Nucleation Parameters Research Articles

Irradiation Effects on Tensile Properties of Reduced Activation Ferritic/Martensitic Steel: A Micromechanical-Damage-Model-Based Numerical Investigation

The tensile properties of reduced activation ferritic/martensitic (RAFM) steels are significantly influenced by neutron irradiation. Here, a mechanism-based model taking account of the typical ductile damage process of void nucleation, growth, and coalescence was used to study the temperature and irradiation effects. The elastic–plastic response of RAFM steels irradiated up to 20 dpa was investigated by applying the GTN model coupled with different work hardening models. Through a numerical study of tensile curves, the GTN parameters were identified reasonably and satisfying simulation results were obtained. A combination of Swift law and Voce law was used to define the flow behavior of irradiated RAFM steels. The deformation localization could be adjusted effectively via setting the nucleation parameter εn close to the strain where necking occurs. Because εn changed with uniform elongation, εn decreased with the testing temperature and rose with an irradiation temperature above 300 °C. The nucleation parameter fn increased with the testing temperature for RAFM steels before irradiation. For irradiated RAFM steels, fn barely changed when the irradiation temperature was below 300 °C and then it rose at a higher irradiation temperature. Meanwhile, the ultimate strength of the simulated and experimental curves showed good agreement, indicating that this method can be applied to engineering design.

Simulation and Study of Influencing Factors on the Solidification Microstructure of Hazelett Continuous Casting Slabs Using CAFE Model.

The Hazelett continuous casting and rolling process represents a leading-edge production method for cold-rolled aluminum sheet and strip billets in the world. Its solidification microstructure significantly influences the quality of billets produced for cold rolling of aluminum sheets and strips. In this study, employing the CAFE (Cellular Automaton-Finite Element) method, we developed a coupled computational model to simulate the solidification microstructure in the Hazelett continuous casting process. We investigated the impact of nucleation parameters, casting temperature, and continuous casting speed on the microstructural evolution of the continuous casting billet. Through integrated metallographic analyses, we aimed to elucidate the controlling mechanisms underlying the Hazelett continuous casting process and its resultant microstructure. The results demonstrate that the equiaxed rate of grains increases with an increase in nucleation density, and the grain size decreases under constant cooling strength. With other nucleation parameters held constant, the grain size decreases as undercooling increases, and the columnar crystal zone expands. The nucleation density of the Hazelett continuous casting aluminum alloy has been determined to range between 1011 m-3 and 1013 m-3, and the undercooling ranges between 1 °C and 2.5 °C. The solidified grain structure can be controlled between 35 μm and 72 μm. The grain size of the continuous casting billet increases with an increase in pouring temperature and decreases as the casting speed increases. Elevating the pouring temperature positively impacts the fraction of high-angle grain boundaries and promotes the dendritic to equiaxed grain transition. Moreover, there exists potential for further optimization of continuous casting process parameters.

Simulation of Solidification Structure in the Vacuum Arc Remelting Process of Titanium Alloy TC4 Based on 3D CAFE Method

Vacuum arc remelting is the main production method of titanium alloy ingots at present. In order to obtain good quality ingots, it is of great significance to study the formation of the solidification structure of ingots via vacuum arc remelting. In order to select and optimize the nucleation parameters for the solidification microstructure simulation of an ingot, a 3D CAFE model for microstructure evolution during vacuum arc remelting was established, taking into account heat transfer, flow, and solute diffusion. The Gaussian distribution continuous nucleation model and extended KGT model were used to describe the grain nucleation and dendrite tip growth rates, respectively. The multi-point mass source and moving boundary method were used to simulate the ingot growth. The results show that there are three typical crystal regions in the solidification structure of vacuum arc remelting titanium alloy ingots, namely the surface fine crystal region, columnar crystal region, and central equiaxed crystal region. The proportion of the columnar crystal region in the solidification structure of an ingot increases gradually with the increase in the undercooling of the maximum bulk nucleation. With an increase in the maximum bulk nucleation density, the equiaxed grain zone gradually increases, and the grain size gradually decreases. The proportion of the columnar crystal region in the solidification structure of an ingot increases gradually with an increase in the undercooling of the maximum bulk nucleation. The maximum volume nucleation variance has no obvious effect on the change in the solidification structure. When the maximum volume nucleation undercooling is 5.5 K, the maximum volume nucleation standard deviation is 4 K, and the maximum volume nucleation density is 5 × 108. The solidification structure simulation results are in good agreement with the experimental results.

