Bharathiar University

About: Bharathiar University is a education organization based out in Coimbatore, Tamil Nadu, India. It is known for research contribution in the topics: Thin film & Adsorption. The organization has 5812 authors who have published 8628 publications receiving 143934 citations. The organization is also known as: BU.

Structural, vibrational, thermal, and conductivity studies on proton-conducting polymer electrolyte based on poly (N-vinylpyrrolidone)

Abstract: The proton-conducting polymer electrolytes based on poly (N-vinylpyrrolidone) (PVP), doped with ammonium chloride (NH4Cl) in different molar ratios, have been prepared by solution-casting technique using distilled water as solvent. The increase in amorphous nature of the polymer electrolytes has been confirmed by XRD analysis. The FTIR analysis confirms the complex formation of the polymer with the salt. A shift in glass transition temperature (T g) of the PVP/NH4Cl electrolytes has been observed from the DSC thermograms which indicates the interaction between the polymer and the salt. From the AC impedance spectroscopic analysis, the ionic conductivity of 15 mol% NH4Cl-doped PVP polymer complex has been found to be maximum of the order of 2.51 × 10−5 Scm−1 at room temperature. The dependence of T g and conductivity upon salt concentration has been discussed. The linear variation of the proton conductivity of the polymer electrolytes with increasing temperature suggests the Arrhenius type thermally activated process. The activation energy calculated from the Arrhenius plot for all compositions of PVP doped with NH4Cl has been found to vary from 0.49 to 0.92 eV. The dielectric loss curves for the sample 85 mol% PVP:15 mol% NH4Cl reveal the low-frequency β relaxation peak pronounced at high temperature, and it may be caused by side group dipoles. The relaxation parameters of the electrolytes have been obtained by the study of Tanδ as a function of frequency.

Synthesis and characterization of bio-polymer electrolyte based on iota-carrageenan with ammonium thiocyanate and its applications

Abstract: Solid polymer electrolyte based on iota-carrageenan (i-carrageeenan) with ammonium thiocyanate (NH4SCN) has been prepared by solution casting technique using distilled water as solvent. Increase of amorphous nature of the polymer/salt complex has been confirmed by XRD analysis. The complex formation between the polymer and salt has been confirmed by FTIR analysis. A shift in glass transition temperature (Tg) of the i-carrageeenan/ NH4SCN electrolytes has been observed from the DSC thermograms. From AC impedance spectroscopy, the maximum conductivity value has been found to be 3.56 × 10−3 S/cm for i-carrageeenan (1 g): NH4SCN (0.3 wt%) at room temperature. Also it has been observed that the activation energy evaluated from the Arrhenius plots has been found to be low (0.21 eV) for i-carrageeenan (1 g): NH4SCN (0.3 wt%) polymer electrolyte. The ionic transference number has been measured using DC Wagner’s polarization method for highest conducting polymer membrane and the result indicates that the conductivity of the electrolyte is predominantly due to ions. The electrochemical stability of the electrolyte i-carrageeenan (1 g): NH4SCN (0.3 wt%) has been studied by linear sweep voltammetry. Using this maximum ionic conductivity polymer electrolyte, the proton battery and fuel cell have been constructed and the cell parameters have been reported.

Transport mechanism of Cu-ion conducting PVA based solid-polymer electrolyte

Abstract: Copper-ion conducting solid-polymer electrolyte systems based on Polyvinyl alcohol (PVA) has been prepared by solution cast technique. UV-VIS data show a broad peak in the wavelength region 600–800 nm due to complex formation. The 30 wt.% Cu(NO3)2 doped system has a maximum conductivity of 1.6×10−5 Scm−1 at room temperature. The conductance spectrum shows two distinct regions: a dc plateau and a dispersive region. The dielectric spectra show an increase in the dielectric constant with decreasing frequency. The transference number measurements reveal that the transport in these electrolytes is mainly due to ions.

Synchronization of Neural Networks With Control Packet Loss and Time-Varying Delay via Stochastic Sampled-Data Controller

Abstract: This paper addresses the problem of exponential synchronization of neural networks with time-varying delays. A sampled-data controller with stochastically varying sampling intervals is considered. The novelty of this paper lies in the fact that the control packet loss from the controller to the actuator is considered, which may occur in many real-world situations. Sufficient conditions for the exponential synchronization in the mean square sense are derived in terms of linear matrix inequalities (LMIs) by constructing a proper Lyapunov–Krasovskii functional that involves more information about the delay bounds and by employing some inequality techniques. Moreover, the obtained LMIs can be easily checked for their feasibility through any of the available MATLAB tool boxes. Numerical examples are provided to validate the theoretical results.