Santanu Chaudhuri

University of Illinois Chicago | UIC · Department of Civil and Material Engineering

In order to deploy machine learning in a real-world self-driving laboratory where data acquisition is costly and there are multiple competing design criteria, systems need to be able to intelligently sample while balancing performance trade-offs and constraints. For these reasons, we present an active learning process based on multiobjective black-...

ASME Sec(III) Div(5) code-certified structural alloys for Molten (halide) Salt Reactors (MSRs) such as 800H, SS316, and IN617 have significant Cr content. This makes them readily-degradable in molten halide salts due to the thermodynamic favorability of soluble chromium halide formation. It is therefore imperative to discover alloys with corrosion...

Insufficient availability of molten salt corrosion‐resistant alloys severely limits the fruition of a variety of promising molten salt technologies that could otherwise have significant societal impacts. To accelerate alloy development for molten salt applications and develop fundamental understanding of corrosion in these environments, here an int...

Advancements in scientific instrument sensors and connected devices provide unprecedented insight into ongoing experiments and present new opportunities for control, optimization, and steering. However, the diversity of sensors and heterogeneity of their data result in make it challenging to fully realize these new opportunities. Organizing and syn...

Granular molecular crystals show a large variation in the orientation, length, shape, and cohesive interactions of interfaces when embedded in a polymer matrix. But the determination of the associated excess of free energy is not straightforward, especially due to the entropic contribution which is not negligible for molecular compounds. The surfac...

Despite significant efforts in multiscale modeling of multiphase materials, the effective mechanical response of the components still remains elusive due to the complexity of heterogeneous microstructures. This work presents a multiscale modeling approach for determining the effective elastic properties and mechanical behavior of heterogeneous mate...

The design of corrosion-resistant high entropy alloys (CR-HEAs) is challenging due to the alloys' virtually astrological composition space. To facilitate this, efficient and reliable high-throughput exploratory approaches are needed. Toward this end, the current work reports a first-principles-based approach exploiting the correlations between work...

Insufficient availability of molten salt corrosion-resistant alloys severely limits the fruition of a variety of promising molten salt technologies that could otherwise have significant societal impacts. To accelerate alloy development for molten salt applications and develop fundamental understanding of corrosion in these environments, here we pre...

The supercell approach to first-principles calculations of an alloy's full phonon spectrum is computationally expensive. It is therefore rarely used for calculating temperature dependent free energies of alloy phases or for calculating alloy phase diagrams. Amid the wider acceptance of uncertainty evaluation and the use of more efficient methods fo...

Atmospheric pressure plasma (APP) is an emerging technology for surface modification and depositing plasma coating without a vacuum chamber in ambient atmosphere to improve corrosion protection and paint adhesion for aerospace and energy applications. Current APP-based platforms lack the ability to control the surface chemistry of the coating for d...

We have developed a continuum modeling approach, grounded in classical physical chemistry, based on the following assumptions that the thermodynamic states in the material can be represented by local stationary averages of the pressure (stress), temperature, and mass fractions computed from atomistic simulation, and that the mixture has well-define...

The design of next-generation alloys through the integrated computational materials engineering (ICME) approach relies on multiscale computer simulations to provide thermodynamic properties when experiments are difficult to conduct. Atomistic methods such as density functional theory (DFT) and molecular dynamics (MD) have been successful in predict...

Flame Spray Pyrolysis (FSP) is a manufacturing technique to mass produce engineered nanoparticles for applications in catalysis, energy materials, composites, and more. FSP instruments are highly dependent on a number of adjustable parameters, including fuel injection rate, fuel-oxygen mixtures, and temperature, which can greatly affect the quality...

The design of next-generation alloys through the Integrated Computational Materials Engineering (ICME) approach relies on multi-scale computer simulations to provide thermodynamic properties when experiments are difficult to conduct. Atomistic methods such as Density Functional Theory (DFT) and Molecular Dynamics (MD) have been successful in predic...

Processing parameters during laser based additive manufacturing affect the fluid flow, heat transfer and solidification characteristics in the melt pool, leading to microstructural variants of texture, grain size, and morphology. A finite volume based Computational Fluid Dynamics (CFD) model coupled with solidification physics has been developed to...

An atmospheric pressure plasma (APP) system offers advanced, cost-effective processing routes for surface cleaning without a vacuum chamber. The appeal of APP systems in surface cleaning, however, is reduced by lack of a predictive link among the processing parameters, surface-plasma reactions, and plasma chemistry responsible for efficient removal...

