Polymeric materials, core electron

Introduction to Core Electron Spectra of Polymeric Materials... [Pg.145]

In recent years, positron annihilation lifetime (PAL) spectroscopy has been demonstrated to be a special sub-nanometer probe to determine the free-volume hole size, fraction and distribution in a variety of polymers (4-9). In this technique, measured lifetimes and relative intensities of the positron and positronium, Ps (a bound atom which consists of an electron and a positron), are related to the size and fraction of sub-nanometer holes in polymeric materials. Because of the positive-charge nature, the positron and Ps are repelled by the ion core of polymer molecules and trapped in open spaces, such as holes, free volumes, and voids. The observed... [Pg.355]

In this section the identification of various structural features from the measured binding energies of the core level electrons is discussed. Examples have been chosen in the areas of (a) plasma polymerization of fluorinated materials and (b) surface oxidation of polymers, to encompass both fluorine-containing and oxygen-containing systems. [Pg.302]

Several reports related to PEDOT-coated particles and PEDOT hollow particles have been pronounced in the literature [359,360]. Dispersion polymerization has been applied for PEDOT-coated PS particles fabrication. 100 nm PS nanoparticle was used as the core material [359]. hi order to improve the stability of the PS particle, DBSA was used as the surfactant. It was presumed that hydrophobic alkyl chains of the surfactant were positioned towards the surface of PS particles and the sulfonic acid group toward the water phase. EDOT monomer was adsorbed on the surface of the PS nanosphere and polymerization was initiated by the addition of the APS oxidant. PS-PEDOT core-shell structure was distinctively visualized by TEM. The doped PEDOT shell had a higher electron density than the PS core and the thickness of the PEDOT shell was ca. 8 nm. [Pg.231]

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