Synthesis and characterization of polyaniline-silica composites: Raspberry vs core-shell structures. Where do we stand?

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:502

Article

Roosz, Nicolas¹  Euvard, Myriam¹  Lakard, Boris¹  Buron, Cedric C.¹  Martin, Nicolas²  Viau, Lydie¹ 

[1] Univ Bourgogne Franche Comte, Equipe Mat & Surfaces Fonct, Inst UTINAM, CNRS,UMR 6213, 16 Route Gray, F-25030 Besancon, France

[2] Univ Bourgogne Franche Comte, Inst FEMTO ST, CNRS, UMR 6174, 15B,Ave Montboucons, F-25030 Besancon, France

关键词: Silica;    Polyaniline;    Composites;    Raspberry;    Oxidative chemical polymerization;   

DOI  :  10.1016/j.jcis.2017.04.092

来源: Elsevier

【 摘 要 】

The synthesis of polyaniline-silica composites has been reinvestigated in view of the opposing results found in the literature. Firstly, we synthesized silica particles with tunable size using the Stober process. These silica particles have been fully characterized before being used as solid support for the polymerization of aniline. This polymerization was performed according to a published procedure where the pH of the reaction mixture was below the pKa of aniline but at a value where the silica particles surface was still slightly negatively charged. The objective of this procedure was to favor electrostatic interactions between anilinium cations and the silica surface to lead to the formation of silica-polyaniline core shell particles. Several sets of nanocomposites were prepared under different experimental conditions (oxidant/aniline ratio, silica concentration, temperature, silica particles diameters). The study evidenced that under all the conditions used the formation of core-shell nanoparticles is impossible. However, using different particle sizes, noticeable morphological differences were observed. The use of large silica particles led to the formation of non-uniform polyaniline-silica composites whereas the use of smaller particles always led to raspberry-like morphology as reported by other groups in highly acidic media. The difference in morphology led to different electrical properties with electrical conductivities measured at room temperature ranging from 1.6x 10(-3) to 2.5 x 10(-5) S cm(-1). (C) 2017 Elsevier Inc. All rights reserved.

【 授权许可】

Free