IoT devices and sensor networks present new opportunities for measuring, monitoring, and guiding scientific experiments. Sensors, cameras, and instruments can be combined to provide previously unachievable insights into the state of ongoing experiments. However, IoT devices can vary greatly in the type, volume, and velocity of data they generate, m...

We have developed a continuum modeling approach, grounded in classical physical chemistry, based on the following assumptions: (1) that the states in the material can be represented by local stationary averages of the pressure (stress), temperature, and mass fractions computed from atomistic simulation, (2) and that the mixture has well-defined mol...

The design of corrosion-resistant alloys requires a thorough understanding of the chemistry, microstructure, and its evolution in atmospheric conditions. While the alloy processing conditions and chemistry determine the microstructure according to the phase diagram, the microstructure determines the behavior when exposed to corrosive environments....

The quantum-chemistry based force field (FF) developed for HMX by Smith and Bharadwaj (SB) [G. D. Smith and R. K. Bharadwaj, J. Phys. Chem. B, 1999, 103(18), 3570–3575] is transferred to another nitramine of different stoichiometry: hexanitrohexaazaisowurtzitane (CL-20 or HNIW). The modification of a single parameter alongside a very small number o...

Corrosion-resistance Microstructure Design using Mesoscale Modeling Environment for Additive Manufacturing for Co-Cr Alloys - Volume 25 Supplement - Xiaoli Yan, Arash Samei, Brian Mercer, Pikee Priya, Santanu Chaudhuri

Solidification and microstructures of fast quenched cobalt (from 1950K to 600K) are studied using molecular dynamics simulations. Two types of microstructures, a nanocrystalline type consisting of multiple grains and a lamellar type are obtained. The lamellar type microstructure shows a dominant layering direction with fcc phases separated by stack...

Engineering magnesium alloys for Army applications requires an understanding of corrosion behavior, including how grain boundaries (GBs) or second phases/ intermetallics affect corrosion at the atomic scale. In magnesium–aluminum alloys, precipitation of the Mg17Al12 phase at GBs can have important implications for mechanical and corrosion behavior...

Binders play a pivotal role in solid propellants and polymer-bonded energetic composites in providing the means for safe transport, storage, and use. The fundamental role of binders is known qualitatively, but the exact role in modification of chemistry and thermal transport is hard to quantify. Thermochemical response of a commonly used binder, hy...

The ECAP experiment (Evaporative Coatings at Atmosphere Pressure) was developed at CPMI (Center for Plasma Materials Interaction at UIUC) as a device and a method for multicomponent metal coatings deposition at atmosphere pressure utilizing a 2.45 GHz microwave plasma torch. The device is capable of coating deposition from a solid metal state and f...

Currently, there is no universal atomistic approach for simulating the combustion chemistry of a moving deflagration wave in condensed phase energetic materials. A reactive molecular dynamics based approach is used to identify the thermochemical events behind the formation and the propagation of a thermally initiated deflagration wave in the conden...

Rapid materials discovery in inorganic chemistry should combine predictive computational tools with fast experimental syntheses. We apply such a tandem approach to explore the Ba-Ru-S phase space, where no ternary compounds are yet known to exist. Related ternary oxide ruthenates and ternary iron sulfides exhibit interesting electronic properties d...

In Mg-Al alloys, experiments show that Volta potential changes with Al concentration in eutectic α-phase and the potential is nobler around the cathodic precipitate β-phase (Mg17Al12). Other elemental impurities in the anodic matrix can also change corrosion potential. Density functional theory computations are used to investigate the effects of su...

Increasingly frequent petroleum contamination in water bodies continues to threaten our ecosystem, which lacks efficient and safe remediation tactics both on macro and nanoscales. Current nanomaterial and dispersant remediation methods neglect to investigate their adverse environmental and biological impact, which can lead to a synergistic chemical...

Predictive simulations connecting chemistry that follow the shock or thermal initiation of energetic materials to subsequent deflagration or detonation events is currently outside the realm of possibilities. Molecular dynamics and first-principles based dynamics have made progress in understanding reactions in picosecond to nanosecond time scale. R...

