scispace - formally typeset
Search or ask a question
Author

Shri Singh

Other affiliations: University of Guelph
Bio: Shri Singh is an academic researcher from Banaras Hindu University. The author has contributed to research in topics: Liquid crystal & Phase transition. The author has an hindex of 18, co-authored 97 publications receiving 1446 citations. Previous affiliations of Shri Singh include University of Guelph.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, the authors developed a function that is sensitive to many-body screening of the anisotropy in dense molecular fluids and applied it to dipolar fluids and to ST2 water.
Abstract: We developed a function that is sensitive to many‐body screening of the anisotropy in dense molecular fluids and applied it to dipolar fluids and to ST2 water. For these fluids, the function was found to be oscillatory with distance and to become damped, for dipolar fluids, with increasing strength of the dipole moment. We then compared this function to the screening implied by the Gray–Gubbins and RAM reference state potentials. For ST2 water these comparisons suggested that a composite potential made up of equal proportions of the RAM and the Gray–Gubbins potential might be better than either the RAM or the Gray–Gubbins potentials alone.

1 citations

Journal ArticleDOI
TL;DR: In this article, the effect of dye dispersion on the surface domain formation at the interface of alignment layer and ferroelectric liquid crystal molecules has been studied, showing that the suppression of these surface domains are beneficial from the application point of view, as these domains are responsible for the scattering of light and suppressing of these domains will increase the contrast and brightness of the display.
Abstract: The effect of dye dispersion on the surface domain formation at the interface of alignment layer and ferroelectric liquid crystal molecules has been studied. The observed dielectric data clearly shows the existence of two relaxation modes in ferroelectric liquid crystal. The relaxation, which shows its contribution in KHz region, takes place due to the formation of domains at surface interface. In both the cases i.e. dye dispersion in Felix17/100 and in DOBAMBC, relaxation strength decreases with dispersion of dye, indicating the suppression of domains. Relaxation frequency in case of Felix 17/100 decreases while it increases for DOBAMBC with the dispersion of dye. The suppression of these surface domains are beneficial from the application point of view, as these domains are responsible for the scattering of light and suppression of these domains will increase the contrast and brightness of the display.

Cited by
More filters
Journal ArticleDOI
TL;DR: This critical review covers various aspects of recent research on discotic liquid crystals, in particular, molecular design concepts, supramolecular structure, processing into ordered thin films and fabrication of electronic devices.
Abstract: Discotic (disc-like) molecules typically comprising a rigid aromatic core and flexible peripheral chains have been attracting growing interest because of their fundamental importance as model systems for the study of charge and energy transport and due to the possibilities of their application in organic electronic devices. This critical review covers various aspects of recent research on discotic liquid crystals, in particular, molecular design concepts, supramolecular structure, processing into ordered thin films and fabrication of electronic devices. The chemical structure of the conjugated core of discotic molecules governs, to a large extent, their intramolecular electronic properties. Variation of the peripheral flexible chains and of the aromatic core is decisive for the tuning of self-assembly in solution and in bulk. Supramolecular organization of discotic molecules can be effectively controlled by the choice of the processing methods. In particular, approaches to obtain suitable macroscopic orientations of columnar superstructures on surfaces, that is, planar uniaxial or homeotropic alignment, are discussed together with appropriate processing techniques. Finally, an overview of charge transport in discotic materials and their application in optoelectronic devices is given (234 references).

1,278 citations

Journal ArticleDOI
TL;DR: This Review focuses on the developments of light-driven liquid crystalline materials containing photochromic components over the past decade, and the developed materials possess huge potential for applications in optics, photonics, adaptive materials, nanotechnology, etc.
Abstract: Light-driven phenomena both in living systems and nonliving materials have enabled truly fascinating and incredible dynamic architectures with terrific forms and functions. Recently, liquid crystalline materials endowed with photoresponsive capability have emerged as enticing systems. In this Review, we focus on the developments of light-driven liquid crystalline materials containing photochromic components over the past decade. Design and synthesis of photochromic liquid crystals (LCs), photoinduced phase transitions in LC, and photoalignment and photoorientation of LCs have been covered. Photomodulation of pitch, polarization, lattice constant and handedness inversion of chiral LCs is discussed. Light-driven phenomena and properties of liquid crystalline polymers, elastomers, and networks have also been analyzed. The applications of photoinduced phase transitions, photoalignment, photomodulation of chiral LCs, and photomobile polymers have been highlighted wherever appropriate. The combination of photoc...

576 citations

Book ChapterDOI
TL;DR: The main objective of field-cycling experiments [231, 367] is to obtain information on the spectral density of the fluctuating spin interactions in a frequency range as wide as possible as mentioned in this paper.

547 citations

Journal ArticleDOI
TL;DR: Recent results help elucidate structure and hydrogen-bonded interactions, as well as showcase a successful interplay between theory and experiment in gas-phase spectroscopy.
Abstract: Gas-phase spectroscopy lends itself ideally to the study of isolated molecules and provides important data for comparison with theory. In recent years, we have seen enormous progress in the study of biomolecular building blocks in the gas phase. The motivation for such work is threefold: (a) It is important to distinguish between intrinsic molecular properties and properties that result from the biological environment. (b) Gas-phase spectroscopy of clusters provides insights into fundamental interactions and into microsolvation. (c) Gas-phase data support quantum-chemical calculations. This review focuses on the current status of (poly)amino acids and DNA bases. Recent results help elucidate structure and hydrogen-bonded interactions, as well as showcase a successful interplay between theory and experiment.

359 citations

Journal ArticleDOI
TL;DR: Different strategies commonly used to formulate the free-energy functional of complex fluids for either phenomena-oriented applications or as a generic description of the thermodynamic nonideality owing to various components of intermolecular forces are discussed.
Abstract: Density-functional theory (DFT) and its variations provide a fruitful approach to the computational modeling of the microscopic structures and phase behavior of soft-condensed matter. The methodology takes deep root in quantum mechanics but shares a mathematical similarity with a number of classical approaches in statistical mechanics. This review discusses different strategies commonly used to formulate the free-energy functional of complex fluids for either phenomena-oriented applications or as a generic description of the thermodynamic nonideality owing to various components of intermolecular forces. We emphasize the connections among different schemes of DFT approximations, their underlying assumptions, and inherent limitations. We also address extensions of equilibrium DFT to phenomenological theories for the dynamic properties of complex fluids and for the kinetics of phase transitions. In addition, we highlight the recent literature concerning applications of DFT to diverse static and time-dependent phenomena in complex fluids.

343 citations