Synthesis, D.C. Electrical Conductivity and Activation Energy of Metal Sulphides Doped Polyaniline-Nanocomposite

Introduction

Nanotechnology is a supportive application in all fields of the research area in modern science. It possesses different shapes and sizes ranging from 1 nm to 100 nm [1]. Polymeric nanocomposites consisting of organic polymer and inorganic nanoparticles in a nanoscale regime represent a novel class of materials that have motivated considerable interest in recent years. These composites exhibit new advantageous properties and can be very different from those of their individual counterparts. It is therefore expected that this type of materials will play increasingly important roles in research and in numerous applications. They normally have particular properties and are important for many technological applications, ranging from microelectronics to catalysis, optoelectronic devices, and synthesis of lubricant and preparation of electrolytes for rechargeable batteries [1-4]. Polyaniline (PANI) is one of the most interesting conducting polymers due to its low cost, good processibility, environmental stability, unique active conduction mechanism [5] and reversible control of conductivity both by charge-transfer doping and protonation [6]. Inorganic semiconductors CdS, ZnS & PbS nanoparticles are the most promising materials used in various applications like sensors, optoelectronic devices and in solar cells. Studies on PANI-CdS nanocomposites have been reported by many researchers [7-10] and focused on electrical conductivity. This paper presents the synthesis and d.c. electrical conductivity of PANI-CdS and PANI-Pbs nanocomposites.

Materials and Methods

All chemicals used in this investigation were of analytical reagent grade and used as received. Only aniline was distilled prior to use.

Synthesis of Polyaniline via chemical oxidative polymerization

Polymerization was dispensed by the chemical oxidization of aminoalkane within the presence of H2SO4 and APS (Ammonium per-sulphate) in 100 ml water each contend the role as dopant and oxidizing agent severally. (0.4 mol) APS was dissolved in 100 ml water during a four-neck spherical bottom reaction flask and zero.4 mol H2SO4 is additionally another underneath involuntary stirring for two hours. Aniline (0.4 mol) was stirred with zero.4 mol of H2SO4 in 100 ml water. The solution of APS in H2SO4 was then added drop-wise within the solution of aminoalkane with vigorous stirring on a magnetic stirrer for three hours to initiate the aminoalkane chemical process. The reaction was later dispensed at temperature for 6-7 hours with stirring. A dark inexperienced coloured PANI suspension was obtained with precipitation. The synthesized PANI washed with deionized water repeatedly till the liquid was fully colorless. Finally, the mixture was filtered by filtered assembly. A precipitate of polyaniline was dried at 60ºC to 800ºC in oven.

Characterizations

X-RD spectra of all samples were taken on Philips PW -3071, Automatic X-ray diffractometer using Cu-Kα radiation of wavelength 1.544 Å, continuous scan of 2ºC min., with an accuracy of 0.01 at 45 KV and 40 mA. Fourier Transform Infra-Red (FTIR) spectroscopy (Model: Perkin Elmer 100) of PAni: Cds nanocomposite was studied in the frequency range of 400 cm^-1-4000 cm^-1.

TGA thermograms of all samples were recorded on Perkin- Elmer Diamond TGA/DTA in argon atmosphere at a heating rate of 10°C/min. TGA profile were taken over the temperature range of 30°C-1000°C.The electrical conductivity measurement were made using four probe techniques.

Conclusions

In general, Polyaniline nanocomposites of different weight percentages of Cds were synthesized in a simple and eco-friendly route of chemical oxidation. The different CdS/PANI based composites were developed. The following FT-IR, XRD and TEM, also been done. Further, D.C.electrical conductivity and activation energy has also been studied. In general, PAni/CdS surface-treated nanocomposite properties were found to be excellent overall, compared to the untreated ones. Improved Electrical conductivity at different weight percentages of CdS was examined. The present investigation clear the Electrical conductivity could also be potential for industrial application when they are surface modified.

References

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