Combining Step‐Growth and Chain‐Growth Polymerizations in One Pot: Light‐Induced Fabrication of Conductive Nanoporous PEDOT‐PCL Scaffold

Abstract

A novel method based on light‐induced fabrication of a poly (3,4‐ethylenedioxythiophene)‐polycaprolactone (PEDOT‐PCL) scaffold using phenacyl bromide (PAB) as a single‐component photoinitiator is presented. HBr released from the step‐growth polymerization of EDOT is utilized as an in situ catalyst for the chain‐growth polymerization of ε‐caprolactone. Detailed investigations disclose the formation of a self‐assembled nanoporous electroconductive scaffold (1.2 mS cm−1). Fluorescence emission spectra of the fabricated scaffold exhibit a mixed solvatochromic behavior, indicating specific interactions between the self‐assembled scaffold and solvents with varying polarities, as evidenced by transmission electron microscopy (TEM). Moreover, the same light‐induced technique can also be applied for bulk photopolymerization showcasing the versatility and wide‐ranging scope of the originated method. In brief, this study introduces a novel approach for light‐induced polymerization reactions that is merging step‐growth and chain‐growth mechanisms. This innovative approach is promising to facilitate in situ polymerization of monomers possessing diverse functionalities.

Black-to-Transmissive Electrochromic Switching PEDOT-co-poly(N-ethylcarbazole) via a Sustainable and Facile In Situ Photo(co)polymerization Method

“…79−84 More recently, the random copolymerization using equimolar amounts of EDOT and ε-caprolactone monomers demonstrated the possibility of employing PAB as a singlecomponent photoinitiating system for the light-induced copolymerization reactions. 77 For the photo(co)polymerization attempt of EDOT-ECz monomers, a similar reaction procedure was applied. 77 For a better understanding and comparison, homopolymers of EDOT and ECz (PEDOT and PECz) were also separately synthesized using the same photoinitiating system under identical conditions.…”

“…77 For the photo(co)polymerization attempt of EDOT-ECz monomers, a similar reaction procedure was applied. 77 For a better understanding and comparison, homopolymers of EDOT and ECz (PEDOT and PECz) were also separately synthesized using the same photoinitiating system under identical conditions. Photos of the resultant polymer powders can be found in the Supporting Information (Figure S1).…”

“…Previous water contact angle measurements have revealed the weak hydrophilic nature of photochemically generated PEDOT, which was attributed to the ion−dipole interactions between dopant ions (bromide) and surrounding water molecules (atmospheric humidity). 77 Most importantly, there are significant changes between the fingerprint regions of PEDOT and PEDOT-co-PECz spectra; peaks between 980 and 680 cm −1 in PEDOT corresponding to C−S stretching vibrations exhibit ∼20 cm −1 shifts in the spectrum of PEDOTco-PECz. Similar shifts can also be observed for the C−O−C stretching vibrations at around 1380 cm −1 .…”

“…76 Very recently, our group successfully obtained a PEDOT-polycaprolactone scaffold by a newly developed light-induced methodology, which employed phenacyl bromide (PAB) as both a photooxidant and an acid generator. 77 Taking into consideration all of the previous works and the close oxidation potentials of ECz and EDOT monomers, 61 we envisioned in the present study the light-induced in situ copolymerization of ECz and EDOT, using PAB as a singlecomponent photoinitiating system under UVA light and inert atmosphere in a step-growth manner (Figure 1d). We employed the photopolymerization in an acetonitrile (ACN) solvent, which can be regarded safer when compared to halogenated solvents.…”

“…In the context of sustainability, light-induced polymerization (photopolymerization) techniques are promising alternatives to (electro)­chemical polymerization methods due to their lower energy requirements, milder conditions, and lower costs. − Particularly, the possibility of spatiotemporal control makes photopolymerization techniques more favorable over the conventional methods. , Spatiotemporal control can lead to the ECMs possessing sophisticated architecture through different 3D printing technologies, including vat photopolymerization . Very recently, our group successfully obtained a PEDOT-polycaprolactone scaffold by a newly developed light-induced methodology, which employed phenacyl bromide (PAB) as both a photooxidant and an acid generator …”