We describe the ignition of an explosive crystal of gamma-phase RDX due to a thermal hot spot with reactive molecular dynamics (RMD), with first-principles trained, reactive force field based molecular potentials that represents an extremely complex reaction network. The RMD simulation is analyzed by sorting molecular product fragments into high an...

A computational multiphysics model for simulating the formation and breakup of droplets from axisymmetric charged liquid jets in electric fields is developed. A fully-coupled approach is used to combine two-phase flow, electrostatics, and transport of charged species via diffusion, convection, and migration. A conservative level-set method is shown...

Materials that can serve as long-lived barriers to biofluids are essential to the development of any type of chronic electronic implant. Devices such as cardiac pacemakers and cochlear implants use bulk metal or ceramic packages as hermetic enclosures for the electronics. Emerging classes of flexible, biointegrated electronic systems demand similar...

Ability to accelerate the morphological evolution of nanoscale precipitates is a fundamental challenge for atomistic simulations. Kinetic Monte Carlo (KMC) methodology is an effective approach for accelerating the evolution of nanoscale systems that are dominated by so-called rare events. The quality and accuracy of energy landscape used in KMC cal...

We present a mirrored atomistic and continuum framework that is used to describe the ignition of energetic materials, and a high-pressure phase of RDX in particular. The continuum formulation uses meaningful averages of thermodynamic properties obtained from the atomistic simulation and a simplification of enormously complex reaction kinetics. In p...

The phonon mediated vibrational up-pumping mechanisms assume an intact lattice and climbing of a vibrational ladder using strongly correlated multi-phonon dynamics under equilibrium or near-equilibrium conditions. Important dynamic processes far from-equilibrium in regions of large temperature gradient after the onset of decomposition reactions in...

Development of new Mg-alloys needs greater efforts in systematic evaluation of corrosion protection methods under service environments. A deeper understanding of microscale and nanoscale metallurgy is needed to slow down corrosion. Results from our multiscale modeling effort will be presented to demonstrate the power of first-principle theories in...

Vertically oriented structures of single crystalline conductors and semiconductors are of great technological importance due to their directional charge carrier transport, high device density, and interesting optical properties. However, creating such architectures for organic electronic materials remains challenging. Here, we report a facile, cont...

Chemical events that lead to thermal initiation and spontaneous ignition of high-pressure phase of RDX are presented using reactive molecular dynamics simulations. In order to initiate the chemistry behind thermal ignition, approximately 5% of RDX crystal is subjected to a constant temperature thermal pulse of various time durations to create hot s...

Electrocatalytic reduction of oxygen is composed of multiple steps, including the diffusion-adsorption-dissociation of molecular oxygen. This study explores the role of electrical double layer in aqueous medium in quantifying the rate of these coupled electrochemical processes at the electrode interface during oxygen reduction. The electronic, ener...

Pressure effects on the Raman vibrations of an energetic crystal FOX-7 (1, 1-diamino-2, 2-dinitroethene) were examined using density functional theory (DFT) calculations. High accuracy calculations were performed with a periodic plane-wave DFT method using norm-conserving pseudopotentials. Different exchange-correlation functionals were examined fo...

Shock response of energetic materials is controlled by a combination of mechanical response, thermal, transport, and chemical properties. How these properties interplay in condensed-phase energetic materials is of fundamental interest for improving predictive capabilities. Due to unknown nature of chemistry during the evolution and growth of high-t...

In this work, we explored the energetic and configurational properties of molecular oxygen adsorption on Cu(111) in water using classical mechanics and electronic structure based computations. It has been found that the structure of the water network surrounding the oxygen at the electrolyte/metal interface can be determinant in the adsorption conf...

Coupling molecular scale reaction kinetics with macroscopic combustion behavior is critical to understanding the influences of intermediate chemistry on energy propagation, yet bridging this multi-scale gap is challenging. This study integrates ab initio quantum chemical calculations and condensed phase density functional theory to elucidate factor...

A series of coatings were developed that help prevent corrosion of aluminum alloy 2024 (AA2024). The coatings were based on an aliphatic polyurethane–polyoligomeric silsesquioxane (PU–POSS) resin. The materials were selected to exhibit a high level of hydrophobicity, which is expected to increase the moisture barrier properties, and thereby improve...

Development of new Mg-alloys needs greater efforts in systematic evaluation of corrosion protection methods under service environments. A deeper understanding of microscale and nanoscale metallurgy is needed to slow down corrosion. Results from our multiscale modeling effort will be presented to demonstrate the power of first-principle theories in...

