Faculty Publications
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Item Investigation of influence of medium ph and sulfate ion concentrations on corrosion behavior of magnesium alloy ZE41(Allerton Press Inc., 2014) Dinodi, N.; Nityananda Shetty, A.Magnesium alloys have emerged as potential structural materials with all capabilities to even replace close contenders; aluminium alloys in weight-critical applications. High susceptibility to corrosion being the only limitation, corrosion of magnesium alloys continues to gather much attention among the material scientists worldwide. ZE41 is one such alloy of magnesium which is increasingly gaining importance as automobile and aerospace material. In the present study the influence of the medium pH and sulfate ion concentrations on the corrosion behavior of magnesium alloy ZE41 has been investigated using electrochemical techniques like the Tafel extrapolation and electrochemical impedance spectroscopy (EIS). The tests have been carried out in a range of conditions, with gradually varying pH and sulfate ion concentration. The morphology and composition of the corroded alloy surface have been determined by the scanning electron microscopy (SEM) and energy dispersion X-ray (EDX) analysis, respectively. The recorded results reflect a trend of a higher corrosion rate associated with a higher sulfate concentration at each pH and with a lower pH at each sulfate concentration. © 2014 Allerton Press, Inc.Item Facile in-situ single step chemical synthesis of reduced graphene oxide-copper oxide-polyaniline nanocomposite and its electrochemical performance for supercapacitor application(Elsevier Ltd, 2017) Viswanathan, V.; Nityananda Shetty, A.Reduced graphene oxide (rGO)-copper oxide-polyaniline nanocomposites were synthesized by facile in-situ single step synthesis method with different weight ratio of polyaniline at fixed weight ratios of copper oxide and reduced graphene oxide (rGO); and characterized by IR spectroscopy, powder XRD, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The electrochemical performances of as synthesized composites were studied using two electrode system in 2 M Na2SO4 as electrolyte by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. The composite with a weight of 300 mg of Polyaniline (PANI), corresponding to the composition (wt %) of rGO6.6%: Cu2O/CuO13.40%: PANI80% (GCP-300) exhibited superior electrochemical characteristics with specific capacitance of 213.20 F g?1, energy density of 18.95 W h kg?1, power density of 545.79 W kg?1, columbic efficiency of 91% and rendered 97.6% of retention of its initial capacitance up to 5000 charge-discharge cycles. The performance is superior to those of binary combinations of constituent materials viz., reduced graphene oxide (rGO), copper oxide and polyaniline, which is attributed to the extent of integration of afore mentioned materials. © 2017 Elsevier LtdItem 2-(4-(Diethylamino)-2-hydroxybenzyledene) Hydrazinecarboamide as Corrosion Inhibitor on AA2024-T3 Aluminium Alloy in 0.5 M Hydrochloric Acid Solution(Pleiades Publishing compmg@maik.ru, 2018) Prakashaiah, B.G.; Nityananda Shetty, A.; Amitharani, B.E.A new compound 2-(4-(diethylamino)-2-hydroxybenzyledene) hydrazinecarboamide (DHBHC) was prepared by the condensation of thiosemicarbazide and diethylaminosalicyaldehyde in ethanol–water mixture and its purity was confirmed with IR, H1 and C13 NMR. Anticorrosion properties of this new compound were studied on the aluminium alloy AA2024-T3 in 0.5M HCl solution at 303 K by potentiodynamic polarization, electrochemical impedance spectroscopy and weight loss method. The inhibition efficiency of DHBHC was found to increase with an increase of its concentration. The inhibition efficiency obtained in this study was 96 ± 3% in the presence of 10 × 10?5 M of DHBHC. The surface morphology of the alloy was investigated both in the presence and in the absence of the inhibitor by field emission scanning electron microscopy, 3D profilometry and X-ray photoelectron spectroscopy. © 2018, Allerton Press, Inc.Item Quick responsive and durable supercapacitive performance of rGO/Zn(OH)2/PANI nanocomposites(Springer, 2021) Viswanathan, A.; Nityananda Shetty, A.; Bharath, S.P.; Mahendra, K.The quick responsive and durable supercapacitive performance was achieved from reduced graphene oxide/zinc hydroxide/polyaniline (rGO5.88%/Zn(OH)211.77%/PANI82.35%) (GZnP82) nanocomposite, synthesized by in-situ single step. The GZnP82 provided a specific capacitance (Cs) of 173.60 F g?1, a specific capacity (Q) of 208.32 C g?1, a specific energy of 34.7220 W h kg?1 and a specific power of 1516.8 W kg?1 at 0.25 A g?1. The GZnP82 exhibits only 28% decay of its initial Cs up to 12500 cycles at 2 A g?1. The GZnP82 is fast in response with the relaxation time (?) of 1.52 s. The capacitance of GZnP82 device obtained from impedance spectroscopy is 1.29 F. The comparison of electrochemical performance of GZnP82 measured from both chronopotentiometry and impedance spectroscopy, with similar reported energy storage materials, apprises that the achieved performances are of similar order; and better than, the reported materials. Most importantly, the addition of Zn(OH)2 has rendered the negative contribution to the GZnP82, as the binary combination of it, the rGO/PANI furnished higher performances than the GZnP82. © 2021, Indian Academy of Sciences.