Characterization of poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) adsorption on cellulosic materials

Abstract

The interaction between poly(3,4-ethylene dioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) and cellulosic fibers was characterized in order to obtain further understanding of the conductivity properties of the modified cellulosic fiber material. Microcrystalline cellulose (MCC) was used as a model surface to study the adsorption behavior at various pH and salt concentrations, while samples of low-conductivity paper, normally used for the production of electrical insulation papers, were dipped into PEDOT:PSS dispersion and air-dried for X-ray photoelectron spectroscopy (XPS) studies. The results showed a strong interaction between the MCC and PEDOT:PSS, which implied a broad molecular distribution of the conducting polymer. With increasing pH, less amount of the conducting polymer was adsorbed whereas the amount adsorbed passed through a maximum value with varying salt concentration. Zeta potential measurement and polyelectrolyte titration were used to determine the surface charge of both suspended MCC particles and dispersed PEDOT:PSS at various pH levels and salt concentrations. Dip-coated paper samples exhibited two peaks in the S(2p) XPS spectra at 168-169 and 164-165 eV which correspond to the sulfur signals of sulfonate (in PSS) and in thiophene (in PEDOT), respectively. It was found that the PEDOT:PSS with a ratio of 1:2.5 was adsorbed more in the base paper than that with a ratio of 1:6. The PEDOT:PSS ratio on the surface of the cellulosic material was higher than that in the bulk liquid for all samples. The results indicated that PEDOT was preferentially adsorbed rather than PSS. The degree of washing of the conducting polymer did not significantly affect the PEDOT enhancement on the surface.

Electroconductive paper prepared by coating with blends of poly(3,4‐ethylenedioxythiophene)/poly(4‐styrenesulfonate) and organic solvents

“…A hydrophobic surface can be created by converting the outermost layer, such as a polyelectrolyte, into uncharged molecules 34. In this respect, the contact angle of the coated paper samples agrees with the earlier suggestion that there is an increase in water‐insoluble PEDOT on the outermost surface of the paper, as indicated by the X‐ray photoelectron spectroscopy analysis on PEDOT:PSS‐coated paper 35. Micro‐roughness and macro‐roughness may also affect the contact angle measurements but this has not been quantified in this study.…”

“…34 In this respect, the contact angle of the coated paper samples agrees with the earlier suggestion that there is an increase in water-insoluble PEDOT on the outermost surface of the paper, as indicated by the X-ray photoelectron spectroscopy analysis on PEDOT:PSS-coated paper. 35 Microroughness and macro-roughness may also affect the contact angle measurements but this has not been quantified in this study. Calendering the base paper before coating neither had significant effect on the contact angle of water nor did the presence of organic solvents on the coating affect the apparent contact angle, except in the case of the sample containing NMP (see Fig.…”

Integrating Electronics and Microfluidics on Paper

“…They also form electrically conducting percolation networks at lower concentrations than carbon‐black nanoparticles. Furthermore, both PEDOT:PSS and MWNT have a strong interaction with cellulose (as shown by others). They therefore form durable coatings on the cellulose fibers upon drying, and do not easily redisperse/wash away, upon wetting of the paper.…”

Tough and conductive polymer hydrogel based on double network for photo-curing 3D printing

“…In agreement with previously reported studies [29], two peaks appeared at 168.6 and 164 eV corresponded to the sulfur signals of sulfonate (in PHEA-PSS) and thiophene (in PEDOT). The peak at 168.6 eV can be decomposed into two peaks of S 2p 1/2 and S 2p 3/2 with a relative intensity ratio of 2:1 at 168.3 eV and 169.6 eV, respectively [30].…”