Preparation and characterisation of novel polypyrrole–silica colloidal nanocomposites

We describe the preparation and characterisation of colloidal dispersions of polypyrrole–silica nanocomposite particles. These nanocomposites have been characterised in terms of their particle size and chemical composition by a wide range of experimental techniques, including transmission electron microscopy, disc centrifuge photosedimentometry, photon correlation spectroscopy, elemental microanalyses, thermogravimetry, infrared spectroscopy and dc solid-state conductivity measurements. We find that both the particle size and the chemical composition depend markedly on the type of chemical oxidant selected for the in situ polymerisation of the pyrrole monomer. For example, using the FeCl3 oxidant we obtain polypyrrole–silica particles which contain up to 70 m/m% polypyrrole and have particle diameters in the range 160–320 nm, whereas the (NH4)2S2O8 oxidant yields composite particles which contain only 37–55 m/m% polypyrrole and are ca. 110–180 nm in diameter. In most cases the particle size distributions are reasonably narrow, with standard deviations as low as 13% as measured by disc centrifuge photosedimentometry. We have also investigated the mechanism of formation of these nanocomposite particles by studying: (i) the adsorption of pyrrole monomer from aqueous solution onto colloidal silica; (ii) the adsorption of oxidant [either FeCl3 or (NH4)2S2O8] from aqueous solution onto colloidal silica. These adsorption studies indicate that either the monomer or the oxidant is partially adsorbed onto the silica particles prior to polymerisation in all of our syntheses. Thus, surface polymerisation processes may be important in the formation of these nanocomposite particles.

[1]  S. Armes,et al.  Small-angle x-ray scattering studies on colloidal dispersions of polyaniline-silica nanocomposites , 1993 .

[2]  S. Armes,et al.  PREPARATION OF NOVEL POLYPYRROLE-SILICA COLLOIDAL NANOCOMPOSITES , 1993 .

[3]  U. Suter,et al.  High refractive index films of polymer nanocomposites , 1993 .

[4]  Yen Wei,et al.  Synthesis, characterization, and properties of new polystyrene-SiO_2 hybrid sol-gel materials , 1993 .

[5]  Yen Wei,et al.  Synthesis of new polyacrylonitrile‐silica hybrid sol‐gel materials and their thermal properties , 1993 .

[6]  S. Armes,et al.  Some observations on the preparation of colloidal polyaniline - silica composites , 1993 .

[7]  S. Armes,et al.  Colloidal dispersions of surfactant-stabilized polypyrrole particles , 1993 .

[8]  P. Prasad,et al.  Characterization of sol-gel processed poly(p-phenylenevinylene) silica and V2O5 composites using waveguide Raman, Raman and FTi.r. spectroscopy , 1993 .

[9]  K. Chao,et al.  Intercalation and oxidative polymerization of aniline in zirconium phosphates , 1993 .

[10]  T. Saegusa,et al.  Structure of poly(vinylpyrrolidone)-silica hybrid , 1992 .

[11]  Hong Xu,et al.  Evolution of Physical and Electrochemical Properties of Polypyrrole during Extended Oxidation , 1992 .

[12]  Steven P. Armes,et al.  Particle size distributions of polyaniline-silica colloidal composites , 1992 .

[13]  K. Yoshinaga,et al.  Preparation of monodispersed polymer-modified silica particles by radical polymerization using silica colloid and introduction of functional groups on the composite surface , 1992 .

[14]  S. Armes,et al.  Synthesis of novel polyaniline colloids using chemically grafted poly(N-vinylpyrrolidone)-based stabilizers , 1992 .

[15]  S. Armes,et al.  Preparation and characterisation of polyaniline colloids using a monodisperse poly(ethylene oxide)-based steric stabiliser , 1992 .

[16]  N. Gospodinova,et al.  Stable aqueous dispersions of polyaniline , 1992 .

[17]  S. Armes,et al.  Novel colloidal polyaniline–silica composites , 1992 .

[18]  M. Digar,et al.  Conducting polypyrrole particles dispersible in both aqueous and non-aqueous media , 1992 .

[19]  V. Mehrotra,et al.  Electrically conducting glasses: incorporation of polypyrrole in a porous SiO2 matrix , 1991 .

[20]  H. S. Lee,et al.  An Electrochemical and Optical Investigation of Polypyrrole/Polyethyleneoxide Latex Particles , 1991 .

[21]  Jia-Ming Liu,et al.  Novel colloidal polyaniline fibrils made by template guided chemical polymerization , 1991 .

[22]  S. Kuwabata,et al.  Charge–discharge properties of polypyrrole films containing manganese dioxide particles , 1991 .

[23]  S. Armes,et al.  Aqueous colloidal dispersions of polyaniline formed by using poly(vinylpyridine)-based steric stabilizers , 1990 .

[24]  H. Yoneyama,et al.  Incorporation of WO 3 into Polypyrrole, and Electrochemical Properties of the Resulting Polymer Films , 1990 .

[25]  S. Armes,et al.  Synthesis and characterization of aqueous colloidal dispersions of poly(vinyl alcohol)/polyaniline particles , 1990 .

[26]  S. Kuwabata,et al.  Electrochemical Synthesis of Polypyrrole Films Containing TiO2 Powder Particles , 1990 .

[27]  F. Henry,et al.  Chemical synthesis and dielectric characterisation in microwave domain of polypyrrole latexes , 1990 .

[28]  S. Armes,et al.  Preparation and characterization of colloidal dispersions of polypyrrole using poly(2-vinyl pyridine)-based steric stabilizers , 1990 .

[29]  B. Vincent,et al.  Colloidal dispersions of electrically-conducting, spherical polyaniline particles , 1990 .

[30]  M. Kanatzidis,et al.  Conductive polymer bronzes. Intercalated polyaniline in V2O5 xerogels , 1989 .

[31]  S. Armes,et al.  Novel colloidal dispersons of polyaniline , 1989 .

[32]  B. Vincent,et al.  Colloidal dispersions of electrically conducting polypyrrole particles in various media , 1988 .

[33]  G. Wegner,et al.  Electrochemistry of thin polypyrrole films , 1987 .

[34]  S. Dong,et al.  Study on polypyrrole film by electrochemical polymerization in aqueous solution , 1987 .

[35]  R. Bjorklund.  Kinetics of pyrrole polymerisation in aqueous iron chloride solution , 1987 .

[36]  B. Vincent,et al.  Dispersions of electrically conducting polypyrrole particles in aqueous media , 1987 .

[37]  B. Liedberg,et al.  Electrically conducting composites of colloidal polypyrrole and methylcellulose , 1986 .

[38]  K. Khulbe,et al.  Polymerization of pyrrole by potassium persulfate , 1982 .

[39]  J. G. Vandusen,et al.  Phenol end-capped polystyrene. A polymeric reagent for the synthesis of branched polymers , 1980 .

[40]  R. Iler.  The Chemistry of Silica: Solubility, Polymerization, Colloid and Surface Properties and Biochemistry of Silica , 1979 .

[41]  P. Elkington,et al.  Hydrogen bonding and adsorption on silica gel , 1968 .

[42]  F. Palilla,et al.  Determination of Iron by Ultraviolet Spectrophotometry , 1956 .