Polymerization-Induced Self-Assembly of Conjugated Block Copoly(phenylacetylene)s

Abstract

Polymerization-induced self-assembly (PISA) was developed to prepare assemblies of conjugated block copoly-(phenylacetylene)s for the first time. The living dispersion polymerization of (R/S)-4-(1-phenethylbamoyl)phenylacetylene (rmAN/smAN) can be achieved in the presence of poly-(phenylacetylene) (PPA) macro-initiators. The assemblies prepared from the copolymers PPA m -b-PrmAN n with the short coreforming PrmAN blocks tended to form vesicles in tetrahydrofuran because of the rigid conformation of the block copolymers. As the length of PrmAN blocks increased, the assemblies preferred to form lamellae, and then, the lamellae twisted to form helical ribbons. The helicity of copolymers could transfer to the helical assemblies accurately. This work not only expanded applications of PISA into living coordination polymerization but also enhanced the efficiency of the assembly preparation of rigid conjugated block copoly(phenylacetylene)s.

Principles and Characteristics of Polymerization-Induced Self-Assembly with Various Polymerization Techniques

“…20 Other PISA principles, such as INCP, are also emerging. 116,118,[154][155][156][157] Here, the π-π interactions between growing polymer chains induce polymer self-assembly. Additionally, CDSA could become an invaluable tool for the preparation of dispersed nanoparticles.…”

Direct formation of nano-objects via in situ self-assembly of conjugated polymers

“…For instance, PPA1 80 -b-PPA2 n formed vesicles (with a PPA2 DP of 136). 71 As the PPA2 block length increased, the vesicles transitioned to ribbons/ lamellae (DP of 190), then helical ribbons (DP of 390, Fig. 9B).…”

“…Unfortunately, reports of using other polymerization methods for INCP (other than ROMP, CP, and CTP) are rare. Two recent examples describe the polymerization of acetylene-based monomers, specifically phenyl acetylenes (PA1 and PA2) 71 and propargyl alcohol (PGA), 72 to give substituted-PA backbones (Fig. 9A).…”

Supramolecular Chirality in Azobenzene-Containing Polymer System: Traditional Postpolymerization Self-Assembly Versus In Situ Supramolecular Self-Assembly Strategy

“…The helicity of the assemblies was detected via CD spectroscopy for all morphologies, proving the helical nature of their main chain formed in PISA process. Furthermore, Wan et al recently reported that PISA strategy can also be employed to prepare main-chain helical assemblies of conjugated poly(phenylacetylene)s [ 239 ], which can self-assemble spontaneously into vesicles, lamellae and helical ribbons with the increase of core-forming blocks length ( Figure 15 c). The chiral properties and the formation of primary helices as main-chain twisted stacks were investigated by TEM and further confirmed by CD data.…”

“…(Red represents solvophobic segments, and blue represents solvophilic segments). (( a ) Reproduced from [ 109 ] with permission from The Royal Society of Chemistry; ( b ) and ( c ), reprinted with permission from [ 238 , 239 ]; Copyright (2020, 2020) American Chemical Society).…”