A5004111506- Graphene research and applications
- Theoretical and Computational Physics
- Gold and Silver Nanoparticles Synthesis and Applications
- Nanocluster Synthesis and Applications
- 2D Materials and Applications
- MXene and MAX Phase Materials
- Quantum Dots Synthesis And Properties
- Metal and Thin Film Mechanics
- Semiconductor materials and interfaces
- Quantum chaos and dynamical systems
- Semiconductor materials and devices
- Complex Systems and Time Series Analysis
- Advanced Nanomaterials in Catalysis
- Pickering emulsions and particle stabilization
- Thermal properties of materials
- Electrodeposition and Electroless Coatings
- Supercapacitor Materials and Fabrication
- Fluid Dynamics and Thin Films
- nanoparticles nucleation surface interactions
- Force Microscopy Techniques and Applications
- Rheology and Fluid Dynamics Studies
- Chaos control and synchronization
- Anodic Oxide Films and Nanostructures
- Granular flow and fluidized beds
- Plasma Diagnostics and Applications
Gandhigram Rural Institute
2023-2024
Institute of High Performance Computing
2011-2023
Agency for Science, Technology and Research
2011-2023
Star Technology and Research (United States)
2020
National University of Singapore
2019
Brown University
2006
Indian Institute of Science Bangalore
1999-2004
Oxygen Control of Graphene Growth The growth graphene on copper surfaces through the decomposition hydrocarbons such as methane can result in a wide variety crystal domain sizes and morphologies. Hao et al. (p. 720 , published online 24 October; see cover) found that presence surface oxygen could limit number nucleation sites allowed centimeter-scale domains to grow diffusion-limited mechanism. electrical conductivity was comparable exfoliated graphene.
Here, we report a general and facile method for effective layer-by-layer exfoliation of transition metal dichalcogenides (TMDs) graphite in water by using protein, bovine serum albumin (BSA) to produce single-layer nanosheets, which cannot be achieved other commonly used bio- synthetic polymers. Besides serving as an exfoliating agent, BSA can also function strong stabilizing agent against reaggregation nanosheets greatly improving their biocompatibility biomedical applications. With...
How does your garden grow? A facile method can tune the anisotropic growth of TiO2 onto differently shaped gold nanoparticles to form Janus, eccentric, and concentric geometries (see picture). The Janus Au-TiO2 nanostructures were found be energetically stable using calculations, they possess highest catalytic activity out all three due highly accessible, exposed core on one side.
In this work, copper (Cu) species were used as reducing reagents in the colloidal preparation of novel cross-shaped gold (Au) nanostructures oleylamine. The reduction rate can be controlled through an appropriate choice Cu to obtain Au nanocrosses varying sizes. It was found that presence during nucleation stage is crucial formation a branched morphology. Further analysis revealed four primary branches grow along <110> and <001> directions, secondary growth occurs <111> direction....
An effective separation process is developed to remove free protein from the protein-protected gold clusters via co-precipitation with zinc hydroxide on their surface. After dialysis, purified exhibit an enhanced fluorescence for improved sensitive detection and selective visualization.
The collective behavior of dislocations in jerky flow is studied Al-Mg polycrystalline samples subjected to constant strain rate tests. Complementary dynamical, statistical, and multifractal analyses are carried out on the stress-time series recorded during characterize distinct spatiotemporal dynamical regimes. It shown that hopping type $B$ propagating $A$ bands correspond chaotic self-organized critical states, respectively. crossover between these types identified by a large spread...
Controllable synthesis of MoS2 with desired grain morphology via chemical vapor deposition (CVD) or physical (PVD) remains a challenge. Hence, it is important to understand polycrystalline growth and further provide guidelines for its CVD/PVD growth. Here, we formulate kinetic Monte Carlo (kMC) model aiming at predicting the boundary (GB) formation in MoS2. In kMC model, kink nucleation propagation, whose energetic parameters initial nucleus details are either from first-principles...
Wachstumsschub: Ein einfacher Weg wurde gefunden, um das anisotrope Wachstum von TiO2 auf unterschiedlich geformten Goldnanopartikeln in Richtung Janus-, exzentrischer oder konzentrischer Geometrie zu steuern (siehe Bild). Die Au-TiO2-Janus-Nanostrukturen sind nach Berechnungen energetisch stabil, und sie dank des einer Seite gut zugänglichen exponierten Goldkerns die katalytisch aktivsten unter den drei Formen. Detailed facts of importance to specialist readers are published as ”Supporting...
