Tailoring the Self‐Healing Properties of Conducting Polymer Films

Abstract

shown recently that adding the biocompatible polymer polyethylene glycol (PEG) to PEDOT:PSS aqueous suspensions yields softer films showing autonomic healing. [19] It had been reported that PEDOT:PSS mixed with the surfactant Triton X-100 forms a conducting polymer dough that is capable of recovering current autonomically, due to enhanced viscoelasticity. [18,20] Moreover, a PEDOT:PSS hydrogel, formed by mixing PEDOT:PSS aqueous suspension and 4-dodecylbenzenesulfonic acid (DBSA), achieves both electrical and mechanical healing after cutting and pasting. [21] Cao et al. reported a stretchable PEDOT:PSS hydrogel in poly(N-isopropyl acrylamide) (PNIPAM) matrix can be healed at room temperature without external stimulus due to multiple dynamic hydrogen bonds among PSS − @PNIPAM shells. [22] Although autonomic or water-induced healing has been demonstrated for several PEDOT:PSS formulations, some important questions remain unanswered. For instance, it is still unclear how the healing process is affected by compounds added during PEDOT:PSS film processing to modify the film adhesion properties, such as crosslinkers, or by treatments carried out to increase the electrical conductivity, such as acid soaking. [23-31] Moreover, it is unclear if self-healing properties extend to other forms of PEDOT containing counterions other than PSS, obtained by chemical or electrochemical polymerization. Such forms of PEDOT are of interest since in small dopants, such as para-toluene sulfonate (or tosylate, Tos), trifluoromethanesulfonate (or triflate, OTf), and ClO 4 − , lead to an enhanced electrical conductivity (>1000 S cm −1) due to a more compact PEDOT-PEDOT stack. [32-34] In this work, we studied the water-enabled self-healing of the following systems: PEDOT:PSS films processed in presence of the crosslinker 3-(glycidyloxypropyl)trimethoxysilane (GOPS); PEDOT:PSS films post-treated with sulfuric acid; PEDOT:Tos and PEDOT:OTf films obtained by chemical polymerization; and PEDOT:ClO 4 obtained by electrochemical polymerization. We showed that i) the presence of GOPS in the film as well as a long post-treatment with sulfuric acid significantly impair the healing ability; ii) films of PEDOT:Tos as well as PEDOT:OTf show water-enabled healing; iii) electropolymerized PEDOT:ClO 4 films do not show water-induced healing. The self-healing properties were found to be strictly related The conducting polymer polyethylenedioxythiophene doped with polystyrene sulfonate (PEDOT:PSS) has received great attention in the field of wearable bioelectronics due to its tunable high electrical conductivity, air stability, ease of processability, biocompatibility, and recently discovered self-healing ability. It has been observed that blending additives with PEDOT:PSS or post-treatment permits the tailoring of intrinsic polymer properties, though their effects on the water-enabled self-healing property have not previously been established. Here, it is demonstrated that the water-enabled healing behavior of conducting polymers is decreased by crosslinke...

Thermally driven self‐healing PEDOT conductive films relying on reversible and multiple Diels–Alder interaction

“…At present, self-healing polymers employing PEDOT as electroconductive components have been reported. [15][16][17][18][19][20][21][22][23][24] However, these research generally were on the basis of commercial available poly (3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), an aqueous dispersion purchased from Clevios™, and their films or elastomers. [15][16][17][18][19][20] Their self-healing attributed to water-driving swelling of thermoplastic and hydrophilic PSS À chains together with noncovalent hydrogen-bonding interactions, which can be enhanced if combining with heating.…”

“…[15][16][17][18][19][20][21][22][23][24] However, these research generally were on the basis of commercial available poly (3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), an aqueous dispersion purchased from Clevios™, and their films or elastomers. [15][16][17][18][19][20] Their self-healing attributed to water-driving swelling of thermoplastic and hydrophilic PSS À chains together with noncovalent hydrogen-bonding interactions, which can be enhanced if combining with heating. [18][19][20] In addition, some surfactants, crosslinking biomolecules, or other additives to increase the viscoelasticity of composite materials also have been studied.…”

“…[15][16][17][18][19][20] Their self-healing attributed to water-driving swelling of thermoplastic and hydrophilic PSS À chains together with noncovalent hydrogen-bonding interactions, which can be enhanced if combining with heating. [18][19][20] In addition, some surfactants, crosslinking biomolecules, or other additives to increase the viscoelasticity of composite materials also have been studied. [21][22][23][24] Although the self-healing PEDOT:PSS composite prepared by above-mentioned methods showed good processability and conductivity due to the use of Clevios PH1000 with the highest film conductivity (up to 1000 S/cm), they cannot be repaired under mild conditions without water driving.…”

Fabrication of an autonomously self-healing flexible thin-film capacitor by slot-die coating

“…To finalize the fabrication of the device, PEDOT:PSS, a conductive polymer known for its self-healing capabilities, was printed using slot-die coating. 36 The resulting capacitors, depicted in Figure 1b-c, were characterized extensively through multiple techniques in order to fully unveil their electronic properties before and after healing. Moreover, given that self-healing in thin films can be challenging, a detailed characterization of the materials' self-healing was performed through optical microscopy.…”

Macromolecular Bioelectronics

“…Cicoira and colleagues report on the water‐enabled self‐healing properties of poly(3,4‐ethylene‐dioxythiophene):polystyrene sulfonate (PEDOT:PSS). [ 24 ] PEDOT:PSS films processed in the presence of crosslinker, and PEDOT:PSS films post‐treated with sulfuric acid were employed to study the effect of PSS concentration on self‐healing. In comparison, PEDOT:tosylate (TOS), PEDOT:trflate (OTf), and PEDOT:ClO 4 films were prepared via electrochemical polymerization, and the effect of organic/inorganic dopants on self‐healing were investigated.…”