Crystal nucleation in an AlNiZr metallic liquid: Within and beyond classical nucleation theory

The Classical Nucleation Theory (CNT) has played a key role in crystal nucleation studies since the 19th century and has significantly advanced the understanding of nucleation. However, certain key assumptions of CNT, such as a compact and spherical nucleating cluster and the concept of individual diffusive jumps are questionable. The results of molecular dynamics (MD) studies of crystal nucleation in a Al20Ni60Zr20 metallic liquid demonstrate that the nucleating cluster is neither spherical nor compact. The seeding method was employed to determine the critical cluster size and nucleation parameters from CNT, which were then compared to those derived from the Mean First Passage Time (MFPT) method. While the CNT-based nucleation rate aligns well with experimental data from similar metallic liquids, the MFPT rate differs significantly. Further, contrary to the assumption of individual jumps for atoms to join the nucleating cluster, a cooperative mechanism of attachment or detachment is observed. This is accompanied by synchronized changes in the local potential energy. Similar cooperative motion also appeared in a non-classical nucleation process, particularly during the coalescence of nuclei.

Advanced microstructural path modeling of primary recrystallization in aluminum alloys AA5182 and AA5657

AbstractWhen analyzing recrystallization kinetics data, it is extremely important to use a model, which has appropriate assumptions for nucleation and growth, including spatial distribution of nuclei, nucleation rate, growth rate, and directionality. In the present work, we reveal how advanced microstructural path modeling (MPM) can successfully fit kinetics data for the complex recrystallization of two different industrial aluminum alloys. Simpler models have failed to fit the data over the entire recrystallization period. The new model allows for spatially clustered nucleation and for different growth rates in different sample directions, whereby the grains evolve with an aspect ratio different from 1. Based on the MPM analysis, the specific nucleation and growth parameters as well as the recrystallized grain sizes are deduced, and the recrystallization characteristics of the two alloys are compared. The work demonstrates the power of quantitative metallography and the wealth of recrystallization information that may be obtained from MPM modeling of such stereological data.

Insight into the nucleation behavior of tiamulin hydrogen fumarate methanol solvate in methanol-ethyl acetate binary mixtures

To investigate the nucleation behavior of tiamulin hydrogen fumarate methanol solvate (THFMS), the solubility, induction time, and metastable zone width (MSZW) of THFMS in methanol-ethyl acetate binary mixtures were measured. The nucleation potential model, which is based on the classical nucleation theory and correlates the induction time and MSZW, has been employed to deal with the experimental data and estimate the interfacial energy and the critical nucleation potential. The estimated values determined from the nucleation potential model are in accordance with the experimental values. The interfacial energy and the critical nucleation potential of THFMS steadily decrease with the increasing saturation temperature, whereas those of THFMS initially decrease and subsequently increase as the ethyl acetate content increases. The results demonstrate that an increase in saturation temperature leads to enhanced nucleation favorability, while the difficulty of nucleation initially decreases and then increases with increasing ethyl acetate content. Furthermore, the critical nucleation parameters, including the critical Gibbs free energy, the critical nucleus size, and the critical number of molecules in a nucleus, exhibit the same trend in alterations regarding both saturation temperature and ethyl acetate content.

Unraveling the concomitant polymorphism phenomenon in crystallization process: A case study on risperidone in ethyl acetate

Concomitant polymorphism is a widespread occurrence in industrial crystallization processes. A thorough understanding of this phenomenon is essential to prevent the emergence of undesirable polymorphs and ensure the production of high-quality products. In this study, the induction time method was employed to investigate the concomitant polymorphism phenomenon of risperidone in ethyl acetate. The impact of crystallization temperature and stirring rate on the concomitant polymorphism region was explored. Additionally, an analysis of the nucleation tendencies of risperidone form I and form II was conducted from both thermodynamic and kinetic perspectives. Based on the induction time theory, the nucleation parameters of form I and form II were calculated. Through an examination of the change in these nucleation parameters with supersaturation, a comprehensive explanation was provided for the reasons behind the occurrence of concomitant polymorphism and the nucleation behavior of form I and form II under varying degrees of supersaturation. Moreover, the concomitant polymorphism phenomenon during the slow-cooling crystallization process was investigated, and the relationship between operational conditions and the concomitant polymorphism region was discussed.

Controlling Physical and Biochemical Parameters of Actin Nucleation Using a Patterned Model Lipid Membrane.

