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

Abstract

Polyaniline/montmorillonite (MMT) nanocomposites containing different PANI contents were prepared by the intercalation of aniline monomer into pristine MMT followed by the subsequent oxidative polymerization of the aniline in the interlayer spacings. The polyaniline/MMT nanocomposite structure intercalated with polyaniline (PANI) was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). From the full-width at half-maximum (FWHM) of the (001) reflection peaks in the XRD patterns, the PANI/ MMT nanocomposite containing 12.3 wt% PANI (PMN12) was found to be in the most disordered state. The physical interaction between the intercalated PANI and the basal surfaces of MMT was monitored by FT-IR. The room-temperature conductivity (s RT ) varied from 9.1 6 10 29 to 1.5 6 10 0 S cm 21 depending on the PANI content in the nanocomposites. The temperature dependence of dc conductivity (s dc (T)) of all the samples follows the quasi-1D variable range hopping (quasi-1D VRH) model (i.e., s dc (T) 3 exp [2(T 0 /T) 1/2 ]). The charge transport behavior of this system was interpreted from the slopes (T 0 ) of the s dc curves and the highest T 0 value was found for the PANI/MMT nanocomposite with 12.3 wt% PANI (PMN12). The FT-IR, s dc (T) and s RT results for the nanocomposites with varying content of PANI are consistently related to the structure of the PANI/MMT nanocomposites discussed in the XRD analysis. The structural argument was further supported by scanning electron microscopy (SEM) of all the samples. Thermogravimetric analysis (TGA) showed improved thermal stability for the intercalated nanocomposites in comparison with the pure PANI and a simple PANI/MMT mixture.

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…”

Synthesis, Characterization and Studies of PANI-MMT Nanocompoisites

“…The chemistry of functionalized poly mers, copolymers and nanoclay composites has attracted greater attention of material scientists and organic chemists in recent times. Clay minerals have been adopted to the field of nanocomposites because of their ultrafine particle size, large surface area and intercalation property in applications such as reinforcement materials with poly mers, oil and natural gas separation and extraction, electronic noses and other application devices, particularly, co mposites of polyaniline and Montomorillonite (MMT)/Bentonite (BT) are potential fillers for the modification of the mechanical and conducting properties of poly mer matrices [8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”

Synthesis and Surface Observation of Montmorillonite/Polyaniline Composites

“…The small distance may be due to the formation of the molecular layer of PANI in the interlayer of Mt. [7,8]. The signal at 6.2 • could also cause the formation of a hollow nano-tube [18,19] with good PANI aggregation [20].…”

“…Mt is an interesting inorganic clay. Mt consists of layered silicates with negative charges [7,8]. The multiple layers absorb water and organic compounds.…”