Zheng Tang, Fangyuan Ma, Feng Li, Yugui Yao, Di Zhou
Topological surface states are unique to topological materials and are immune to disturbances. In isostatic lattices, mechanical topological floppy modes exhibit softness depending on the polarization relative to the terminating surface. However, in three dimensions, the polarization of topological floppy modes is disrupted by the ubiquitous mechanical Weyl lines. Here, we demonstrate, both theoretically and experimentally, the fully-polarized topological mechanical phases free of Weyl lines. Floppy modes emerge exclusively on a particular surface of the three-dimensional isostatic structure, leading to the strongly asymmetric stiffness between opposing boundaries. Additionally, uniform soft strains can reversibly shift the lattice configuration to Weyl phases, reducing the stiffness contrast to a trivially comparable level. Our work demonstrates the fully-polarized topological mechanical phases in three dimensions, and paves the way towards engineering soft and adaptive metamaterials.
{"title":"Fully-Polarized Topological Isostatic Metamaterials in Three Dimensions","authors":"Zheng Tang, Fangyuan Ma, Feng Li, Yugui Yao, Di Zhou","doi":"arxiv-2409.02607","DOIUrl":"https://doi.org/arxiv-2409.02607","url":null,"abstract":"Topological surface states are unique to topological materials and are immune\u0000to disturbances. In isostatic lattices, mechanical topological floppy modes\u0000exhibit softness depending on the polarization relative to the terminating\u0000surface. However, in three dimensions, the polarization of topological floppy\u0000modes is disrupted by the ubiquitous mechanical Weyl lines. Here, we\u0000demonstrate, both theoretically and experimentally, the fully-polarized\u0000topological mechanical phases free of Weyl lines. Floppy modes emerge\u0000exclusively on a particular surface of the three-dimensional isostatic\u0000structure, leading to the strongly asymmetric stiffness between opposing\u0000boundaries. Additionally, uniform soft strains can reversibly shift the lattice\u0000configuration to Weyl phases, reducing the stiffness contrast to a trivially\u0000comparable level. Our work demonstrates the fully-polarized topological\u0000mechanical phases in three dimensions, and paves the way towards engineering\u0000soft and adaptive metamaterials.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
James Utama Surjadi, Bastien F. G. Aymon, Molly Carton, Carlos M. Portela
Mechanical metamaterials are renowned for their ability to achieve high stiffness and strength at low densities, often at the expense of low ductility and stretchability-a persistent trade-off in materials. In contrast, materials such as double-network hydrogels feature interpenetrating compliant and stiff polymer networks, and exhibit unprecedented combinations of high stiffness and stretchability, resulting in exceptional toughness. Here, we present double-network-inspired (DNI) metamaterials by integrating monolithic truss (stiff) and woven (compliant) components into a metamaterial architecture, which achieve a tenfold increase in stiffness and stretchability compared to their pure woven and truss counterparts, respectively. Nonlinear computational mechanics models elucidate that enhanced energy dissipation in these DNI metamaterials stems from increased frictional dissipation due to entanglements between the two networks. Through introduction of internal defects, which typically degrade mechanical properties, we demonstrate an opposite effect of a threefold increase in energy dissipation for these metamaterials via failure delocalization. This work opens avenues for developing new classes of metamaterials in a high-compliance regime inspired by polymer network topologies.
