Surface Characterization of Polypyrrole-Coated Polystyrene Latex by X-ray Photoelectron Spectroscopy

Abstract

The surface composition of electrically conductive polypyrrole-coated polystyrene latex particles has been examined by X-ray photoelectron spectroscopy (XPS). We have systematically characterized the surface of polystyrene (PS), poly(N-vinylpyrrolidone) (PNVP), chloride-doped polypyrrole (PPyCl) powder, and PNVP-stabilized PS latex in order to determine the relative contributions of PS (core), PNVP (stabilizer), and PPyCl (shell) to the surface composition of the PPyCl-coated PS latex. XPS was found to be very effective in detecting PNVP at the surface of uncoated PS latex using N1s signal as an elemental marker and showed that the former polymer contributes to ca. 50% of the PS latex surface. In contrast, the surface composition of PPyCl-coated PS latex was found to be very PPyCl-rich, since the PPyCl bulk powder and the PPyCl-coated PS latex have very comparable XPS spectra. However, some additional iron chloride species (FeCl2 and/or FeCl3 -) were also detected as impurities at the surface of the coated latex.

Electrochemical properties of mono-particle-layer films of polyaniline-coated latex microspheres

“…Several examples of such conducting polymer-based Ôcore-shellÕ latex particles have been recently synthesized, e.g. polypyrrole-polystyrene [19][20][21][22][23][24][25], polyaniline-polystyrene [21,22,[26][27][28], and poly(3-methylthiophene)-polystyrene-polybutadiene [21]. Electrochemical measurements have been reported for suspensions of core-shell polyaniline-polystyrene latex particles [29][30][31][32].…”

Characterization methods of polymer core–shell particles

“…There are differences in electron binding energies coming from nitrogen atom in different environments. For PNVP, one signal coming from N(1s) is observed in the spectrum, whereas polypyrrole is described by four signals located in the range of 396-406 eV with peaks at 398-399, 400-401, 402-403 and 403-404 eV, which are attributed to the N=C, N-H bonds and the two high oxidation states of nitrogen (N I ox and N II ox ) in doped polypyrrole [39]. Quantitative analysis can be performed for a two-component surface provided that at least one type of element is different in each compound.…”

“…However, heteroatoms and halogens cause the binding energy increase. For example, in an XPS spectrum of poly(N-vinylpyrrolidone) (PNVP), binding energy values of 285.9 and 287.7 eV correspond to carbon atoms in C-N and N-C=O groups, respectively [39]. A characteristic of polystyrene is a low-intensity feature at 291.7 eV because of the C(1s) π−π * shake-up satellite.…”

Conducting Polymer-Coated Latex Particles

“…Our initial XPS studies confirmed that PPY forms a very uniform overlayer on micrometer-sized PS latexes, with a surface coverage of 94±100 %. [19] In contrast, Barthet et al…”