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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Sculpting Liquids with Two-Dimensional Materials: The Assembly of Ti 3 C 2 T x MXene Sheets at Liquid–Liquid Interfaces

The self-assembly of nanoscale materials at the liquid-liquid interface allows for fabrication of three-dimensionally structured liquids with nearly arbitrary geometries and tailored electronic, optical, and magnetic properties. Two-dimensional (2D) materials are highly anisotropic, with thicknesses on the order of a nanometer and lateral dimensions upward of hundreds of nanometers to micrometers. Controlling the assembly of these materials has direct implications for their properties and performance. We here describe the interfacial assembly and jamming of Ti 3 C 2 T x MXene nanosheets at the oil-water interface. Planar, as well as complex, programmed three-dimensional all-liquid objects are realized. Finally, our approach presents potential for the creation of all-liquid 3D-printed devices for possible applications in all-liquid electrochemical and energy storage devices and electrically active, all-liquid fluidics that exploits the versatile structure, functionality, and reconfigurability of liquids.

2D materials↗
DOE OSTI2019

Some considerations on the water polymorphism and the liquid-liquid transition by the density behavior in the liquid phase

The bulk liquid water density data (ρ) are studied in a very large temperature pressure range including also the glass phases. A thorough analysis of their isobars, together with the suggestions of recent thermodynamical studies, gives evidence of two crossovers at T* and P* above which the hydrogen bond interaction is unable to arrange the tetrahedral network that is at the basis of the liquid polymorphism giving rise to the low density liquid (LDL). The curvatures of these isobars, as a function of T, are completely different: concave below P* (where maxima are) and convex above. In both the cases, a continuity between liquid and glass is observed with P* as the border of the density evolution toward the two different polymorphic glasses (low and high density amorphous). The experimental data of the densities of these two glasses also show a markedly different pressure dependence. Here, on the basis of these observations in bulk water and by considering a recent study on the growth of the LDL phase, by decreasing temperature, we discuss the water liquid-liquid transition and evaluate the isothermal compressibility inside the deep supercooled regime. Such a quantity shows an additional maximum that is pressure dependent that under ambient conditions agrees with a recent X-ray experiment. In particular, the present analysis suggests the presence of a liquid-liquid critical point located at about 180 MPa and 197 K.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Harnessing liquid-in-liquid printing and micropatterned substrates to fabricate 3-dimensional all-liquid fluidic devices

Systems comprised of immiscible liquids held in non-equilibrium shapes by the interfacial assembly and jamming of nanoparticle-polymer surfactants have crucial potential to advance catalysis, chemical separations, energy storage and conversion. Spatially directing functionality within them and coupling processes in both phases remains a challenge. In this work, we exploit nanoclay-polymer surfactant assemblies at an oil-water interface to produce a semi-permeable membrane between the liquids, and from them all-liquid fluidic devices with bespoke properties. Flow channels are fabricated using micropatterned 2D substrates and liquid-in-liquid 3D printing. The anionic walls of the device can be functionalized with cationic small molecules, enzymes, and colloidal nanocrystal catalysts. Multi-step chemical transformations can be conducted within the channels under flow, as can selective mass transport across the liquid-liquid interface for in-line separations. These all-liquid systems become automated using pumps, detectors, and control systems, revealing a latent ability for chemical logic and learning.

36 MATERIALS SCIENCE↗
DOE OSTI2023

X-ray imaging of liquid-liquid Mg cavitation

The coupling of dynamic loading platforms with synchrotron light sources have enabled experiments examining void formation in optically opaque materials. Much like spallation in a solid, cavitation occurs when rarefaction waves collide within a liquid. The resulting deformation leads to a complex flow field with numerous voids. It has been suggested that compaction of such a structure may be a significant source of ejecta (i.e. shallow bubble collapse). Experiments imaging supported and unsupported shocks interacting with a free surface in shock melted Mg with synchrotron radiation are presented. Here, the results are used to examine the structure of a cavitation plane that forms in the unsupported case and provide an estimate of the porosity within this region.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

Thermodynamic precursors, liquid-liquid transitions, dynamic and topological anomalies in densified liquid germania

The thermodynamic, dynamic, structural, and rigidity properties of densified liquid germania (GeO{sub 2}) have been investigated using classical molecular dynamics simulation. We construct from a thermodynamic framework an analytical equation of state for the liquid allowing the possible detection of thermodynamic precursors (extrema of the derivatives of the free energy), which usually indicate the possibility of a liquid-liquid transition. It is found that for the present germania system, such precursors and the possible underlying liquid-liquid transition are hidden by the slowing down of the dynamics with decreasing temperature. In this respect, germania behaves quite differently when compared to parent tetrahedral systems such as silica or water. We then detect a diffusivity anomaly (a maximum of diffusion with changing density/volume) that is strongly correlated with changes in coordinated species, and the softening of bond-bending (BB) topological constraints that decrease the liquid rigidity and enhance transport. The diffusivity anomaly is finally substantiated from a Rosenfeld-type scaling law linked to the pair correlation entropy, and to structural relaxation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Liquid–Liquid Mixing Studies in Annular Centrifugal Contactors Comparing Stationary Mixing Vane Options

Comparative studies of multiphase operation of annular centrifugal contactors showing the impact of housing stationary mixing vane configuration. A number of experimental results for several different mixing vane options are reported with selected measurements in a lab-scale 5 cm contactor and 12.5 cm engineering-scale unit. Fewer straight vanes give greater mixingzone hold-up compared to curved vanes. Quantitative comparison of droplet size distribution also showed a significant decrease in mean diameter for four straight vanes versus eight curved vanes. This set of measurements gives a compelling case for careful consideration of mixing vane geometry when evaluating hydraulic operation and extraction process efficiency of annular centrifugal contactors.

