Electrochromic pattern formation by photo cross-linking reaction of PEDOT side chains

Abstract

An electrochemically and photochemically polymerizable monomer, 2- ((2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methoxy)ethyl methacrylate (EDOT-EMA), was explored for patterning of poly(3,4-ethylenedioxythiophene) (PEDOT) via side chain cross-linking. The polymer from EDOT-EMA was deposited electrochemically to produce polymeric EDOT (PEDOT-EMA), which was directly photo-patterned by UV light as the side EMA groups of PEDOT-EMA were polymerized to give cross-linked EMA (PEDOT-PEMA). Absorption and FTIR studies of the UV-exposed film (PEDOT-PEMA) indicated that the photo-patterning mainly originated from the photo cross-linking of the methacrylates in the side-chain. After irradiation of the film, the conductivity of the irradiated area decreased from 5.6×10 -3 S/cm to 7.2×10 -4S/cm, possibly due to bending of the conductive PEDOT channel as a result of the side chain cross-linking. The patterned film was applied to a solid state electrochromic (EC) cell to obtain micro-patterned EC cells with lines up to 5 μm wide.

Redox-Active Polymers for Energy Storage Nanoarchitectonics

“…It is a well-known characteristic that conducting polymers have a reversible (or switchable) absorption property in the UV/visible/near infrared (UV/Vis-NIR) region of the spectrum according to their doping state. 36,76,81 The UV/Vis-NIR spectroelectrochemistry of ELi thin films on platinum revealed a broad long-tail absorption extending into the infrared for the intermediate and higher oxidation states of ELi, LiPNB, which is due to doped highly delocalized charges along the backbone, as seen in Figure 3E. On the other hand, the completely reduced state, lithium pernigraniline (PNLi), shows no absorption in the visible-NIR region as would be expected of an insulating material, the same as for LE.…”

Microscale Patterning of Electrochromic Polymer Films via Soft Lithography

“…Various classes of materials including transition metal oxides and conducting polymers have been widely studied as promising EC materials thus far [6][7][8][9]. In particular, considerable research efforts have been devoted to the EC behaviors of conducting polymers owing to their outstanding advantages of low cost, mechanical flexibility, and solution processability in comparison with inorganic materials [10][11][12][13][14][15].…”

“…For practical applications of EC devices, patterning processes of the EC layers in thin-film form are necessarily required in accordance with their intended uses [10][11][12][13][14][15][16]. However, conventional patterning processes such as photolithography and shadow mask deposition are mostly inappropriate for conducting polymers because the polymers are significantly damaged or even broken down under harsh processing conditions involved in etching or physical vapor deposition [17].…”

A Triazine Bridged <I>p</I>-Phenylenevinylene Polymer Film for Biomolecular Patterning

“…1 A lot of ways have been developed to make polymeric patterns with micrometer and submicrometer scale, such as direct writing of polymer patterns via laser ablation, soft-lithographic methods, the use of photo-or electrochemically-polymerizable precursors, and electric fieldinduced patterning of block copolymers, and holographic recording method. [2][3][4][5][6][7][8][9][10][11] Generally, control over spatial structure at defined positions on biomaterial substrates is essential for tissue engineering, biosensor technology, assay applications, and for fundamental studies in cell biology. 2 12-13 In order to pattern the biomaterials, many techniques have been developed including plasmabased dry etching methods to pattern cell cultures inside microfluidic devices, template-based approaches using self-assembled monolayers patterned with low energy electrons, direct patterning of proteins by microcontact printing onto mixed self-assembled monolayers, and nanoscale protein patterning by imprint lithography.…”