Thermal conversion of poly(paraphenylene-vinylene) precursor films: XPS and ESR studies

Abstract

The conversion of the precursor into poly(phenylene–vinylene) (PPV) was studied by means of photoelectron spectroscopy (XPS) and electron spin resonance (ESR) on precursor films synthesized from the polymerization of pxylene‐tetrahydrophenium halides. The sulfonium precursor containing chlorine or bromine was thermally converted to PPV and analyzed in situ using the spectrometers. It was found by XPS analysis that both halide precursors were thermally converted into polymer in a range of 190–250°C but traces of bromine were still present at >300 °C in the precursor containing Br. Furthermore, a small amount of oxygen in a ketone structure was also present in fully converted films. The ESR results corroborated the XPS experiments, showing a progressive disappearance of the radical distribution related to sulfur sites in a comparable temperature range. A discussion of the conversion process is given in terms of the modification of the core level spectra from XPS and the g distributions from ESR experiments. © 1997 John Wiley & Sons, Ltd.

Surface modification of silica nanoparticles with hydrophilic polymers

“…For SiO 2 -g-POEM nanoparticles, the binding energy of C 1s was deconvoluted into the CH 2 /CH 3 groups at 284.6 eV, the C carbon at 286.0 eV, the COO groups at 286.03 eV and the COC group at 288.4 eV, respectively. The C 1s narrow scan spectrum of SiO 2 -PSSA was also curve-fitted with three peak components having binding energy at about 284.3, 284.6 and 287.3 eV, attributable to the aromatic C, CH 2 /CH 3 and C-SO 3 À Na + species of PSSA, respectively [30,[39][40][41]. Fig.…”

A Method for Fabricating an Ultrathin Multilayer Film Composed of Poly(p‐phenylenevinylene) and Reduced Graphene Oxide on a Plastic Substrate for Flexible Optoelectronic Applications

“…Deconvolution of O 1s peak (Figure S4b, Supporting Information) showed three peaks corresponding to C=O/O‐C=O (530.7 eV), C‐O (531.9 eV), and H 2 O (533.3 eV), which corresponded to various oxygenated GO functional groups 42. Deconvolution of S 2p peak (Figure S4c, Supporting Information) revealed two peaks at S 2p 3/2 (162.8 eV) and S 2p 1/2 (165.5 eV), which were ascribed to peaks characteristic of tetrahydrothiophenium group 43…”

Study on the effect of acid‐ or iodine‐doping on the properties of copolymer C1–4poly‐phenylene‐vinylene‐ether

“…In fact, the g value observed for PPV radical or the radical created by irradiation in organic acid (essentially protonation of the double bond) ranged from 2.0025 to 2.0038. 11, 22–25 Moreover, all these radicals were located on carbon atoms. In the case of organic acid, the unpaired electron was expected to reside chiefly in a π (2p z ) state on the carbon atom of the carboxyl group where the z direction is normal to the plane of the group.…”

“…1 Consequently, PPV and its derivatives remain suitable candidates for flexible large‐area display technology based on polymer light‐ emitting diodes (PLEDs). 2–11 In parallel, a number of investigations were undertaken to ameliorate the properties of organic semiconducting polymers by doping. Therefore, much work was carried out to discover new dopants and doping techniques.…”