Nanocomposite of Polyaniline and Na⁺−Montmorillonite Clay

Abstract

Nanocomposites of conducting polyaniline (PAN) with inorganic Na + -montmorillonite (MMT) clay were synthesized by the emulsion polymerization method. The dodecylbenzenesulfonic acid (DBSA) was used for both dopant and emulsifier. Analyses of X-ray diffraction patterns demonstrated that conducting PAN-DBSA was intercalated between inorganic clay layers at the nanoscale level (<10 Å). We observed that the clay induced more disordered state in PAN-DBSA/clay nanocomposites. From the temperature-dependent dc conductivity [σ dc(T)] experiments, we investigated charge transport mechanism of the PAN-DBSA and PAN-DBSA/clay systems. The interaction between the intercalated PAN-DBSA and the clay layers was observed by FT-IR spectra. The results of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed the improved thermal stability of the nanocomposite materials. The σ dc of these systems was 10 1 -10 -2 S/cm at room temperature, varying with dopant molar ratio. The σdc(T) of the nanocomposite of PAN-DBSA/clay was represented by the quasi-one-dimensional variable range hopping model. From electron paramagnetic resonance experiments, magnetic susceptibility was obtained for the systems. We discuss the effects of the intercalation and clay on charge transport, structural, and thermal properties for PAN-DBSA/clay nanocomposites.

Spectroscopic, morphological and electrochromic characterization of layer-by-layer hybrid films of polyaniline and hexaniobate nanoscrolls

“…[44][45][46][47][48][49] Hybrid electrochromic films based on NiO and polyaniline (PANI) have shown fast operation, high stability and a remarkable efficiency of 85 cm 2 C…”

Polyaniline: Thin films and colloidal dispersions (IUPAC Technical Report)

“…The powders of inorganic oxides, like silicon dioxide [40,41], titanium dioxide [42], copper(II) oxide [43], and ferrites [44], may serve as examples of another group of materials which have been modified on the surface with PANI. Special attention has been paid to montmorillonite and related clays [45][46][47][48]. The applications of surface-modified substrates range from sensors and electronic noses [18,49], electrodes [30,50], conducting fillers [51], electro-rheological suspensions [42,48,52], corrosion protection [45], gas-separation membranes [29], and catalysis of organic reactions [53] to electromagnetic interference shielding [34] or increasing the dielectric breakdown of polymer films [28].…”

Structural changes of polyaniline/montmorillonite nanocomposites and their effects on physical properties

“…After the observation of PANI intercalation into Cu 21 exchanged silicates by Cloos et al in 1979, 19 a number of studies on the preparation, properties and applications of PANI/layered silicate nanocomposites were carried out. [10][11][12][13][14][20][21][22][23][24][25][26][27][28] Most recently, Yang and Chen reported the synthesis of PANI/ organically modified clay nanocomposites and found that more PANI chains are formed between interlayer spacings of the modified clay, especially for HOOC(CH 2 ) 11 NH 3 1 modified clay because the acidic HOOC(CH 2 ) 11 NH 3 1 ions residing between interlayer spacings provide a stronger driving force for the intercalation of aniline monomer. 29 Yeh et al reported that regardless of clay content, the synthesis of PANI/clay nanocomposites with exfoliated silicate layers of clay was realized and they investigated the effect of such nanocomposites on the corrosion protection of cold rolled steel (CRS) when compared with that of an emeraldine base of PANI using a series of electrochemical measurements of corrosion potential and polarization resistance.…”