A5029878674- Liquid Crystal Research Advancements
- Molecular spectroscopy and chirality
- Photonic Crystals and Applications
- Surfactants and Colloidal Systems
- Nonlinear Dynamics and Pattern Formation
- Material Dynamics and Properties
- Plant Reproductive Biology
- Advanced Materials and Mechanics
- Micro and Nano Robotics
- Pickering emulsions and particle stabilization
- Hedgehog Signaling Pathway Studies
- Pancreatic and Hepatic Oncology Research
- Photonic and Optical Devices
- Plant and animal studies
- Epigenetics and DNA Methylation
- Synthesis and Properties of Aromatic Compounds
- Cell death mechanisms and regulation
- Spectroscopy and Quantum Chemical Studies
- Theoretical and Computational Physics
- Cytokine Signaling Pathways and Interactions
- Acute Myeloid Leukemia Research
- Orbital Angular Momentum in Optics
- Cancer-related molecular mechanisms research
- Microfluidic and Bio-sensing Technologies
- Estrogen and related hormone effects
University of Hyderabad
2016-2025
NYU Langone Health
2023
Tokyo Institute of Technology
2008-2011
Raman Research Institute
2001-2004
Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy that harbors mutations in homologous recombination-repair (HR-repair) proteins 20%-25% of cases. Defects HR impart specific vulnerability to poly ADP ribose polymerase inhibitors and platinum-containing chemotherapy tumor cells. However, not all patients who receive these therapies respond, many initially respond ultimately develop resistance. Inactivation the pathway associated with overexpression theta (Polθ, or POLQ)....
We measured the splay $({K}_{11})$ and bend $({K}_{33})$ elastic constants in nematic phase of a bent-core liquid crystal. In vicinity nematic-isotropic transition temperature ${K}_{33}$ is proportional to square order parameter. range ${K}_{11}$ increases monotonically with decreasing temperature, whereas practically independent smaller than ${K}_{11}$. exhibits pretransitional slow divergence toward smectic becomes slightly larger The small explained on basis strong coupling bent shape...
We report temperature dependent measurements of birefringence (Δn), splay (K11), bend (K33) elastic constants and rotational viscosity (γ1) mixtures rod-like bent-core molecules. K11 Δn remain almost constant for all the whereas K33 is always lower than further decreases with increasing concentration molecules in mixtures. Apart from large jump at nematic-isotropic transition (NI) a significant nematic-smectic (NS) also observed that increases mol% compound Rotational by factor four when...
It is demonstrated that interactions between nanoparticles and topological defects induce a twist-grain boundary phase in chiral liquid crystal. The occurrence of this phase, the analogue Shubnikov type-II superconductors, driven by direct surface-functionalized CdSe quantum dots screw dislocations. shown that, within an adaptive-defect-core-targeting mechanism, appropriate size functionalization adapt to qualitatively different cores such as disclination lines This mechanism enables...
In emulsions of multicomponent fluids, the dispersed phase forms tiny droplets in continuous phase. situ control and manipulation to achieve diversity emulsion for emerging applications is challenging. a liquid crystal-based emulsion, surface anchoring molecules at isotropic fluid-liquid crystal interface introduces elastic distortions that result anisotropic interparticle interactions, similar electrostatic interactions between multipoles, which also lends naming analogy as dipoles,...
We report the measurement of birefringence, dielectric constant, splay, bend elastic constants and rotational viscosity in nematic phase (N) a hockey stick-shaped compound exhibiting smectic-A (SmA) anticlinic smectic-C (SmCa) transitions at lower temperature. It is found that physical properties are significantly different than calamitics partially similar to bent-core liquid crystals. exhibits positive negative anisotropy. The optical thermal measurements show all first order....
We report the synthesis of new laterally alkyl substituted high birefringent quaterphenyl and phenylethynyltolane liquid crystals with isothiocyanate terminal group. The thermal optical properties such as birefringence are measured discussed based on their molecular structures. compounds exhibit (Δn) in range 0.44–0.63, expected to be appropriate components nematic mixtures for various applications.
We report on experimental studies of the viscoelastic, magnetodielectric, and magnetoviscosity properties ferromagnetic liquid crystals (LCs) prepared by dispersing nanoparticles in a thermotropic LC. Both splay elastic constant rotational viscosity ferronematic LCs are found to be considerably lower than that pure LC advantageous device applications. The show unique magnetodielectric response at very low magnetic fields useful for smart fluid
We report magnetic field tuning of the structure and Whispering Gallery Mode lasing from ferromagnetic nematic liquid crystal micro-droplets. Microlasers were prepared by dispersing a crystal, containing nanoparticles fluorescent dye, in glycerol-lecithin matrix. The droplets exhibit radial director structure, which shows elastic distortion at very low external field. dye doped show lasing, is tunable WGM modes linear with wavelength-shift order 1 nm/100 mT. Depending on geometry, WGMs are...
The recent discovery of nematic liquid crystals with polar order (ferroelectric) has created immense interest. Despite intensive research, several physical properties this crystal are yet to be investigated and understood. Here, we report experimental studies on the surface alignment, birefringence, flexoelectric coefficient a $({N}_{\mathrm{F}})$ crystal. Our experiments directly reveal that splay fluctuations influence birefringence degrees above nonpolar $(N)$ phase transition...