机械超材料以其在低密度下实现高刚度和高强度的能力而闻名于世，但其代价往往是低延展性和拉伸性--这是材料领域长期存在的权衡问题。与此相反，双网络水凝胶等材料具有相互渗透的顺应性和刚性聚合物网络，展现出前所未有的高刚性和高拉伸性组合，从而产生卓越的韧性。在这里，我们通过将单片桁架（刚性）和编织（顺应性）组件集成到超材料结构中，展示了受双网络启发（DNI）的超材料，与纯编织和桁架组件相比，其刚性和拉伸性分别提高了十倍。非线性计算力学模型阐明，这些 DNI 超材料中能量耗散的增强源于两个网络之间的缠结导致摩擦耗散的增加。通过引入通常会降低机械性能的内部缺陷，我们证明了一种相反的效果，即通过失效定位，这些超材料的能量耗散增加了三倍。这项工作为在聚合物网络结构的启发下开发新类型的高顺应性超材料开辟了道路。
{"title":"Double-network-inspired mechanical metamaterials","authors":"James Utama Surjadi, Bastien F. G. Aymon, Molly Carton, Carlos M. Portela","doi":"arxiv-2409.01533","DOIUrl":"https://doi.org/arxiv-2409.01533","url":null,"abstract":"Mechanical metamaterials are renowned for their ability to achieve high\u0000stiffness and strength at low densities, often at the expense of low ductility\u0000and stretchability-a persistent trade-off in materials. In contrast, materials\u0000such as double-network hydrogels feature interpenetrating compliant and stiff\u0000polymer networks, and exhibit unprecedented combinations of high stiffness and\u0000stretchability, resulting in exceptional toughness. Here, we present\u0000double-network-inspired (DNI) metamaterials by integrating monolithic truss\u0000(stiff) and woven (compliant) components into a metamaterial architecture,\u0000which achieve a tenfold increase in stiffness and stretchability compared to\u0000their pure woven and truss counterparts, respectively. Nonlinear computational\u0000mechanics models elucidate that enhanced energy dissipation in these DNI\u0000metamaterials stems from increased frictional dissipation due to entanglements\u0000between the two networks. Through introduction of internal defects, which\u0000typically degrade mechanical properties, we demonstrate an opposite effect of a\u0000threefold increase in energy dissipation for these metamaterials via failure\u0000delocalization. This work opens avenues for developing new classes of\u0000metamaterials in a high-compliance regime inspired by polymer network\u0000topologies.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Celso CarrascoUC San Diego, Quentin MartinetIST Austria, Zaiyi ShenLOMA, Juho S. LintuvuoriLOMA, Jérémie PalacciIST Austria, Antoine AubretLOMA
Catalytic microswimmers convert the chemical energy of a fuel into motion, sustaining spatial chemical gradients and fluid flows that drive their propulsion. This leads to unconventional individual behavior and the emergence of collective dynamics, absent in equilibrium. The characterization of the nonequilibrium interactions driven by those concentration gradients and flows around microswimmers is challenging owing to the importance of fluctuations at the microscale. Previous experiments have focused on large Janus microspheres attached to a surface, and did not investigate non-equilibrium interactions for freely moving microswimmers of various shapes. Here we show a massive dependence of the non-equilibrium interactions on the shape of small catalytic microswimmers. We perform tracking experiments at high troughput to map non-equilibrium interactions between swimmers and colloidal tracers in 2D, accurate down to tracer velocity of 100nm/s. In addition, we devise a novel experimental method combining two types of tracers with differing phoretic mobility to disentangle phoretic interactions in concentration gradients from hydrodynamic flows. We benchmark the method with experiments on a single chemically active site and on a catalytic microswimmer tethered to a surface. We further investigate the activity-driven interactions of freely moving catalytic dimers as microswimmers, for a wide range of aspect ratio between the active and passive part. We confront our results with standard theoretical models of microswimmers near surfaces and show poor agreement, ruling out phoresis as the main interaction for catalytic swimmers. Our findings provide robust quantitative measurements of the non-equilibrium interactions of catalytic microswimmers of various geometry with their environment. The work notably indicates the need for theoretical development, and lays the groundwork for the quantitative description of collective behavior in suspensions of phoretically-driven colloidal suspensions.
