Self-Assembly of Ionizable “Clicked” P3HT-b-PMMA Copolymers: Ionic Bonding Group/Counterion Effects on Morphology

Abstract

A novel methodology used to overcome the predominance of π–π interactions on the organization of rod–coil copolymer is reported in this paper. We demonstrated changes in the self-assembly morphology of poly­(3-hexylthiophene)-b-poly­(methyl methacrylate) (P3HT-b-PMMA) block copolymer BCP, by introducing an ionic group to the linking unit between the two blocks. A neutral polymer precursor was synthesized from ethynyl-terminated P3HT and azido-terminated PMMA via Huisgen’s 1,3-dipolar cycloaddition. Then two 1,2,3-triazolium-based block copolymers with different counteranions were obtained by a quaternization of 1,2,3-triazole groups with methyl iodide, and subsequent anion exchange was observed with a fluorinated salt, bis­(trifluoromethane) sulfonimide salt. Atomic force microscopy, modulated differential scanning calorimetry, and X-ray scattering were used to prove that the crystallization of the conjugated block is disrupted by the additional ionic interactions imposed to the system. The 1,2,3-triazolium-based BCP with iodide as the counterion exhibited highly organized well-defined fibrils, as the diblock phase segregation χ becomes predominant over the rod–rod interaction μ. When the more stable and larger NTf2 – was used as counterion, P3HT phase was disrupted and no crystallization was observed. This methodology could be a useful strategy to open the range of nanomorphologies reachable with a semiconducting polymer for electronic or photovoltaic applications.

Click chemistry strategies for the accelerated synthesis of functional macromolecules

“…660,661 Moreover, an ionizable triazole junction was utilized to increase χ and suppress π-π interaction of P3HT. 658 In addition to morphological studies, improved charge transport was achieved by vertical alignment of the BCP thin film of semiconducting (holetransporting) poly(N,N 0 -bis(4-methoxyphenyl)-N-phenyl-N 0 -4-triazolylphenyl-(1,1 0 -biphenyl)-4,4 0 -diamine (PDMTPD) conjugated with PSS. 662 These rod-coil BCPs (BCPs) have been applied to organic transistor (oligo-saccharide-b-PS-[o-fluorene]), 663 and Li battery electrode (P3HT-b-PEO) 664 with the role of CuAAC being further extended to fully-conjugated BCPs, including P3HT-b-poly (3-alkoxythiophene) (P3AOT), 665 P3HT-b-poly(9,-9-dioctylfluorene) (P3HT-b-PF), 666 and donorÀacceptor BCPs of P3HT-b-polyperylene bisimide (P3HT-b-PPBI).…”

“…The presence of the coil block effectively suppresses the strong π‐π interaction of conjugated P3AT blocks and results in enhanced charge transport due to improved morphological control. The scope of coil blocks conjugated with P3AT includes poly(styrenesulfonate) (PSS), 657 PMMA, 658 poly(4‐vinylpyridine) (P4VP), 659 and PEG 660,661 . Moreover, an ionizable triazole junction was utilized to increase χ and suppress π – π interaction of P3HT 658 .…”

Brush Polymer of Donor-Accepter Dyads via Adduct Formation between Lewis Base Polymer Donor and All Carbon Lewis Acid Acceptor

“…Therefore, new structural and morphological designs of P3HT-based materials have led to interesting new materials with enhanced performances in OPV devices. To break the limitation of a linear donor polymer and fulfill the diverse requirements in organic electronic devices, polymer structures have focused on the engineering of copolymers having block, graft, or branched architectures [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. Among these structures, incorporation of the conjugated P3HT side chains into a main chain scaffold in the form of a polymer brush has been reported to increase the extent of the conjugated regions so that the resultant polymers have broadened optical absorption [ 24 , 25 , 26 ].…”

Reactive Nanopattern in a Triple Structured Bio-Inspired Honeycomb Film as a Clickable Platform

“…The triazole group is able to be protonated by an acid due to its basic form. [31] [32] A droplet of buffer solution at pH value 1 quickly penetrated the honeycomb film and resulted in a decrease of the contact angle from 84° to 25°, while a droplet at pH value 12 remained stable on the film after a minute (Fig. 3, video available in the SI).…”

“…The increased wettability of the polyelectrolyte nano-domains at the surface resulted in a switch from a Cassie-Baxter state, in which the drop sat on the top of the film and did not penetrate the pores, to a Wenzel state in which the droplet penetrated into the highly porous structure of the honeycomb film (Figure 3). [32][34][35] [36] Because the pores were interconnected (Fig. 1c), the droplet could penetrate below the surface and totally wet the film.…”