Living Light-Induced Crystallization-Driven Self-Assembly for Rapid Preparation of Semiconducting Nanofibers

Abstract

Well-defined nanostructures composed of conjugated polymers have attracted significant attention due to their intriguing electronic and optical properties. However, precise control of the size and uniformity of these semiconducting nanostructures is still rare and challenging, despite recent advances in strategies to obtain self-assembled nanostructures with narrow dispersions. Herein, we demonstrate the preparation of fluorescent conjugated block copolymers by one-shot polymerization and rapid formation of nanofibers in a few minutes via light-induced crystallization-driven self-assembly, driven by facile cis-to- trans photoisomerization of its poly( p-phenylenevinylene) blocks. Furthermore, living self-assembly was possible, allowing not only nanofibers with excellent length control and narrow size distribution but also ABA triblock comicelles and gradient comicelles, to be produced by seeded growth. Lastly, the seeded growth could be activated and deactivated repeatedly by switching the light on and off, analogous to light-induced living radical polymerization.

Synthesis of Well‐Defined Poly(norbornene) Containing Carbon Nanodots by Controlled ROMP

“…ROMP of NB‐HBC with an M/I ratio of 100 at 0.1 M afforded a polymer molecular weight ( M n ) of 116 kDa with a moderate dispersity of 1.36 (Table , entry 1). To reduce this dispersity, we added a common solvent for ROMP, THF as a cosolvent, but this increased the dispersity to 1.43 (Table , entry 2) presumably due to π–π interaction of the HBC moiety or aggregation of the polymers (see the Supporting Information for further details), causing less ideal polymerization in the less soluble THF (Table , entry 2). To suppress the π–π interactions, we lowered the concentration to 0.05 M in CF and the polymer with a narrow dispersity of 1.24 was prepared with full consumption (Table , entry 3).…”

“…The ROMP of norbornene (NB) derivatives has become a powerful tool to synthesize complex macromolecules including block copolymers, graft‐polymers, and dendronized polymers . Despite the versatility of the ROMP, its synthetic application for the production of polymers with PAH moieties has been rarely investigated.…”

“…14 Another method to improve the solubility is to incorporate the PAH into a polymer backbone as a pendant group, but an additional monomer-bearing solubilizing group is necessary. 15 The ROMP of norbornene (NB) derivatives has become a powerful tool to synthesize complex macromolecules including block copolymers, [16][17][18] graft-polymers, [19][20][21] and dendronized polymers. [22][23][24][25][26] Despite the versatility of the ROMP, its synthetic application for the production of polymers with PAH moieties has been rarely investigated.…”

Continuous and Segmented Semiconducting Fiber‐like Nanostructures with Spatially Selective Functionalization by Living Crystallization‐Driven Self‐Assembly

“…Examples include poly(thiophene), [13] poly(selenophene), [21] poly(fluorene), [22] oligo(phenylene vinylene) (OPV) [23,24] as the p-conjugated block. [25,26] Recently,s everal reports have shown that fiber-like nanostructures of p-conjugated polymers generated via living CDSA with favorable intermolecular spacing, molecular orientation and dimension are promising candidates for the fabrication of flexible organic electronic and optoelectronic devices. [22,26] In addition, it has also been found that the charge carrier mobility of organic field-effect transistors and power conversion efficiency of solar cells can be improved by increasing the width or length of fiber-like nanostructures with ap oly(3-hexylthiophene) core.…”

One‐dimensional growth kinetics for formation of cylindrical crystalline micelles of block copolymers

“…The core crystallinity also plays an important role in the performance of crystalline micelles . Precise control of the dimension of the cylindrical micelles, which is tightly related to the growth kinetics, is of great importance, since it is key to their properties and applications. For example, when used as drug carrier, long cylindrical micelles are more difficult to be up‐taken by cells and have a longer in vivo circulation time, as compared with short rod‐like micelles .…”