{"title":"Quantitative measurements of non-equilibrium interactions of catalytic microswimmers with dual colloidal tracers","authors":"Celso CarrascoUC San Diego, Quentin MartinetIST Austria, Zaiyi ShenLOMA, Juho S. LintuvuoriLOMA, Jérémie PalacciIST Austria, Antoine AubretLOMA","doi":"arxiv-2409.01024","DOIUrl":"https://doi.org/arxiv-2409.01024","url":null,"abstract":"Catalytic microswimmers convert the chemical energy of a fuel into motion,\u0000sustaining spatial chemical gradients and fluid flows that drive their\u0000propulsion. This leads to unconventional individual behavior and the emergence\u0000of collective dynamics, absent in equilibrium. The characterization of the\u0000nonequilibrium interactions driven by those concentration gradients and flows\u0000around microswimmers is challenging owing to the importance of fluctuations at\u0000the microscale. Previous experiments have focused on large Janus microspheres\u0000attached to a surface, and did not investigate non-equilibrium interactions for\u0000freely moving microswimmers of various shapes. Here we show a massive\u0000dependence of the non-equilibrium interactions on the shape of small catalytic\u0000microswimmers. We perform tracking experiments at high troughput to map\u0000non-equilibrium interactions between swimmers and colloidal tracers in 2D,\u0000accurate down to tracer velocity of 100nm/s. In addition, we devise a novel\u0000experimental method combining two types of tracers with differing phoretic\u0000mobility to disentangle phoretic interactions in concentration gradients from\u0000hydrodynamic flows. We benchmark the method with experiments on a single\u0000chemically active site and on a catalytic microswimmer tethered to a surface.\u0000We further investigate the activity-driven interactions of freely moving\u0000catalytic dimers as microswimmers, for a wide range of aspect ratio between the\u0000active and passive part. We confront our results with standard theoretical\u0000models of microswimmers near surfaces and show poor agreement, ruling out\u0000phoresis as the main interaction for catalytic swimmers. Our findings provide\u0000robust quantitative measurements of the non-equilibrium interactions of\u0000catalytic microswimmers of various geometry with their environment. The work\u0000notably indicates the need for theoretical development, and lays the groundwork\u0000for the quantitative description of collective behavior in suspensions of\u0000phoretically-driven colloidal suspensions.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Colloidal Solids (COLIS) is a state-of-the-art light scattering setup developed for experiments onboard the International Space Station (ISS). COLIS allows for probing the structure and dynamics of soft matter systems on a wide range of length scales, from a few nm to tens of microns, and on time scales from 100 ns to tens of hours. In addition to conventional static and dynamic light scattering, COLIS includes depolarized dynamic light scattering, a small-angle camera, photon correlation imaging, and optical manipulation of thermosensitive samples through an auxiliary near-infrared laser beam, thereby providing a unique platform for probing soft matter systems. We demonstrate COLIS through ground tests on standard Brownian suspensions, and on protein, colloidal glasses, and gel systems similar to those to be used in future ISS experiments.
{"title":"COLIS: an advanced light scattering apparatus for investigating the structure and dynamics of soft matter onboard the International Space Station","authors":"Alessandro Martinelli, Stefano Buzzaccaro, Quentin Galand, Juliette Behra, Niel Segers, Erik Leussink, Yadvender Singh Dhillon, Dominique Maes, James Lutsko, Roberto Piazza, Luca Cipelletti","doi":"arxiv-2409.01189","DOIUrl":"https://doi.org/arxiv-2409.01189","url":null,"abstract":"Colloidal Solids (COLIS) is a state-of-the-art light scattering setup\u0000developed for experiments onboard the International Space Station (ISS). COLIS\u0000allows for probing the structure and dynamics of soft matter systems on a wide\u0000range of length scales, from a few nm to tens of microns, and on time scales\u0000from 100 ns to tens of hours. In addition to conventional static and dynamic\u0000light scattering, COLIS includes depolarized dynamic light scattering, a\u0000small-angle camera, photon correlation imaging, and optical manipulation of\u0000thermosensitive samples through an auxiliary near-infrared laser beam, thereby\u0000providing a unique platform for probing soft matter systems. We demonstrate\u0000COLIS through ground tests on standard Brownian suspensions, and on protein,\u0000colloidal glasses, and gel systems similar to those to be used in future ISS\u0000experiments.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Semicrystalline polymers (SCP) represent important class of materials used in many applications from packaging to transportation to electronics to pharmaceuticals. Understanding the structure and dynamics of the crystalline and amorphous fractions within SCP is an important challenge for both experimentalists and theoreticians. Recently, Cheng et al. (S. Cheng et al., J. Chem. Phys. 160, 114904 (2024)) utilized Broadband Dielectric Spectroscopy (BDS) to explore the relaxation time profiles within the amorphous region of a semi-crystalline poly(L-lactic acid) (PLLA) with ordered alternative stacking of crystalline/amorphous phases. Here, we build on those initial results and model the relaxation time distribution using the combination of the Doolittle free volume theory (FVT) and the compressible Self-Consistent Field Theory (cSCFT). We show that the new modeling framework successfully captures the temperature and position dependence of the local relaxation time of the semicrystalline PLLA above the glass transition temperature of the amorphous region. Finally, we derive a new empirical equation for the relaxation time profiles in amorphous regions of SCPs.