Self-assembly of nanoscale actin cytoskeletal proteins into filamentous networks requires organizing actin nucleation areas on the plasma membrane through recruiting actin nucleators and nucleation-promoting factors (NPFs) to the areas. To investigate impacts of the nucleation geometry on actin network assembly, we localized NPF or nucleator on defined micropatterns of laterally mobile lipid bilayers confined in a framework of a polymerized lipid bilayer. We demonstrated that actin network assembly in purified protein mixtures was confined on NPF- or nucleator-localized fluid bilayers. By controlling the shape and size of nucleation areas as well as the density and types of localized NPFs and nucleators, we showed that these parameters regulate actin network architectures. Actin network assembly in Xenopus egg extracts was also spatially controlled by patterning bilayers containing phosphatidylinositol 4,5-bisphoshate (PI(4,5)P2), an essential lipid signaling mediator. Therefore, the system provides a promising platform to investigate the physical and biochemical principles for actin network assembly.

Nucleation kinetics, chemical etching, hirshfeld surface, and photoluminescence of Rubidium hydrogen oxalate dihydrate NLO single crystal

The nucleation dynamics of a semi-organic Rubidium hydrogen oxalate dihydrate (RbHOH) crystal were assessed using double-distilled water as a solvent medium to obtain good quality crystal using the solution growth technique. Gravimetric analysis of solubility revealed that it has a positive temperature coefficient of solubility, which is appropriate for bulk growth. Other nucleation parameters such as metastable zonewidth, induction period, and interfacial energy were carried out using the classical theory of nucleation. The photoconductivity experiments reveal that the grown crystal exhibits a positive photoconductivity nature. Chemical etching and atomic force microscopy (AFM) experiments were performed on the produced crystal surface. From AFM experiments, effectively assessed amplitude parameters were calculated. Etching studies showed the presence of etch pit patterns such as tiny hillocks and rectangular shapes. Intermolecular interactions were analysed by using Hirshfeld surface analysis. In the photoluminescence (PL) studies, the grown crystal indicates green emission peaks at 519 nm, and the bandgap energy is found to be 4.8 eV. At room temperature, the refractive index of the RbHOH crystal was determined to be 1.669. The nonlinear optical (NLO) efficiency of the grown crystal was examined using a second harmonic generation efficiency test, and it was determined to be 0.58 times that of KDP.

Size-Independent Nucleation and Growth Model of Potassium Sulfate from Supersaturated Solution Produced by Stirred Crystallization.

This paper explores the kinetics of the crystallization of potassium sulfate in a stirred bed crystallizer through experimental investigation. Employing classical nucleation theory, the homogeneous and heterogeneous nucleation mechanisms of potassium sulfate were investigated. The induction time and critical nucleation parameters, including the surface tension (γ), critical nucleation radius (r*), critical nucleation free energy (ΔG*), and critical nucleation molecule number (i*), were meticulously determined under varying temperatures and supersaturation ratios. The experimental findings revealed that as the temperature and supersaturation ratio increased, the induction time, critical nucleation free energy, critical nucleation radius, and critical molecule number decreased whereas the nucleation rate increased. The crystalline shape remains relatively unaltered with respect to temperature and supersaturation ratio, yet the particle size (D10, D50, D90) increases as the supersaturation and temperature increase. The variations in the measured nucleation parameters align well with the predictions of classical nucleation theory. Furthermore, the kinetic equations of crystal nucleation and the growth rate in a stirred crystallization system were fitted using population balance equations. The results demonstrate that the growth rate increases with increasing supersaturation and stirring rates. Additionally, the effects of the parameters in the nucleation rate equation suggested that the suspension density exerted the greatest influence, followed by the supersaturation ratio and stirring rate. This extensive research provides invaluable theoretical guidance for optimizing the crystallization process and designing industrial crystallizers.

