In the present work, we report on effect of camphor sulfonic acid (CSA) doping on polyaniline-ZnO (50%) nanocomposites prepared by spin coating method on glass substrates. The XRD analysis revealed that the addition of CSA has no effect on crystallinity of PANi-ZnO nanocomposites. Surface morphological studies (SEM) showed that CSA has a strong effect on morphology of PANi-ZnO. The FTIR & UV-Vis spectroscopy confirmed the interaction between CSA and PANi-ZnO nanocomposite. DC electrical conductivity studies showed an increase in conductivity of PANi-ZnO nanocomposites by one order due to addition of CSA (10% - 50%).
Semiconducting zinc oxide (ZnO) is attracting lot of attention due to its unique properties such as direct wide band gap (3.37 eV) and large exciton binding energy (60 meV) at room temperature [
In recent years, the development of inorganic/polymer hybrid materials on nanometer scale have been receiving significant attention due to a wide range of potential applications in optoelectronic devices [11-13] and in field effect transistors [
In most of these cases, the nanocomposites were further used in various applications in their thin-film form. Although these PANi-ZnO nanocomposites are also conducting since they are polyaniline emeraldine chloride, their processability is still poor to limit their commercial uses although their conductivity could be measured by sandwiching the pellets. PANi doped with organic acids such as CSA, DBSA, PVSA etc. which possesses sufficiently strong Bronsted acid centers capable of polyaniline protonation together with suitable functional groups which, when introduced to the polymer matrix upon doping, induce the solubilization of its stiff conjugated backbone, is readily soluble, chemically stable, and electrically conductive [24-27].
There are few reports on the synthesis, morphological, electrical and optical studies [28,29] of PANi/ZnO composite. However to the best of our knowledge no study has been reported on effect of organic (ionic) acid doping on PANi/ZnO nanocomposite.
In this paper for the first time, we report systematic investigation on the effect of camphor sulfonic acid (CSA) doping on structural, morphological optical and electrical properties of PANi-ZnO nanocomposite. Much effort has been put into the investigation of the interaction between CSA and PANi-ZnO in order to gain a better understanding of the doping effect of CSA. The structural, morphological, optical and electrical properties of CSA doped PANi-ZnO nanocomposite were investigated using XRD, FTIR, SEM, UV-Vis spectroscopy and four probe technique.
The undoped polyaniline powder was dissolved in mcresol. The solution was stirred for 11 hr and filtered with a Whatman filter paper having pores of size of few microns. The solution of filtered undoped PANi was poured in a Petri dish and dried at 60˚C [
The CSA doped PANi-ZnO nanocomposites were prepared by adding 10 - 50 wt% of camphor sulfonic acid (CSA) into PANi-ZnO nanocomposite powder and grinding it in a smooth agate and mortar for 1 hr for solid state doping. Thin films of the CSA doped PANi-ZnO (50%) nanocomposite were prepared on glass substrate by spin coating technique at 3000 rpm for 40 s and dried on hot plate at 100˚C for 10 min.