{"title":"Modeling the Dielectric Relaxation in Semicrystalline Polymers -- Understanding the Role of the Interphase between the Amorphous and Crystalline Domains","authors":"Valeriy V. Ginzburg","doi":"arxiv-2409.01471","DOIUrl":"https://doi.org/arxiv-2409.01471","url":null,"abstract":"Semicrystalline polymers (SCP) represent important class of materials used in\u0000many applications from packaging to transportation to electronics to\u0000pharmaceuticals. Understanding the structure and dynamics of the crystalline\u0000and amorphous fractions within SCP is an important challenge for both\u0000experimentalists and theoreticians. Recently, Cheng et al. (S. Cheng et al., J.\u0000Chem. Phys. 160, 114904 (2024)) utilized Broadband Dielectric Spectroscopy\u0000(BDS) to explore the relaxation time profiles within the amorphous region of a\u0000semi-crystalline poly(L-lactic acid) (PLLA) with ordered alternative stacking\u0000of crystalline/amorphous phases. Here, we build on those initial results and\u0000model the relaxation time distribution using the combination of the Doolittle\u0000free volume theory (FVT) and the compressible Self-Consistent Field Theory\u0000(cSCFT). We show that the new modeling framework successfully captures the\u0000temperature and position dependence of the local relaxation time of the\u0000semicrystalline PLLA above the glass transition temperature of the amorphous\u0000region. Finally, we derive a new empirical equation for the relaxation time\u0000profiles in amorphous regions of SCPs.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Agitated granular media have a rich rheology: they exhibit Newtonian behavior at low shear rate and density, develop a yield stress at high density, and cross over to Bagnoldian shear thickening when sheared rapidly -- making them challenging to encompass in one theoretical framework. We measure the rheology of air-fluidized glass particles, spanning five orders of magnitude in shear rate, and show that all rheological regimes can be delineated by two dimensionless numbers. We propose a constitutive relation that captures all flow behaviors, qualitatively and quantitatively, in one unified framework.
{"title":"Rheological regimes in agitated granular media under shear","authors":"Olfa D'Angelo, Matthias Sperl, W. Till Kranz","doi":"arxiv-2409.01297","DOIUrl":"https://doi.org/arxiv-2409.01297","url":null,"abstract":"Agitated granular media have a rich rheology: they exhibit Newtonian behavior\u0000at low shear rate and density, develop a yield stress at high density, and\u0000cross over to Bagnoldian shear thickening when sheared rapidly -- making them\u0000challenging to encompass in one theoretical framework. We measure the rheology\u0000of air-fluidized glass particles, spanning five orders of magnitude in shear\u0000rate, and show that all rheological regimes can be delineated by two\u0000dimensionless numbers. We propose a constitutive relation that captures all\u0000flow behaviors, qualitatively and quantitatively, in one unified framework.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For the first time, the crystal structure of the Kob-Andersen mixture has been probed by genetic algorithms calculations. The stable structures of the system with different molar fractions of the components have been identified and their stability at finite temperature has been verified. A possibility to obtain these structures by spontaneous crystallization of a liquid has been checked.