Mass production of large, high-quality single-crystalline graphene is dependent on a complex coupling factors including substrate material, temperature, pressure, gas flow, and the concentration carbon hydrogen species. Recent studies have shown that oxidation surface such as Cu before introduction C precursor, methane, results in significant increase growth rate while number nuclei decreases. We report phase-field model, where we include effects oxygen nuclei, energetics at front, island...
We describe a surfactant-driven method to synthesize highly monodisperse CdSe-seeded CdS tetrapods with differing arm lengths and diameters in order examine their effects on self-assembly. exploited the phenomena of weak- strong-binding capping groups tune length diameter uniform shape achieved >95% yield. Afterward, we utilize these particles overcome some key problems assembly anisotropic shaped particles. Intriguingly, found that certain pack like fishbone chains, which was greatly...
Abstract Over the last two decades, remarkable progress has been made in use of computational methods for understanding 2D materials growth. The aim this Review is to provide an overview several state‐of‐the‐art modelling and simulation First, current status materials, their major growth are addressed. Next, applications ab initio method discussed, focusing on reaction precursors, diffusion adatoms, energetics kinetics fronts, effects substrates. Then, molecular dynamics approach with...
Abstract The ultrafast growth of large-area, high-quality WSe 2 domains with a compact triangular morphology has recently been achieved on gold substrate via chemical vapor deposition. However, the underlying mechanism responsible for remains elusive. Here, we first analyze processes and identify two possible pathways that might achieve growth: Path 1, fast edge attachment diffusion; 2, kink nucleation propagation. We perform kinetic Monte Carlo simulations first-principles calculations to...
Dendritic structures, such as snowflakes, have been observed in nature far-from-equilibrium growth conditions. Mimicking these structures at the nanometer scale can result nanomaterials with interesting properties for applications, plasmonics and biosensors. However, reliable production systematic fine-tuning morphologies of nanostructures, novel hierarchical or complex along theoretical understanding processes, are still major challenges field. Here, we report a new method using pH to...
A diffraction-limited three-dimensional (3D) direct laser writing (DLW) system based on two-photon polymerization can routinely pattern structures at the 100 nm length scale. Several schemes have been developed to improve patterning resolution of 3D DLW but often require customized resist formulations or multi-wavelength exposures. Here, we introduce a scheme produce suspended nano-webs with feature sizes below 10 in IP-Dip using sub-threshold exposure conditions commercial system. The...
The analysis of experimental time series, obtained from single and polycrystals subjected to constant strain rate tests, reports an intriguing dynamical crossover a low-dimensional chaotic state at medium rates infinite-dimensional power-law stress drops high rates. We present the results extensive study all aspects Portevin--Le Chatelier (PLC) effect within context recent model that reproduces this crossover. characterize dynamics by studying distribution Lyapunov exponents as function...
We perform systematic two-dimensional energetic analysis to study the stability of various nanostructures formed by dewetting solid films deposited on patterned substrates. Our analytical results show that controlling system parameters such as substrate surface pattern, film thickness and wetting angle, a variety equilibrium can be obtained. Phase diagrams are presented complex relations between these nanostructure morphologies. further carry out both phase field simulations experiments...
Low-energy ion bombardment produces spontaneous periodic structures (sputter ripples) on many surfaces. Continuum theories describe the pattern formation in terms of ion-surface interactions and surface relaxation kinetics, but features these models (such as defect concentration) are unknown or difficult to determine. In this work, we present results kinetic Monte Carlo simulations that model evolution using discrete atomistic versions physical processes included continuum theories. From...
Abstract We introduce an approach to fabricate ordered arrays of 10-nm-scale silica-filled apertures in a metal film without etching or liftoff. Using low temperature (<400°C) thermal dewetting films guided by nano-patterned templates, with aspect ratios up 5:1 are demonstrated. Apertures form spontaneously during the process need for further processing. Although phenomenon has been well studied, this is first demonstration its use fabrication nanoapertures spatially controllable manner....
Various graphene morphologies (compact hexagonal, dendritic, and circular domains) have been observed during chemical vapor deposition (CVD) growth on Cu substrate. The existing all-atom kinetic Monte Carlo (kMC) models, however, are unable to reproduce all these morphologies, suggesting that some crucial atomistic events dictate the morphology missing. In this work, we propose an kMC model simulate CVD Besides usual events, such as diffusion of carbon species substrate, their attachments...
A precisely controlled destabilization of gold thiolate clusters is demonstrated to grow 12 {110}-faceted dodecahedra with greatly enhanced catalytic capability, and reveal the growth mechanism by DFT simulations. This advances our understanding nanocrystal opens a new window for controlling dissociation produce nanocrystals specific shapes. As service authors readers, this journal provides supporting information supplied authors. Such materials are peer reviewed may be re-organized online...