Emulsion synthesis of nanoparticles containing PEDOT using conducting polymeric surfactant: Synergy for colloid stability and intercalation doping

Abstract

Poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) is a widely used conductive aqueous dispersion synthesized by using emulsion polymerization method. To further enhance its solution processability and conductivity of PEDOT derivatives, we proposed to replace the nonconductive PSS with conductive poly[2‐(3thienyl)‐ethoxy‐4‐butylsulfonate] (PTEB) as surfactant for the emulsion polymerization of PEDOT. The reaction involved colloid stabilization and doping in one step, and yielded PEDOT:PTEB composite nanoparticles with high electrical conductivity. Contrary to its counterpart containing nonconductive surfactant, PEDOT: PTEB showed increasing film conductivity with increasing PTEB concentration. The result demonstrates the formation of efficient electrical conduction network formed by the fully conductive latex nanoparticles. The addition of PTEB for EDOT polymerization significantly reduced the size of composite particles, formed stable spherical particles, enhanced thermal stability, crystallinity, and conductivity of PEDOT:PTEB composite. Evidence from UV–VIS and FTIR measurement showed that strong molecular interaction between PTEB and PEDOT resulted in the doping of PEDOT chains. X‐ray analysis further demonstrated that PTEB chains were intercalated in the layered crystal structure of PEDOT. The emulsion polymerization of EDOT using conducting surfactant, PTEB demonstrated the synergistic effect of PTEB on colloid stability and intercalation doping of PEDOT during polymerization resulting in significant conductivity improvement of PEDOT composite nanoparticles. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2536–2548, 2008

Synthesis of polydiphenylamine with tunable size and shape via emulsion polymerization

“…. There are two reasons for the increasing electrical conductivity: (1) a surfactant molecule that remains attached to the nPDPA backbone acts as a dopant molecule and electrical conductivity increases, a process known as counter‐ion‐induced doping; (2) the smaller the particle size of nPDPA, the higher the surface area for electron transfer, and thus electrical conductivity is increased . The electrical conductivity of nPDPA is quite different as each surfactant acts as a doping agent.…”

Synthesis and electrochemical capacitance of core–shell poly (3,4-ethylenedioxythiophene)/poly (sodium 4-styrenesulfonate)-modified multiwalled carbon nanotube nanocomposites

“…1b, the FT-IR of pristine PEDOT, PEDOT/CNTs (50 wt.% PEDOT) and PEDOT/PSS-CNTs (50 wt.% PEDOT) nanocomposite all show the characteristic peaks of pristine PEDOT. Notably, the vibrations at around 1336-1519 cm −1 are attribute to C-C and C C stretching of quinoidal structure and ring stretching of thiophene ring (similar to benzoidal structure) [32]. Further vibrations at about 1150 and 1000 cm −1 are both assigned to the stretching modes of the C-O-C bond, and the peak at 920 cm −1 is corresponding to the ethylenedioxy group in the molecule deformation mode [33].…”

Facile preparation of poly(3,4‐ethylenedioxythiophene) nanoparticles via a miniemulsion polymerization process

“…A gradual peak at 2θ ≈ 23.6° clearly appears in the XRD pattern, and it is assigned to the (0 2 0) reflection. The XRD pattern for PEDOT nanoparticles in general shows three peaks: 6.1–6.7° for the (1 0 0) reflection, 12.1–12.8° for the (2 0 0) reflections and 25.0–25.8° for the (0 2 0) reflection,8, 12, 13, 26 while there is a report that a single major peak assigned to the (0 2 0) reflection solely appears24 and it is in agreement with our observation. The (0 2 0) reflection peak shift to a lower angle (i.e., 25° to 23.6°) shows that the packing of the PEDOT backbone planes is loose due to insufficient p ‐doping, and thus the face‐to‐face distance between the stacked p ‐doped PEDOT sheets becomes long.…”

“…Most of research reports on the preparation of PEDOT nanoparticles have not evidently shown separate particles with clear structures and definite morphologies. The electron microscopy images of PEDOT nanoparticles published to date8, 9, 11–14, 16, 21–25, 29 show an inclination toward the aggregation of particles. The formation of irregular aggregated structures is known to be induced by π‐π stacking interactions between PEDOT nanoparticles 25.…”

“…The structure of Baytron P is known to be that the oligomeric PEDOT chains of about 6–18 repeating units are attached to the PSSA having a much longer chain length 5. Different strategies have been developed to prepare well‐defined PEDOT nanoparticles, including direct synthesis of the nanoparticles in emulsion,6–18 dispersion,19–21 and the precipitation22–31 polymerization processes. Among them, of special interest is the chemical oxidative polymerization of 3,4‐ethylenedioxythiophene (EDOT) in the presence of single‐chain schizophyllan 22, 23.…”