{"title":"Kob-Andersen model crystal structure: genetic algorithms vs spontaneous crystallization","authors":"Yu. D. Fomin, N. M. Chtchelkatchev","doi":"arxiv-2409.00710","DOIUrl":"https://doi.org/arxiv-2409.00710","url":null,"abstract":"For the first time, the crystal structure of the Kob-Andersen mixture has\u0000been probed by genetic algorithms calculations. The stable structures of the\u0000system with different molar fractions of the components have been identified\u0000and their stability at finite temperature has been verified. A possibility to\u0000obtain these structures by spontaneous crystallization of a liquid has been\u0000checked.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":"185 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142227384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lukas J. Roemling, Gaia De Angelis, Annika Mauch, Esther Amstad, Nicolas Vogel
Clusters of colloidal particles, often termed supraparticles, can provide more functionality than the individual particles they consist of. Since these functionalities are determined by the arrangement of the primary particles within a supraparticle, controlling the structure formation process is of fundamental importance. Here, we show how buckling is determined by particle-surfactant interactions and how the final morphology of the formed supraparticles can be controlled by manipulating these interactions in time. We use water/oil emulsions to template supraparticle formation and tailor the interactions of negatively charged colloidal particles with the surfactants stabilizing the water/oil-interface via the local pH within the aqueous droplet. At low pH, protonation of the anionic headgroup of the surfactant decreases electrostatic repulsion of the particles, facilitates interfacial adsorption, and subsequently causes buckling. We show that the local pH of the aqueous phase continuously changes during the assembly process. We gain control over the formation pathway by determining the point in time when interfacial adsorption is enabled, which we control via the initial pH. As a consequence, the final supraparticle morphology can be tailored at will, from fully buckled structures, via undulated surface morphologies to spherically rough and spherically smooth supraparticles and crystalline colloidal clusters.
{"title":"Control of Buckling of Colloidal Supraparticles","authors":"Lukas J. Roemling, Gaia De Angelis, Annika Mauch, Esther Amstad, Nicolas Vogel","doi":"arxiv-2409.00602","DOIUrl":"https://doi.org/arxiv-2409.00602","url":null,"abstract":"Clusters of colloidal particles, often termed supraparticles, can provide\u0000more functionality than the individual particles they consist of. Since these\u0000functionalities are determined by the arrangement of the primary particles\u0000within a supraparticle, controlling the structure formation process is of\u0000fundamental importance. Here, we show how buckling is determined by\u0000particle-surfactant interactions and how the final morphology of the formed\u0000supraparticles can be controlled by manipulating these interactions in time. We\u0000use water/oil emulsions to template supraparticle formation and tailor the\u0000interactions of negatively charged colloidal particles with the surfactants\u0000stabilizing the water/oil-interface via the local pH within the aqueous\u0000droplet. At low pH, protonation of the anionic headgroup of the surfactant\u0000decreases electrostatic repulsion of the particles, facilitates interfacial\u0000adsorption, and subsequently causes buckling. We show that the local pH of the\u0000aqueous phase continuously changes during the assembly process. We gain control\u0000over the formation pathway by determining the point in time when interfacial\u0000adsorption is enabled, which we control via the initial pH. As a consequence,\u0000the final supraparticle morphology can be tailored at will, from fully buckled\u0000structures, via undulated surface morphologies to spherically rough and\u0000spherically smooth supraparticles and crystalline colloidal clusters.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nicolás A. Loubet, Alejandro R. Verde, Gustavo A. Appignanesi
The peculiar structuring of liquid water stems from a fine-tuned molecular principle embodying the two different interaction demands of the water molecule: The formation of hydrogen bonds or the compensation for coordination defects. Here we shall show that the same underlying molecular mechanism is also at play in order to establish favorable interactions with other systems. In this regard, the emergence of two limiting behaviors for hydrophilicity will help both to unravel its molecular underpinnings and to establish absolute values for such property.