Simulation and Experimental Study of Fluid Flow and Solidification Behavior in Thin Slabs Continuous Casting Process under Secondary Electromagnetic Stirring

During the thin slab continuous casting process of silicon steel, electromagnetic stirring (EMS) can control the flow, heat transfer, and solidification of molten steel through electromagnetic force. Herein, a 3D mathematical model coupling the fluid flow, heat transfer, solidification, and the electromagnetic field is built. The effects of varied current intensities on the flow, heat transfer, and solidification of molten steel in the thin slab under secondary EMS are explored based on applying the electromagnetic brake in the mold region. In the findings, it is demonstrated that increasing the current intensity increases the flow rate and vorticity of the molten steel in the second cooling zone, eliminating the superheating phenomenon and improving the uniformity of the molten steel's temperature distribution. Meanwhile, based on the nucleation and growth parameters determined from thermal simulation experiments, the cellular automation finite‐element model is used to simulate the microstructure evolution during the solidification of thin slab. In the results, it is shown that the stirring energy increases when the current intensity increases, potentially promoting equiaxed crystal growth and grain refinement. Compared to the production sample, a reasonable qualitative agreement is achieved for the grain morphology, equiaxed crystal ratio, and columnar to equiaxed transition.

Investigation of nucleation parameters and third order nonlinear optical properties of triglycine sodiummolybdate single crystals

In this paper, nucleation parameters such as induction period, interfacial tension, metastable zone width, radius of critical nucleus and Gibbs free energy change in solution- grown triglycine sodium molybdate (TGSM) single crystals are studied. The solubility of TGSM at different temperatures has been determined. The induction period and metastable zone width have been experimentally found for optimizing the growth process. Various critical nucleation parameters have been calculated from the experimentally obtained values based on the classical nucleation theory. The nucleation rate is found to increase with the growth of the supersaturation value. The third order non-linear parameters such as absorption coefficient (β), susceptibility (χ (3) ) and refractive index (n 2 ) obtained from the Z-scan analysis confirm the self focusing and reverse saturation absorption nature of the grown crystals.

A new constitutive model for salt rock under cyclic loadings based on state variables

Underground salt rock caverns are ideal for national strategic energy storage, compressed air energy storage, and CO2 storage. Operation periods of salt cavern storage can be affected by periodic injection of gases during production/charging and discharging activities, thus causing fatigue damage to surrounding rock. It is therefore necessary to establish a model that can accurately characterize the evolution process of fatigue damage in salt rock under cyclic loading. This is a necessary input into the design of salt cavern storage systems and for the evaluation of their operation and safety. Relying on the rheological properties and cracks of salt rock and their effects on the bearing capacity of materials, this paper establishes a fatigue damage constitutive model of salt rock, using the rheological characteristics of rock and the deformation–crack expansion relationship. First, the time-varying state variable is introduced through the classical Norton model to characterize the degree of hardening; this is in order to modify the relationship between the stress deformation rate and the correlation of the historical path of loading and unloading of salt rock. Then, based on the relationship between crack damage and effective stress development under deformation conditions, a fatigue damage constitutive model of salt rock is established. Finally, using cyclic loading and unloading data of salt rock under different stress ratios or confining pressures, we verify and compare the model parameters. The results show that: (1) The model can accurately predict the fatigue deformation characteristics of salt rock under different cyclic loading and unloading paths and can better characterize the interaction between deformation and stress path; (2) In this model, parameter a affects stage II while parameter b affects stage I of salt rock fatigue deformation. This can be understood as the factor representing the relationship between stress and deformation rate of salt rock; (3) Parameter d0 characterizing the initial nucleation area and parameter μd representing crack growth rate factor jointly affect/modify the stress–strain relationship in the critical failure stage or stage III of the model.

Experimental investigations on parameter identification and failure predictions of titanium alloy by Gurson–Tvergaard–Needleman model

This study focused on the experimental investigations on parameter identification and failure prediction of Ti-6Al-4 V by Gurson–Tvergaard–Needleman (GTN) model. Two approaches, i.e., direct (by image processing of SEM observations) and indirect measurements (by the reduction of effective Young’s modulus or FE trail-and-error), were used to determine the GTN parameters. Through digital image processed SEM micrographs of uniaxial tensile specimens at different deformation stages, the developments of void volume fraction (VVF) were obtained and compared with that from indirect measurements. The three nucleation parameters can then be analytically derived from this experimentally obtained VVF developments. The critical VVF at void coalescence was directly measured through a SEM observation of the section surface around the fracture region of uniaxial tensile specimen, and this value is also consistent with that from indirect measurement. However, as the matrix of a fracture surface is characterized with an obvious varying grayscale due to its dimple morphology, the VVF at final fracture is suggested to be determined from FE trial-and-error rather than a direct measurement of the fracture surface to avoid error induced by subjective judgements. Consistency of the determined GTN parameters was verified through failure predictions on notched tension (R = 6, 20, 100), notched Arcan tests (R = 1, 3, 5), and cracked Arcan tests (SECS, DECS, and CCS), which proved that GTN model with parameters from this experimental investigation cannot only predict the macroscopic mechanical behavior of ductile metals, but also well match the entire damage evolution, from void nucleation to final fracture.

