A5033798081- Electrochemical Analysis and Applications
- Conducting polymers and applications
- Force Microscopy Techniques and Applications
- Analytical Chemistry and Sensors
- Theoretical and Computational Physics
- Molecular Junctions and Nanostructures
- Electrocatalysts for Energy Conversion
- Electrodeposition and Electroless Coatings
- Rheology and Fluid Dynamics Studies
- Transition Metal Oxide Nanomaterials
- Organic Electronics and Photovoltaics
- Complex Systems and Time Series Analysis
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Sensor Technologies
- Electrostatics and Colloid Interactions
- Supercapacitor Materials and Fabrication
- Advanced Sensor and Energy Harvesting Materials
- Ionic liquids properties and applications
- Surface and Thin Film Phenomena
- Material Dynamics and Properties
- Copper-based nanomaterials and applications
- Quantum Dots Synthesis And Properties
- Polymer crystallization and properties
- Blood properties and coagulation
- Advanced battery technologies research
University of Delhi
2015-2024
Pacific Dental College and Hospital
2024
Chaudhary Charan Singh University
2024
Forest Research Institute
2020
Indian Institute of Technology Hyderabad
2010
Pennsylvania State University
2003
University of Freiburg
2000-2001
Rutherford Appleton Laboratory
1999
University of Leeds
1999
University of Sheffield
1999
We present experiments and theory on the melt dynamics of monodisperse entangled polymers H-shaped architecture. Frequency-dependent rheological data a series polyisoprene H-polymers are in good agreement with tube model that combines path-length fluctuation (like star polymer melts) at high frequency, reptation self-entangled "cross-bars" low frequencies linear melts). account explicitly for mild polydispersity. Nonlinear step-strain transient shear extension confirm presence relaxation...
Composite thin films of poly(3,4-ethylenedioxythiophene) (PEDOT)-enwrapped functionalized multiwalled carbon nanotubes (MWCNTs) have been synthesized over multiple length scales by electropolymerization the monomer without use any other supporting electrolyte. The MWCNTs are incorporated into positively charged polymer deposit as counterions during oxidative electropolymerization. morphology, electrochemistry, and electrochromism PEDOT-MWCNT compared with those control PEDOT doped triflate...
We present the theoretical results elucidating influence of uncompensated solution resistance on anomalous Warburg’s impedance. Here, we obtain mathematical expression which incorporates diffusion at rough electrode/electrolyte interface and bulk via phenomenological length scales—diffusion ((D/ω)1/2) pseudoreaction penetration (LΩ). The roughness is contained in through surface structure factor, can be used to describe statistically any random morphology. Detailed analysis for realistic...
We generalize linearized Gouy-Chapman-Stern theory of electric double layer for nanostructured and morphologically disordered electrodes. Equation capacitance is obtained using linear Gouy-Chapman (GC) or Debye-$\rm{\ddot{u}}$ckel equation potential near complex electrode/electrolyte interface. The effect surface morphology an electrode on (EDL) "multiple scattering formalism" in curvature. result expressed terms the ratio Gouy screening length local principal radii curvature surface. also...
A generalized model for dynamics of the electric double layer (EDL) at a heterogeneous and rough electrode is developed using Debye–Falkenhagen equation potential. The influence surface heterogeneities which causes distribution in relaxation time compact included through current balance boundary constraint outer Helmholtz layer. results admittance response are obtained deterministic stochastic roughness. expressed as functional an arbitrary profile roughness power spectrum understood terms...
We develop a phenomenological theory of electric double layer (EDL) dynamics at complex bimodal electrode morphology, viz. arbitrary shaped mesostructures with embedded heterogeneous micropores. The the diffuse mesoscale is described through Debye-Falkenhagen (DF) model EDL relaxation and micropores by employing de Levie's transmission line (TL) model. influence mesostructure on incorporated elegantly, Green's function (obtained multiple scattering formalism) expressing local admittance in...
We study the influence of topology on extension branched polymers subjected to external forces. Such forces can be applied mechanically (by micromanipulation techniques such as laser tweezers) or electrically (in case charged polymers). focus unfold dynamics star and dendrimer type structures. Some dynamical quantities interest are: (i) structural average mean monomer displacement, (ii) elastic loss moduli (iii) displacement a specified monomer. In Gaussian-type approach, depend only...
We study the stretch dynamics of flexible dendritic polymers (dendrimers and stars) under external forces. work in framework bead-spring model with hydrodynamic interactions (HI) take spacers different length into account. The applied fields may, e.g., be mechanical or electrical origin. motion a specific monomer, time evolution (the mean distance monomer on which force acts from center mass polymer) also elastic moduli. analyze how these dynamic properties depend underlying topology, i.e.,...
Poly(3-hexylthiophene) (P3HT) matrix has been chemically doped (redox doping) by ferric chloride (FeCl3) with different molar concentrations to get P3HT–FeCl3 charge-transfer complexes. The effect of redox doping on photo-physical, structural, and morphological properties dc electrical conductivity P3HT matrices examined. measured films pristine complexes in the temperature range 6–300 K. Analysis data reveals that 40–300 K, is predominantly governed Mott's 3-dimensional variable hopping...
Abstract Composite films of poly(3,4‐ethylenedioxythiophene) (PEDOT)‐coated over functionalized multiwalled coiled and linear carbon nanotubes (CNTs) have been fabricated by a simple oxidative electropolymerization route. The nanotubular morphology the polymer–CNT composite is responsible for lower charge transfer impedance, internal resistance, superior capacitive response in comparison to that shown control PEDOT film doped trifluoromethanesulfonate ions. This facile electrochemistry...
We developed a theory for the anomalous admittance and constant phase angle behavior of an irregular interface operating under diffusion controlled charge-transfer condition. Interfacial irregularity is modeled as realistic random fractal, which characterized statistically isotropic self-affine fractals on limited length scales. The power spectrum such surface fractal approximated in terms law function intermediate wave numbers. This has four morphological parameters. They are dimension...
We develop a theory for an electrochemical way of detecting the roughness metal surface. Here we relate surface structure factor to average reaction current measured on and obtain its inverse too. Under small large time regime analysis extract information regarding various morphological features
We developed a theory for the generalized Gerischer admittance an irregular interface, operating under diffusion and homogeneous kinetics coupled with fast heterogeneous charge transfer reaction. The expressions are obtained deterministic surface (viz, exact mathematical function of roughness profile is known) as well stochastic statistical properties profiles known). A power spectrum or structure factor sufficient to characterize geometrical irregularities. An elegant expression functional...