{"title":"The nature of water interactions and the molecular signatures of hydrophilicity","authors":"Nicolás A. Loubet, Alejandro R. Verde, Gustavo A. Appignanesi","doi":"arxiv-2409.00437","DOIUrl":"https://doi.org/arxiv-2409.00437","url":null,"abstract":"The peculiar structuring of liquid water stems from a fine-tuned molecular\u0000principle embodying the two different interaction demands of the water\u0000molecule: The formation of hydrogen bonds or the compensation for coordination\u0000defects. Here we shall show that the same underlying molecular mechanism is\u0000also at play in order to establish favorable interactions with other systems.\u0000In this regard, the emergence of two limiting behaviors for hydrophilicity will\u0000help both to unravel its molecular underpinnings and to establish absolute\u0000values for such property.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iván M. Zerón, Jesús Algaba, José Manuel Míguez, Bruno Mendiboure, Felipe J. Blas
Averaged local bond order parameters based on spherical harmonics, also known as Lechner and Dellago order parameters, are routinely used to determine crystal structures in molecular simulations. Among different options, the combination of the $overline{q}_{4}$ and $overline{q}_{6}$ parameters is one of the best choices in the literature since allows one to distinguish, not only between solid- and liquid-like particles but also between different crystallographic phases, including cubic and hexagonal phases. Recently, Algaba et al. [J. Colloid Interface Sci. 623, 354, (2022)] have used the Lechner and Dellago order parameters to distinguish hydrate- and liquid-like water molecules in the context of determining the carbon dioxide hydrate-water interfacial free energy. According to the results, the preferred combination previously mentioned is not the best option to differentiate between hydrate- and liquid-like water molecules. In this work, we revisit and extend the use of these parameters to deal with systems in which clathrate hydrates phases coexist with liquid phases of water. We consider carbon dioxide, methane, tetrahydrofuran, nitrogen, and hydrogen hydrates that exhibit sI and sII crystallographic structures. We find that the $overline{q}_{3}$ and $overline{q}_{12}$ combination is the best option possible between a large number of possible different pairs to distinguish between hydrate- and liquid-like water molecules in all cases.
{"title":"Rotationally invariant local bond order parameters for accurate determination of hydrate structures","authors":"Iván M. Zerón, Jesús Algaba, José Manuel Míguez, Bruno Mendiboure, Felipe J. Blas","doi":"arxiv-2409.00508","DOIUrl":"https://doi.org/arxiv-2409.00508","url":null,"abstract":"Averaged local bond order parameters based on spherical harmonics, also known\u0000as Lechner and Dellago order parameters, are routinely used to determine\u0000crystal structures in molecular simulations. Among different options, the\u0000combination of the $overline{q}_{4}$ and $overline{q}_{6}$ parameters is one\u0000of the best choices in the literature since allows one to distinguish, not only\u0000between solid- and liquid-like particles but also between different\u0000crystallographic phases, including cubic and hexagonal phases. Recently, Algaba\u0000et al. [J. Colloid Interface Sci. 623, 354, (2022)] have used the Lechner and\u0000Dellago order parameters to distinguish hydrate- and liquid-like water\u0000molecules in the context of determining the carbon dioxide hydrate-water\u0000interfacial free energy. According to the results, the preferred combination\u0000previously mentioned is not the best option to differentiate between hydrate-\u0000and liquid-like water molecules. In this work, we revisit and extend the use of\u0000these parameters to deal with systems in which clathrate hydrates phases\u0000coexist with liquid phases of water. We consider carbon dioxide, methane,\u0000tetrahydrofuran, nitrogen, and hydrogen hydrates that exhibit sI and sII\u0000crystallographic structures. We find that the $overline{q}_{3}$ and\u0000$overline{q}_{12}$ combination is the best option possible between a large\u0000number of possible different pairs to distinguish between hydrate- and\u0000liquid-like water molecules in all cases.","PeriodicalId":501146,"journal":{"name":"arXiv - PHYS - Soft Condensed Matter","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142220667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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