We report a strong discontinuous orientational transition (anchoring transition) of liquid-crystal molecules with large transverse dipole moment. A perfluoropolymer was used as an alignment layer and the observed from planar to homeotropic decreasing temperature in nematic phase. Conversely gradual variation tilt angle conical liquid crystal comparatively smaller moment on same layer. The experimental results clearly demonstrate competition between short-range dipolar force long-range van...
A new approach for the design of a room temperature <italic>N</italic><sub>D</sub> liquid crystal dimer plausibly through folding dimeric unit as suggested by modelling in mesophase derived from X-ray scattering results and DFT calculations.
We report experimental studies on the phase transitions and physical properties of colloidal suspensions BaTiO3 nanoparticles two cyanobiphenyl liquid crystals (4-pentyl-4ʹ-cyanobiphenyl 4-octyl-4ʹ-cyanobiphenyl). From differential scanning calorimetric measurements, we show that have antagonistic effect isotropic to nematic smectic-A transitions. The birefringence, dielectric anisotropy splay elastic constant remain almost unchanged, whereas bend rotational viscosity decrease considerably....
We report measurements of the temperature variations physical parameters in ambient-temperature nematic liquid crystal mixtures bent-core (BC) and rodlike molecules (5CB): birefringence $\ensuremath{\Delta}n$; static dielectric constants ${\ensuremath{\epsilon}}_{||}$ ${\ensuremath{\epsilon}}_{\ensuremath{\perp}}$; splay ${K}_{11}$ bend ${K}_{33}$ elastic constants; rotational viscosity ${\ensuremath{\gamma}}_{1}$; diffusion coefficients ${D}_{||}$ ${D}_{\ensuremath{\perp}}$ a microsphere....
This paper uncovers a self-propelling mechanism by which metal-dielectric Janus colloids in liquid-crystalline film move converting the energy of an oscillating electric field. The authors are able to control their trajectories varying field amplitude and frequency, further showing that propulsive flows arise around particles, resembling those generated swimming microorganisms, through force dipoles with centers displaced towards metallic hemisphere.
We report an unusual electroconvection in the nematic phase of a bent-core liquid crystal. In voltage-frequency diagram, two frequency regions exhibiting prewavy stripe patterns were found, as reported by Wiant found that these stripes never show extinction dark when cells rotated under crossed polarizers. Based on color interchange between neighboring rotation or analyzer, twisted molecular orientation is suggested; i.e., directors are alternately from top to bottom surfaces with pretilt...
We measured the splay (K11) and bend (K33) elastic constants in nematic phase of a liquid crystal with T-shaped molecules. find that ratio, K33/K11 ≃1 entire range except very close to Sm-A (SN) transition. Both K33 K11 show pretransitional divergence as SN transition is approached from higher temperature. The suggests length (L) effective width (D) ratio (i.e., L/D ) significantly smaller due presence long flexible lateral group, compared rigid rodlike It argued apart extra contribution...
The authors have demonstrated a novel bistable memory device writable by laser beam. utilizes the hysteresis of temperature-driven discontinuous anchoring transition (orientation change) in dye-doped nematic liquid crystal. light irradiation switches stable orientation from homeotropic to planar crystal on perfluoropolymer surface. thickness recorded lines comes down as low ∼20 μm. images were kept at least for day, i.e., effect. We also showed that temperature range was lowered room using...
A unique phase transition between a uniaxial orthogonal with random polar order SmAPR and antiferroelectric SmAPA is found in series of symmetric achiral bent-core liquid crystals. The weakly first or continuous. X-ray diffraction, electro-optical, optical second harmonic generation dielectric methods, confirmed that the occurs from locally ordered to macroscopically antiferroelectrically phase.
We report studies on the whispering gallery mode (WGM) resonance of liquid crystal (LC) droplets across smectic-A (SmA) to nematic phase transition. The quality factor (Q) in SmA decreases rapidly with a characteristic slope change at SmA-N In phase, Q-factor is linearly proportional birefringence (Δn). discuss effect topological defect transformation WGM resonance. study expected be very useful for detecting subtle transitions among LC mesophases.
Abstract We report measurements of birefringence, bend elastic constant, principal dielectric constants and conductivities as functions temperature in the nematic phase 4′-butyl-4-heptyl-bicyclohexyl-4-carbonitrile (CCN-47). The compound exhibits a small birefringence large negative anisotropy. Surprisingly, it shows conductivity anisotropy, which probably owes its origin to structural details molecules. orientational order parameters (S) are estimated from both they agree well entire range....
Three series of asymmetric bent-core compounds were synthesized and their mesomorphic properties studied. All the possess 2-methylresorcinol as a central unit stilbene bridge main element in structure. Molecules I II only saturated terminal chains while those III have one or both unsaturated chain/s. The mesophases characterized by using optical polarizing microscopy, differential scanning calorimetry, X-ray diffraction, electrooptic dielectric measurements, miscibility studies. exhibit...
We have studied mesogenic properties in the smectic-${A}_{d}{P}_{A}$ phase of an asymmetric bent-core liquid crystal by means polarizing optical microscopy, second-harmonic generation (SHG), electro-optical (EO), and dielectric measurements. In homeotropically aligned cells, EO switching is clearly observed from a schlieren texture with both four- two-brush defects to uniform bright domain under application very low in-plane electric field below $1\text{ }\text{V}/\ensuremath{\mu}\text{m}$....