We have examined the properties of electrodeposited poly(2'-maleimideomethyl-3,4-ethylenedioxythiophene) (PEDOT-MA) and compared it to pristine poly(3,4-ethylenedioxythiophene) (PEDOT). According to results of linear cyclic voltammetry (linear CV) and galvanostatic charging/discharging (GCD) in 0.1 M KCl aqueous solution, PEDOT-MA presented higher areal specific capacitance, 5.8×10-3 F/cm2 at 25 mV/s and 7.0×10-3 F/cm2 at 1.6×10-4 A/cm2, while PEDOT, electrodeposited at the same charge densities, only exhibited 5.4×10-3 F/cm2 at 25 mV/s and 6.3×10-3 F/cm2 at 1.6×10-4 A/cm2. The effective Young's modulus was evaluated by nanoindentation and that value for PEDOT-MA was 4.5 GPa, while it was 1.8 GPa for PEDOT. PEDOT-MA showed decreased scattering from the lamellar stacking ~1.21 nm and π-π stacking ~0.34 nm as confirmed by grazing-incidence wide-angle X-ray scattering (GIWAXS). However, the impedance performance across a broad range of frequencies (10-1 to 105 Hz) was similar for both PEDOT and PEDOT-MA, indicating that both materials remained effective at charge transport. Accessibilities and availabilities of the maleimide functionalities were also evaluated by attaching thiol-cholesterol moieties through click chemistry. Both the increased contact angle from PEDOT-MA (25°) to thiol-cholesterol post-processed PEDOT-MA (115°) and the suppressed linear CV response reflected the successful attachment of cholesterol functionalities on the material surface under mild conditions (room temperature and pressure). The gradual increase of the impedance amplitude with the increasing immersion time in thiol-cholesterol solution was also studied to show the possibility of sensing the concentration of analytes based on the alteration of impedance at a certain frequency. Our work has offered a route to post-process PEDOT with biologically-derived functionalities that have precisely tailored charge transport properties.

Structure and properties characterization of poly(2-maleimideomethyl-3,4-ethylenedioxythiophene) (PEDOT-MA)

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.