Wardle, Kent E.↗
DOE OSTI2026

From molecular to macroscopic: predicting liquid–liquid phase equilibria and small-angle scattering of mixtures of organic liquids from atomistic simulation using Kirkwood–Buff theory

Macroscopic phase equilibria between solutions define the functionality of many biological and industrial processes, yet they are challenging to predict due to the inherent complexity of liquids containing large molecules. This work introduces an approach for the purely predictive calculation of such phase equilibria in temperature-composition space from molecular dynamics (MD) simulations at one temperature in the single-phase region. We use an approach developed previously to obtain the entropic and enthalpic contributions to the free energy of mixing from the atomic-scale information given by MD simulations via Kirkwood–Buff theory. This allows us to accurately estimate the free energy of mixing as a function of temperature, and thus obtain liquid–liquid phase equilibria, including liquid–liquid critical points, associated binodal and spinodal lines, and composition fluctuations across a region of temperature and composition. Results for binary malonamide–alkane systems are validated by comparison to a direct experimental probe of the fluctuations: the small angle X-ray scattering intensity near zero wavenumber. The MDKB → Phase method demonstrated here provides a significant improvement in predicting liquid–liquid equilibria and free energy as a function of temperature for our systems of interest compared to conventional thermodynamic models. The accurate performance of this purely predictive approach lies in its preservation of atomistic details when determining thermodynamic properties. Furthermore, its inherent extensibility to multi-component systems will likely make the MDKB → Phase approach a valuable general tool for connecting molecular interactions to macroscopic phase equilibria and for the computational screening of materials for targeted thermodynamic behavior.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Influence of the Physical Properties of Liquids and Diameter of Bubble on the Formation of Liquid Column at the Interface of Two Liquid Phases by the Rising Bubble

The formation of metal emulsion in a steel-making process enhances the reaction between metal and slag. A part of the metal emulsion is formed by a bubble passing through the interface between the metal and slag phases. In a previous study, it was determined that the formation of metal column by the bubble is related to the formation of metal droplets. In this research, the effects of bubble particle size, interfacial tension, viscosity of upper layer, and lower layer density on the formation of lower liquid column were investigated. In order to conduct an in situ observation of gas and liquid behaviors, aqueous solution and silicon oil systems were employed. It was determined that a narrow and elongated column forms liquid droplets in the upper liquid layer and contributes to the formation of droplets. The height of the column and the volume of droplets increase with the increase in bubble size. The influence of interfacial tension of the two liquid phases on the column height and the formation of droplet is slight. The height of the formed column decreases with the increase in the density of lower liquid.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Selective Solid-liquid Extraction and Liquid-liquid Extraction of Lithium Chloride using Strapped Calix[4]pyrroles

LiCl is a classic "hard" ion salt that is present in lithium-rich brines and a key component in end-of-life materials (i.e., used lithium-ion batteries). Its isolation and purification from like salts is a recognized challenge with potential strategic and economic implications. Here in this paper, we describe two ditopic calix[4]pyrrole-based ion pair receptors (2 and 3), that are capable of selectively capturing LiCl. Under solid-liquid extraction conditions, using 2 as the extractant, LiCl could be separated from a NaCl-KCl salt mixture containing as little as 1% LiCl with ~100% selectivity, while receptor 3 achieved similar separations when the LiCl level was as low as 200 ppm. Under liquid-liquid extraction conditions using nitrobenzene as the non-aqueous phase, the extraction preference displayed by 2 is KCl > NaCl > LiCl. Lastly, in contrast, 3 exhibits high selectivity towards LiCl over NaCl and KCl, with no appreciable extraction being observed for the latter two salts.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Self-Assembly of MXene-Surfactants at Liquid–Liquid Interfaces: From Structured Liquids to 3D Aerogels

2D transition metal carbides and nitrides (MXenes), a class of emerging nanomaterials with intriguing properties, have attracted significant attention in recent years. However, owing to the highly hydrophilic nature of MXene nanosheets, assembly strategies of MXene at liquid-liquid interfaces have been very limited and challenging. Here in this paper, through the cooperative assembly of MXene and amine-functionalized polyhedral oligomeric silsesquioxane at the oil-water interface, we report the formation, assembly, and jamming of a new type MXene-based Janus-like nanoparticle surfactants, termed MXene-surfactants (MXSs), which can significantly enhance the interfacial activity of MXene nanosheets. More importantly, this simple assembly strategy opens a new platform for the fabrication of functional MXene assemblies from mesoscale (e.g., structured liquids) to macroscale (e.g., aerogels), that can be used for a range of applications, including nanocomposites, electronic devices, and all-liquid microfluidic devices.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