Validation and application of cellular automaton model for microstructure evolution in IN718 during directed energy deposition

In Directed Energy Deposition (DED), the complex and nonuniform thermal history during the laser heating and cooling cycles determines the as-built microstructures and defects and thus affects the ultimate mechanical properties of fabricated parts. In this study, a highly parallel solidification microstructure model based on the Cellular-Automaton method is developed to predict the grain structure evolution in solid-solution strengthened Ni superalloys, IN718. Through coupling with the DED process model via Simufact, the grain structures in single tracks and a multiple-track multiple-layer block are predicted and compared with experiments. Parametric studies are performed to investigate the impact of key parameters in the stochastic nucleation model and calibrate the nucleation parameters, including nucleation density, nucleation undercooling, and its standard derivation. The predictions capture the general grain growth behavior, including remelting, epitaxial growth, and columnar-to-equiaxed transition, with a quantitative agreement with experimental results in terms of grain size and misorientation. This study demonstrates that the 3D grain structural model coupled with a process model has established the capability to model grain evolution for additive manufacturing processes, illustrating a powerful tool to assist the materials design and process development in additive manufacturing.

An extreme value statistics model of heterogeneous ice nucleation for quantifying the stability of supercooled aqueous systems.

The propensity of water to remain in a metastable liquid state at temperatures below its equilibrium melting point holds significant potential for cryopreserving biological material such as tissues and organs. The benefits conferred are a direct result of progressively reducing metabolic expenditure due to colder temperatures while simultaneously avoiding the irreversible damage caused by the crystallization of ice. Unfortunately, the freezing of water in bulk systems of clinical relevance is dominated by random heterogeneous nucleation initiated by uncharacterized trace impurities, and the marked unpredictability of this behavior has prevented the implementation of supercooling outside of controlled laboratory settings and in volumes larger than a few milliliters. Here, we develop a statistical model that jointly captures both the inherent stochastic nature of nucleation using conventional Poisson statistics as well as the random variability of heterogeneous nucleation catalysis through bivariate extreme value statistics. Individually, these two classes of models cannot account for both the time-dependent nature of nucleation and the sample-to-sample variability associated with heterogeneous catalysis, and traditional extreme value models have only considered variations of the characteristic nucleation temperature. We conduct a series of constant cooling rate and isothermal nucleation experiments with physiological saline solutions and leverage the statistical model to evaluate the natural variability of kinetic and thermodynamic nucleation parameters. By quantifying freezing probability as a function of temperature, supercooled duration, and system volume while accounting for nucleation site variability, this study also provides a basis for the rational design of stable supercooled biopreservation protocols.

The Influence of Solvent Selection upon the Crystallizability and Nucleation Kinetics of Tolfenamic Acid Form II.

The influence of the solution environment on the solution thermodynamics, crystallizability, and nucleation of tolfenamic acid (TFA) in five different solvents (isopropanol, ethanol, methanol, toluene, and acetonitrile) is examined using an integrated workflow encompassing both experimental studies and intermolecular modeling. The solubility of TFA in isopropanol is found to be the highest, consistent with the strongest solvent-solute interactions, and a concomitantly higher than ideal solubility. The crystallizability is found to be highly dependent on the solvent type with the overall order being isopropanol < ethanol < methanol < toluene < acetonitrile with the widest solution metastable zone width in isopropanol (24.49 to 47.41 °C) and the narrowest in acetonitrile (8.23 to 16.17 °C). Nucleation is found to occur via progressive mechanism in all the solvents studied. The calculated nucleation parameters reveal a considerably higher interfacial tension and larger critical nucleus radius in the isopropanol solutions, indicating the higher energy barrier hindering nucleation and hence lowering the nucleation rate. This is supported by diffusion coefficient measurements which are lowest in isopropanol, highlighting the lower molecular diffusion in the bulk of solution compared to the other solutions. The TFA concentration and critical supersaturation at the crystallization onset is found to be directly correlated with TFA/isopropanol solutions having the highest values of solubility and critical supersaturation. Intermolecular modeling of solute-solvent interactions supports the experimental observations of the solubility and crystallizability, highlighting the importance of understanding solvent selection and solution state structure at the molecular level in directing the solubility, solute mass transfer, crystallizability, and nucleation kinetics.