A multiscale simulation-based approach is presented for predicting anti-icing properties of nanocomposite coatings. Development of robust anti-icing coatings is a challenging task. An anti-icing coating that can prevent in-flight icing is of particular interest to the aircraft industry. A multiscale simulations based approach is developed to provid...

Development of new Mg-alloys needs greater efforts in systematic evaluation of corrosion protection methods under service environments. A deeper understanding of microscale and nanoscale metallurgy is needed to slow down corrosion. Results from our multiscale modeling effort will be presented to demonstrate the power of first-principle theories in...

Activation of molecular hydrogen is the first step in producing many important industrial chemicals that have so far required expensive noble-metal catalysts and thermal activation. We demonstrate here that aluminium doped with very small amounts of titanium can activate molecular hydrogen at temperatures as low as 90 K. Using an approach that uses...

Activation of molecular hydrogen is the first step in producing many important industrial chemicals that have so far required expensive noble-metal catalysts and thermal activation. We demonstrate here that aluminium doped with very small amounts of titanium can activate molecular hydrogen at temperatures as low as 90 K. Using an approach that uses...

Reactivity of MgO surfaces towards dissociative adsorption of water is crucial in determining the protective performance of oxide films formed on top of Mg alloy surfaces. Engineers and scientists have repeatedly reported that heavy metal contamination could significantly affect the oxide film stability towards water. We performed first-principles...

In-flight icing occurs when supercooled water droplets suspended in the atmosphere impinge on cold aircraft surfaces. Thin layers of accreted ice significantly increase aerodynamic drag while thick layers of ice severely alter the aerodynamics of control surfaces and lift. Chunks of ice can break away from the airframe and cowlings and be ingested...

Corrosion prevention in light-weight alloys is currently an area of major research for civilian, aerospace, and defense applications. In order to understand thoroughly the complex corrosion system and hence develop effective and “green” corrosion prevention strategies, predictive modeling is believed to be an essential tool. This work presents a ne...

Alanates are promising hydrogen storage materials, but have poor re-hydrogenation kinetics. Decomposition ootnotetextJ. Alloys Compd. 1997, 253, 1. of NaAlH4 can be made reversible at reasonable temperatures and pressures by adding titanium. There is however little understanding of the role of Ti as a catalyst, ootnotetextJ Am Chem Soc 2006, 128, (...

A combined approach, using solid state NMR and Molecular Dynamics (MD) simulations, has been employed in this work to investigate fluoride-ion motion in the PbSnF4 family of anionic conductors, materials that contain double layers of Sn2+ and M2+ cations. 19F MAS NMR spectra of PbSnF4 and BaSnF4 show that the fluoride ions are mobile on the NMR tim...

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We studied self-propagated combustion synthesis of transition-metal-doped tetragonal ZrO2 (t-ZrO2) with first principles-based one-dimensional diffusion reaction model. The optimal reaction condition for the combustion process was investigated by calculating energetic stability and surface reactivity of oxygen vacancy defects on (101) surface termi...

A multiscale quantum/classical-framework for hydrophobicity and UV absorption in heterogeneous coatings is presented. Atomistic water droplet simulations on coated oxide surface are used to define nanoscale contact-angles using a new numerical technique called the dynamic local contact angle (DLCA) method. The DLCA method is well suited to calculat...

The effect of particle size on combustion efficiency is an important factor in combustion research. Gas-phase aluminum clusters in oxidizing environment constitute a relatively simple and extensively studied system. In an attempt to underscore the correlation between electronic structure, finite size effect, and reactivity in small aluminum cluster...

Vacancy-assisted reaction on tetragonal (t-) ZrO2 surface is important for its potential in combustion synthesis, barrier coating and as solid electrolyte in solid-oxide fuel cells. Doping or alloying the surface could significantly enhance the surface reactivity and transport by altering the electronic structure of the surface. We performed first-...

We have used reactive force field (ReaxFF) to investigate the mechanism of interaction of alanes on Al(111) surface. Our simulations show that, on the Al(111) surface, alanes oligomerize into larger alanes. In addition, from our simulations, adsorption of atomic hydrogen on Al(111) surface leads to the formation of alanes via H-induced etching of a...

