Nanostructures of polypyrrole (PPy) were synthesized in the presence of different dopants including hydrochloric acid (HCl), ferric chloride (FeCl 3 ), p-toluene sulfonic acid ( p-TSA), camphor sulfonic acid (CSA), and polystyrene sulfonic acid (PSSA), using a simple interfacial oxidative polymerization method. The method is a reliable non-template approach with relatively simple instrumentation, ease of synthesis, and economic viability for synthesizing PPy nanostructures. Morphology of synthesized PPy structures was investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which indicate the formation of one-dimensional (1D) nanofibers with average diameter of 75-180 nm. Energy dispersive spectrum (EDS) of the PPy nanofibers indicates the attachment of the dopants to the PPy backbone; the fact is further confirmed by the Fourier transform infrared (FTIR) spectra of PPy nanostructures. Thermal stabilities of the nanostructures explored using thermal gravimetric analysis (TGA) follow the order PPy-p-TSA > CSA > HCl > FeCl 3 > PSSA. It is noticed that the electrical conductivity (EC) of PPy nanostructures depends upon the nature of dopant (PPy-p-TSA > CSA > HCl > FeCl 3 > PSSA), PPy-p-TSA nanofibers showing the highest EC of 6 T 10 S2 Scm S1 .

No abstract

An improved protocol for generation of viable cormlets from tissue culture derived shoots of saffron has been developed. Multiple shoots were generated from apical buds, small corms and in vitro developed single shoots. Bunches of two to three shoots when cultured on half strength Murashige and Skoog (MS) medium containing 3 mg dm -3 benzyladenine (BA) and 80 g dm -3 sucrose developed 1.89 cormlets per shoot bunch with an average fresh mass of 1.18 g. It took nine months from culture of apical buds to the harvest of cormlets but under field conditions 22 months. Sucrose appeared to be essential for cormlet induction as no cormlets were developed in the medium devoid of sucrose and only 0.29 per shoot in medium containing mannitol. In vitro derived cormlets sprouted from apical and axillary buds on MS medium containing 12 mg dm -3 BA, 3 mg dm -3 indolebutyric acid and 30 g dm -3 sucrose. Daughter cormlet formation from in vitro derived cormlets was also observed.

In the present study, graphene oxide nanoribbons (GONR) and reduced graphene oxide nanoribbons (RGONR) supported polyaniline (PANI) nanocomposites are synthesized via an in situ chemical polymerization method and investigated for supercapacitor electrodes. Electrochemical studies performed by cyclic voltammetry and galvanostatic charge–discharge (GCD) measurements suggest that both nanocomposites possess enhanced specific capacitance (C sp as 740 F/g for GONR/PANI and 1180 F/g for RGONR/PANI at 5 mV/s). GONR/PANI and RGONR/PANI nanocomposites show good rate capability with high C sp upon increasing the current density from 2 to 20 A/g in GCD measurements, approximately 55% decay in C sp value of the nanocomposites is observed compared to pristine PANI (∼70%). The undertaken study signifies enhanced electrical and electrochemical properties of GONR/RGONR supported PANI nanocomposites due to a synergistic effect of GONR/RGONR and PANI. Furthermore, asymmetric devices are fabricated using GONR/RGONR as the negative electrode, while GONR/PANI and RGONR/PANI are used as the positive electrode, which exhibit significant enhancement in energy density and device performance.