Solvent-Induced White-Light Emission of Amphiphilic Rod–Rod Poly(3-triethylene glycol thiophene)-block-poly(phenyl isocyanide) Copolymer

Abstract

A class of amphiphilic rod−rod diblock copolymers composed of hydrophilic π-conjugated poly(3triethylene glycol thiophene) (P3(TEG)T) and hydrophobic rigid-rod-like poly(phenyl isocyanide) (PPI) was synthesized in one pot via mechanistically distinct, sequential block copolymerization with Ni(dppp)Cl 2 as a single catalyst. The hydrophilic P3(TEG)T homopolymer self-assembled into well-defined nanoparticles in THF and methanol with different dimensions and exhibited orange-light emission in THF and red-light emission in methanol. Interestingly, the resultant P3(TEG)T-b-PPI block copolymers were found to self-assembled into various well-defined supramolecular structures, such as nanofibrils in THF, micelles in methanol, and vesicles in 3/2 mixtures of THF and methanol. The assemblies of these block copolymers in solutions exhibited unique light emissions with the emission color spanned widely from orange red to blue depending on self-assembled morphology and solvents used. White light emission can be readily achieved through the control of self-assembled morphologies by variation on the solvent composition. Moreover, the light emissions of the block copolymers were completely reversible, demonstrating the tunable emissions were indeed ascribed to the morphological transitions of the block copolymer.

Fabrication of a multi-charge generable poly(phenyl isocyanide)-block-poly(3-hexylthiophene) rod–rod conjugated copolymer

“…4b shows a luminous yellow emission under UV illumination at 365 nm and no remarkable changes could be observed when the content of added water in the THF solution was less than 5%, which was distinct from the pink light emitting color with 40% water content. 37,71 This phenomenon is well in accordance with the reported poly(3-triethylene glycol thiophene) (P3(TEG)T) homopolymer when the solvent is transferred from THF to methanol. The emission properties were further confirmed by fluorescence spectroscopy (Fig.…”

“…This indicates that the small amount of water could not induce any assembly of the amphiphilic PPI(-QDMAENBA/ DMAENBA)-b-P3HT block copolymers. 37 Simultaneously, these short wavelength emission peaks were similar to that of thiophene oligomers, and the conjugation length of some P3HT was partially reduced by rotational defects in the micellar aggregates, which disrupts the planarity of P3HT. 4c).…”

“…36,37 The hydrolysis reaction was then performed with trifluoroacetic acid to afford carboxyl group functionalized PPI(-AA)-b-P3HT diblock copolymers (2). This methodology is more advantageous than the conventional chain extension from a purified macroinitiator, which is always accompanied by the existence of inseparable homopolymer impurities.…”

“…37,69,70 Herein, the emission properties of PPI(-QDMAENBA/DMAENBA)-b-P3HT block copolymer with a 40% degree of quaternization were investigated in the mixture solvents of THF and water. 37,69,70 Herein, the emission properties of PPI(-QDMAENBA/DMAENBA)-b-P3HT block copolymer with a 40% degree of quaternization were investigated in the mixture solvents of THF and water.…”

Recent advances in the solution self‐assembly of amphiphilic “rod‐coil” copolymers

“…Based on these affecting factors, this subsection starts with the description of controllable self‐assembly of amphiphilic rod‐coil linear BCPs containing thiophene type blocks, as they represent the most extensively studied π‐conjugated polymer system in recent years . For example, Patra et al synthesized poly(3‐hexylthiophene)‐ block ‐poly(dimethylsiloxane) (P3HT‐ b ‐PDMS) diblock copolymers .…”