Synthesis, Characterization, and Electrokinetic Properties of Polyindene/Colemanite Conducting Composite

Abstract

The aim of the aqueous electrokinetic experiments in the present study was to assess the relative contribution of the conducting polyindene (PIn) and inorganic colemanite components to the zeta (ζ) potentials of the composite particles, thus providing further insight into their surface composition in the dispersed state and establishing colloidally stable conditions for potential rheological, industrial applications. For this, PIn and a PIn/colemanite composite (containing 5 wt.% colemanite) were synthesized by chemical oxidative polymerization using FeCl3 as an oxidizing agent. Colemanite, PIn, and PIn/colemanite composite samples were characterized by Fourier-transform infrared spectroscopy, elemental analysis, conductivity, dielectric constant, magnetic susceptibility, density, particle-size measurements, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction analysis, and scanning electron microscopy methods. The electrokinetic properties of colemanite and PIn/colemanite composite dispersions were determined by ζ-potential measurements in aqueous medium, taking into account the effects of time, pH, various electrolytes, surfactants, and temperature. The pH was observed to have a greater effect on the ζ potentials of colemanite in water but caused only slight changes in the presence of cationic (NaCl, BaCl2, AlCl3) and anionic (NaCl, Na2SO4) electrolytes. Increased pH values shifted the ζ potentials of PIn/colemanite composite dispersions to more negative values. The most effective surfactant acting on the ζ potentials of colemanite and PIn/colemanite composite dispersions was cetyltrimethylammonium bromide (CTAB), which shifted the ζ potentials to more positive regions. Elevated temperatures caused almost no change to the ζ potentials of either the colemanite or the PIn/colemanite composite dispersions.

The negative and positive electrorheological behavior and vibration damping characteristics of colemanite and polyindene/colemanite conducting composite

“…It should be noted that a proper conductivity range for the dispersed particles is important for an ERF [26]. The conductivities (σ ) of the materials examined in this study were as follows: σ PIn = 1.85 × 10 −4 S cm −1 < σ PIn/colemanite = 2.48 × 10 −4 S cm −1 < σ colemanite = 3.14 × 10 −4 S cm −1 [18]. It was concluded that the relatively high conductivities may also contribute to cause the negative ER response of the colemanite and PIn/colemanite composite systems.…”

“…The PIn was polymerized in situ in the presence of colemanite using FeCl 3 as an oxidizing agent taking the monomer to initiator ratio as 2:1 in CHCl 3 and the obtained PIn/colemanite composite was subjected to various characterization techniques, namely FTIR, particle size, magnetic susceptibility, density, conductivity, dielectric, TGA/DSC, XRD, SEM and ζ -potential measurements. The full details of the synthesis and characterization of the PIn and PIn/colemanite composite are given in our previous publication [18].…”