Corrosion prevention in light-weight alloys is currently an area of major research for civilian, aerospace, and defense applications. The models for corrosion rates and electrochemical processes currently used primarily rely upon empirical parameterization using experimental data. We present a first-principles linked multiscale model that can integ...

Combustion reactions of Aluminum particles in Teflon oxidizer environment was investigated using first-principles derived RRKM unimolecular rate constant calculations and reactive molecular dynamics simulations. In our study, quantum chemical theories are used as a first step to formulate the kinetic model for different reaction channels between Te...

The local bonding and atomic environments in the Ni-catalyzed destabilized system LiBH4/MgH2 and the quaternary borohydride-amide phase Li3BN2H8, were studied by x-ray absorption spectroscopy. In both cases the Ni catalyst was introduced as NiCl2 and a qualitative comparison of the Ni K-edge near-edge structure suggests the Ni2+ is reduced to prima...

Gas-phase reactions between aluminum particles and Teflon fragments were studied to develop a fundamental understanding of the decomposition reactions and combustion processes of the Al-Teflon composites. The reactions were investigated theoretically using ab initio calculations at the MP2/aug-cc-pVDZ level, with the final thermokinetic data obtain...

Alanes are believed to be the mass transport intermediate in many hydrogen storage reactions and thus important for understanding rehydrogenation kinetics for alanates and AlH3. Combining density functional theory (DFT) and surface infrared (IR) spectroscopy, we provide atomistic details about the formation of alanes on the Al(111) surface, a model...

Alane clusters (AlxHy) are believed to be the ubiquitous intermediates in hydrogen storage reactions for a wide variety of alanates (LiAlH4, NaAlH4) currently considered for hydrogen storage. The formation and behavior of alanes at surfaces appear to control and limit the efficiency of hydrogen storage. In particular, hydrogen adsorption on the Al(...

Aluminum hydride, AlH3, is the most well-known alane. Though thermodynamically unstable under ambient conditions, it is easily prepared in a metastable state that will undergo controlled thermal decomposition to produce H2 and Al at around 100 °C. AlH3 contains 10.1 wt % hydrogen and has a density of 1.48 g/mL and is therefore of interest for on-bo...

The reported activity of nanoscale NaH and titanocene towards catalytic reduction of terminal alkenes using molecular hydrogen is surprising considering that both NaH bulk and titanocene are inactive by themselves. In this work, the role of Ti dopants, the importance of NaH nanoclusters and role of the solvent (THF) and cocatalyst (titanocene) are...

We have performed Ti K-edge EXAFS and XANES measurements on 4 and 3 wt% TiCl3-activated NaAlH4 and (LiBH4+0.5MgH2) and Ni K-edge measurements on 3 and 11 wt% NiCl2-activated (LiBH4+0.5MgH2) and (Li3BN2H8) - prospective hydrogen storage materials. The valence of Ti and Ni is close to zero and invariant during hydrogen cycling. None of the metals ent...

Pressure-induced structural, electronic, and thermodynamic changes in alpha-AlH3 were investigated using synchrotron x-ray powder diffraction and density-functional theory. No first-order structural transitions were observed up to 7GPa . However, increasing Bragg peak asymmetry with pressure suggests a possible monoclinic distortion at moderate pre...

Cubic nanoparticles of alpha-AlF(3) containing 864 and 2048 atoms were investigated by using molecular dynamics simulations. Significant structural rearrangements of these particles occurred, primarily at the edges and corners of the particles, and 3 and 5 membered (Al-F-)(n) ring structures were observed in addition to the 4-membered rings seen in...

We report the results of an experimental and theoretical study of hydrogen storage in sodium alanate (NaAlH(4)). Reversible hydrogen storage in this material is dependent on the presence of 2-4% Ti dopant. Our combined study shows that the role of Ti may be linked entirely to Ti-containing active catalytic sites in the metallic Al phase present in...

The octahedron tilt transitions of ABX_3 perovskite-structure materials lead to an anti-polar (or antiferroelectric) arrangement of dipoles, with the low temperature structure having six sublattices polarized along various crystallographic directions. It is shown that an important mechanism driving the transition is long range dipole-dipole forces...

A comprehensive research effort on the atomistic mechanisms underlying hydrogen storage in Ti-doped NaAlH4 is aimed at deriving a knowledge base for the rational optimization of this and other related complex hydride materials. Our investigation focuses on the role of the Ti dopants in promoting reversible hydrogenation, a key requirement for any p...