets of molecules.

Versatile Route to Synthesize Heterobifunctional Poly(ethylene glycol) of Variable Functionality for Subsequent Pegylation

“…corresponding to carbonyl stretching vibration. The reaction of (4) with ammonia in presence of 2-PDS yielded α-azide-ω-pyridyldithio PEG (8). FTIR spectra show complete disappearance of the peak corresponding to carbonyl stretching, Figure 2b.…”

“…α-Pyridyldithio-ω-hydroxyl PEG was recovered by filtration as slightly yellowish solid (1.97 g, 94%). (8). α-Azide-ω-thioacetate PEG (4, 2 g, 1.3 mmol) and 2-PDS (5 eq, 1.44 g, 6.5 mmol) were dissolved in 30 mL ammonia (7 N in MeOH).…”

“…PEG (4), PEG (8), and PEG (9). The α-azide-ω-hydroxyl PEG (2) was used as precursor for the synthesis of α-azide-ω-thioacetate PEG (4).…”

Nanoscale assembly into extended and continuous structures and hybrid materials

“…Such is the case for poly(3-octyl thiophene)-block-poly(ethylene oxide) (P3OT-b-PEO) diblock copolymers prepared by Park et al, 37 in which the assembled structure is controlled by solvent choice and the presence of salt. In a nonselective solvent (tetrahydrofuran), P3OT-b-PEO chains are fully solvated and show orange fluorescence; addition of a solvent highly selective for the PEO block (water) gave spherical aggregates with red fluorescence, while a marginally selective solvent for PEO (methanol) gave fiber-like assemblies with blue fluorescence.…”

Synthesis and characterization of diblock copolymers based on poly(3-hexylthiophene) and photo-responsive poly(methyl methacrylate-random-2-methyl methaspirooxazine)

“…[23][24][25] Recently, diblock copolymers containing conjugated polymers and coil polymers bearing the photochromic functional groups have emerged as a new unique material due to their versatile microphase separation, photo-responsive behavior and possibilities for fine-tuning of the supramolecular architecture of the polymers. [26][27][28][29][30][31][32][33] More recently, it has been reported by Kim and coworkers that a spiropyran-polythiophene photo-switch, where a photochromic spiropyran was introduced as side-chain groups of polythiophene by random-copolymerization of 3HT and a spiropyran-containing thienyl monomer, could highly selectively detect the CN − anion. Hence, the P3HT-b-P(MMA-r-MSp) diblock copolymer may also be used as a sensor probe to detect the toxic anion of CN − .…”