First-Principles Investigation of the Diffusion of TM and the Nucleation and Growth of L12 Al3TM Particles in Al Alloys

The key parameters of growth and nucleation of Al3TM particles (TM = Sc-Zn, Y-Cd and Hf-Hg) have been calculated using the combination of the first principles calculations with the quasi-harmonic approximation (QHA). Herein, the diffusion rate Ds of TM elements in Al is calculated using the diffusion activation energy Q, and the results show that the Ds of all impurity atoms increases logarithmically with the increase in temperature. With the increase in atomic number of TM, the Ds of 3–5d TM elements decreases linearly from Sc, Y and Hf to Mn, Ru and Ir, and then increases to Zn, Ag and Au, respectively. The interface energy γα/β, strain energy ΔEcs, chemical formation energy variation ΔGV and surface energy Esurave were further computed from the based interface and slab models, respectively. It was found that, with the increase in the atomic number of TM, the interface energies γα/β of Al/Al3TM (TM = (Sc-Zn, Y-Cd)) decreased from Sc and Y to Mn and Tc and then increased to Zn and Cd, respectively (except for the (001) plane of Al/Al3(Fe-Co), the (111) plane of Al/Al3Pd and the (110) and (111) planes of Al/Al3Cd). The strain energies ΔEcs of Al/Al3TM (TM = (Sc-Zn)) increased at first, and then decreased for all cycles. The chemical formation energy ΔGV of all Al3TM changed slightly in the temperature range of 0~1000 K, except that the ΔGV of Al3Sc, Al3Cu, Al3(Y-Zr), Al3Cd, Al3Hf and Al3Hg increased nonlinearly. With the increase in atomic number at both 300 and 600 K, the ΔGV of 3–5d TM elements increased from Sc, Y and Hf to Mn, Tc and Re at first, and then decreased to Co, Rh and Ir, respectively, and slightly changes at the end. With the increase in atomic number of TM, the variation trends of the surface energies of Al3TM intermetallic compounds present similar changes for all cycles, and the (111) surface always has the lowest values.

Effect of ultrafine recycled brick powder on the properties of blended cement: Hydration kinetics, microstructure evolution and properties development

Ultrafine grinding is expected to be an effective method to increase the pozzolanic activity of RBP, since RBP has superior grindability. The aim of this paper was to investigate the effects of 30 % ultrafine RBP with particle size of 8.6 μm, 4.5 μm, 3.6 μm and 2.7 μm on the fundamental properties, hydration kinetics and microstructure evolution of blended cement. The setting times, water requirement for normal consistency, rheological properties, hydration heat, hydration degree, mechanical strength and pore structure of cementitious material were evaluated. Results show that when 30 % RBP was added, the water requirement and viscosity of blended cement increased significantly with the decrease of RBP particle size, while the setting time was shortened due to the acceleration of early-age cement hydration. The parameters for the Boundary Nucleation and Growth (BNG) model indicate that the nucleation and growth rates of hydration products increased by 1.43 times and 1.27 times when RBP with D50 = 2.7 μm was added, thus the cement hydration degree reached more than 50 % in the first 72 h. Based on the thermogravimetric analysis (TGA), the pozzolanic reaction degree of ultrafine RBPs was more than 15 %–25 % depending on its size, and the hydration degree of cement in RBP-PC pastes was more than 80 %. As a result, blended cement mortars with up to 30 % ultrafine RBPs has slight or even no strength loss after curing for 90 days, as RBP-PC paste has a denser microstructure.

CNT effective interfacial energy and pre-exponential kinetic factor from measured NaCl crystal nucleation time distributions in contracting microdroplets.

Nucleation, the birth of a stable cluster from a disorder, is inherently stochastic. Yet up to date, there are no quantitative studies on NaCl nucleation that accounts for its stochastic nature. Here, we report the first stochastic treatment of NaCl-water nucleation kinetics. Using a recently developed microfluidic system and evaporation model, our measured interfacial energies extracted from a modified Poisson distribution of nucleation time show an excellent agreement with theoretical predictions. Furthermore, analysis of nucleation parameters in 0.5, 1.5, and 5.5 pl microdroplets reveals an interesting interplay between confinement effects and shifting of nucleation mechanisms. Overall, our findings highlight the need to treat nucleation stochastically rather than deterministically to bridge the gap between theory and experiment.