Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
4 results
Search Results
Item Electrochemical characterization of a polar ?-phase poly (vinylidene fluoride) gel electrolyte in sodium ion cell(Elsevier B.V., 2019) Janakiraman, S.; Surendran, A.; Biswal, R.; Ghosh, S.; Anandhan, S.; Adyam, A.A polar ?-phase poly (vinylidene fluoride) (PVDF) membrane is developed through the electrospinning method. PVDF gel electrolyte for sodium ion batteries was obtained by saturating the bare porous membrane in a liquid electrolyte, 1 M NaClO4 in EC: DEC (1:1 vol%). The physical and electrochemical characteristics of the polar ?-phase PVDF membrane are explored by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Atomic force microscope (AFM), sodium ion conductivity, linear sweep voltammetry (LSV) and sodium ion transference number. The ionic conductivity of a polar ?-phase PVDF gel electrolyte exhibited 9.2 × 10?4 S cm?1, higher than the commercially used Celgard® 2400 membrane 0.36 × 10?4 S cm?1 at ambient temperature. The electrochemical expolarations of the sodium ion half-cell (Na2/3Fe1/2Mn1/2O2) as a cathode and sodium metal as a counter electrode) conducted from PVDF gel electrolyte are analysed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). CV of the battery showed a pseudo capacitive nature. The equivalent circuit model of the sodium ion cell brought out the effect of dipole moments in the polymer chains on the battery performance. © 2018 Elsevier B.V.Item New cyanopyridine based conjugated polymers carrying auxiliary electron donors: From molecular design to blue emissive PLEDs(Elsevier Ltd, 2020) Pilicode, N.; Naik, P.; K M, K.M.; Acharya, M.; Satyanarayan, M.N.; Vasudeva Adhikari, A.V.Three new D-A (Donor-Acceptor) configured conjugated polymers, i.e. PPy1-3, centered on strong electron accepting cyanopyridine scaffold carrying varied auxiliary donors, viz. phenylene (PPy1), biphenyl (PPy2), and fluorene (PPy3) were designed and synthesized as blue emitters for PLEDs. The new polymers were subjected to spectral, thermal, photophysical and electrochemical characterization. Also, computational studies (DFT) were performed on the repeating units of polymer using Turbomole 7.2 V software package at the B3LYP/TZVP hybrid levels. Further, their weight average molecular masses were found to be 38.8 kDa, 38.9 kDa and 57.7 kDa, respectively as determined by GPC technique. Furthermore, the new polymers PPy1-3, were shown to be stable thermally up to 308–374 °C. Evidently, they exhibited good photophysical behavior with their optical energy band gaps of 2.53–2.64 eV. Finally, the polymers PPy1-3 were employed as an active emissive layer in standard ITO/PEDOT:PSS/Polymer/Al configured PLEDs. Interestingly, at 12 V all the newly fabricated devices exhibit a stable blue characteristic electroluminescence with low threshold voltages of 3.40–5.20 V, confirming an efficient injection of electrons in the diodes. From the results, it is clear that, the polymers PPy1-3, can be considered as prospective blue light emitters for PLED application. © 2019 Elsevier LtdItem New cyanopyridine-based ?-conjugative poly(azomethine)s: Synthesis, characterization and electroluminescence studies(John Wiley and Sons Ltd, 2021) Pilicode, N.; Naik, P.; K M, K.M.; Acharya, M.; Satyanarayan, M.N.; Vasudeva Adhikari, A.V.Four new Schiff-base type conjugative polymers (CPs), that is, Py1-4 carrying a strong electron-withdrawing cyanopyridine scaffold coupled with different electron-donating aromatic/heteroaromatic moieties were synthesized from their respective co-monomers by simple poly-condensation route. They were subjected to structural, thermal, photophysical, and electrochemical characterizations and theoretical investigations in order to identify their suitability in polymer light-emitting diode (PLED) application. All these polymers showed good film-forming ability and exhibited favorable photophysical behaviors with an optical bandgap in the order of 2.54-2.68 eV. Further, their electrochemical data were used to evaluate highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels. Finally, Py1-4 were successfully employed as blue-light emitter in the construction of new ITO/PEDOT:PSS/ Py1-4/Al configured light-emitting diodes (LED), and the fabricated devices demonstrated stable blue electroluminescence behavior endorsing an effective electrons injection in the PLEDs. © 2020 John Wiley & Sons LtdItem Electrochemical deposition and characterisation of NiTi alloy coatings for better corrosion protection(Taylor and Francis Ltd., 2024) G, H.S.; Hegde, A.C.The present study reports the electrochemical deposition and characterisation of Nickel-Titanium (NiTi) alloy coatings on mild steel (MS) from citrate bath having nickel sulphate and titanium oxysulphate as salts, tri-sodium citrate as complexing agent and glycerol as the brightener. Bath composition and operating variables were optimised by the conventional Hull cell method for bright and uniform coating. NiTi alloy coatings were developed at varied current densities (1.0 A/dm2 to 4.0 A/dm2), keeping pH = 4.0. The corrosion behaviours of NiTi alloy coatings were evaluated by electrochemical AC and DC methods in a 3.5 per cent sodium chloride solution. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) techniques were used to study the phase structure, surface morphology and chemical composition of the coatings, respectively. The observed facts stand to the reason that the bath follows induced type co-deposition in the range of current density studied. Corrosion studies validated that NiTi alloy coating deposited at 4.0 A/dm2 is the most corrosion-resistant among all other current densities. This highest corrosion stability of NiTi alloy, corresponding to 4.0 A/dm2 is attributed to high wt.% of Ti (i.e. 3.5%). The decrease in corrosion rate towards high current density was analysed and discussed. © 2023 Canadian Institute of Mining, Metallurgy and Petroleum.