Syntehesis, characterization and electrorheological properties of polyindole/montmorillonite nanocomposite

In this study, first polyindole (PIN) was synthesized using FeCl3 as an oxidizing agent. Then, an organo-montmorillonite (O-MMT) was prepared from virgin montmorillonite (MMT) by cetiltrimethylammonium bromide (CTMAB) quaternary ammonium salt. Further, PIN/O-MMT nanocomposite was prepared with 18% O-MMT content. The samples of PIN, MMT, O-MMT and PIN/O-MMT nanocomposite were characterized by FTIR spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (X-RD), elemental analysis, conductivity, dielectric measurements, magnetic susceptibility, density, particle size measurements and scanning electron microscopy (SEM) method. Characterization results showed a successfully prepared PIN/O-MMT nanocomposite having both intercalated and exfoliated structures. A series of concentrations (5-25%, m/m) were prepared from those above mentioned materials in silicone oil (SO) and their sedimentation stabilities determined. The suspensions were subjected to an external electric field strength and electrorheological (ER) activity observed. The effects of dispersed particle concentration, shear rate, external electric field strength, frequency and temperature onto ER activities of these suspensions were investigated. Creep tests were applied to all the four suspensions and recoverable viscoelastic deformations observed.