1
|
Opdam J, Gandhi P, Kuhnhold A, Schilling T, Tuinier R. Excluded volume interactions and phase stability in mixtures of hard spheres and hard rods. Phys Chem Chem Phys 2022; 24:11820-11827. [PMID: 35508061 DOI: 10.1039/d2cp00477a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this paper we study excluded volume interactions, the free volume fraction available, and the phase behaviour, in mixtures of hard spheres (HS) and hard rods, modeled as spherocylinders. We use free volume theory (FVT) to predict various physical properties and compare to Monte Carlo computer simulations. FVT is used at two levels. We use the original FVT approach in which it is assumed that the correlations of the HS are not affected by the rods. This is compared to a recent, more rigorous, FVT approach which includes excluded volume interactions between the different components at all levels. We find that the novel rigorous FVT approach agrees well with computer simulation results at the level of free volume available, as well as for the phase stability. The FVT predictions show significant quantitative and qualitative deviations with respect to the original FVT approach. The phase transition curves are systematically at higher rod concentrations than previously predicted. Furthermore, the calculations revealed that a certain asphericity is required to induce isostructural fluid-fluid coexistence and the stability region is highly dependent on the size ratio between the rods and the spheres.
Collapse
Affiliation(s)
- Joeri Opdam
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, & Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, P. O. Box 513, 5600 MB, Eindhoven, The Netherlands.
| | - Poshika Gandhi
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany.
| | - Anja Kuhnhold
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany.
| | - Tanja Schilling
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany.
| | - Remco Tuinier
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, & Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, P. O. Box 513, 5600 MB, Eindhoven, The Netherlands.
| |
Collapse
|
2
|
Perini G, Avendaño C, Hicks W, Parsons AR, Vetter T. Predicting filtration of needle-like crystals: A Monte Carlo simulation study of polydisperse packings of spherocylinders. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2020.116151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
3
|
Thiyam P, Woodward CE, Forsman J. Non-monotonic phase behaviour of a mixture containing non-adsorbing particles and polymerising rod-like molecules. J Colloid Interface Sci 2020; 568:25-35. [PMID: 32078936 DOI: 10.1016/j.jcis.2020.02.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/05/2020] [Accepted: 02/06/2020] [Indexed: 10/25/2022]
Abstract
HYPOTHESIS Previous works have shown that many-body interactions induced by dispersants with increasing correlation length will generate a diminishing two-phase region [Soft Matter 14, 6921 (2018)]. We conjecture that the attenuation of the depletion attraction due to many-body interactions is a ubiquitous phenomenon in medium-induced interactions. We propose mixtures of colloidal particles and rod-like polymers as a feasible experimental system for verifying these predictions, since the intra-molecular correlations are not screened in a good solvent for rod-like polymers as they are in flexible polymers. The length of the rods can grow and become the dominant length scale that determines the range of the depletion interactions for the imbedded non-adsorbing particles. Simulations: We study many-body depletion forces induced by polymerizing rod-like polymers on spherical non-adsorbing colloids, using Metropolis Monte Carlo simulations. We also employ a simple mean-field theory to further justify our numerical predictions. FINDINGS We demonstrate that the phase diagram displays the same qualitative features that have previously been predicted by many-body theory, for mixtures containing flexible polymers under theta solvent conditions. The contraction of the particle two-phase region that we observe, as the correlation length increases beyond some specific value, could be a signature of the weakening of the depletion caused by many-body effects.
Collapse
Affiliation(s)
- Priyadarshini Thiyam
- Division of Theoretical Chemistry, Lund University, P. O. Box 124, SE-221 00 Lund, Sweden
| | - Clifford E Woodward
- School of Physical, Environmental and Mathematical Sciences, ADFA, Canberra, ACT 2600, Australia
| | - Jan Forsman
- Division of Theoretical Chemistry, Lund University, P. O. Box 124, SE-221 00 Lund, Sweden
| |
Collapse
|
4
|
Affiliation(s)
- Michael P. Allen
- Department of Physics, University of Warwick, Coventry, UK
- H. H. Wills Physics Laboratory, Royal Fort, Bristol, UK
| |
Collapse
|
5
|
Hatch HW, Mahynski NA, Murphy RP, Blanco MA, Shen VK. Monte Carlo simulation of cylinders with short-range attractions. AIP ADVANCES 2018; 8:095210. [PMID: 32855837 PMCID: PMC7448613 DOI: 10.1063/1.5040252] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/03/2018] [Indexed: 05/21/2023]
Abstract
Cylindrical or rod-like particles are promising materials for the applications of fillers in nanocomposite materials and additives to control rheological properties of colloidal suspensions. Recent advances in particle synthesis allows for cylinders to be manufactured with short-ranged attractions to study the gelation as a function of packing fraction, aspect ratio and attraction strength. In order to aid in the analysis of small-angle scattering experiments of rod-like particles, computer simulation methods were used to model these particles with specialized Monte Carlo algorithms and tabular superquadric potentials. The attractive interaction between neighboring rods increases with the amount of locally-accessible surface area, thus leading to patchy-like interactions. We characterize the clustering and percolation of cylinders as the attractive interaction increases from the homogenous fluid at relatively low attraction strength, for a variety of aspect ratios and packing fractions. Comparisons with the experimental scattering results are also presented, which are in agreement.
Collapse
Affiliation(s)
- Harold W. Hatch
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| | - Nathan A. Mahynski
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| | - Ryan P. Murphy
- Center for Neutron Science and Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, USA
| | - Marco A. Blanco
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland 20850, USA
| | - Vincent K. Shen
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| |
Collapse
|
6
|
Avendaño C, Jackson G, Wensink HH. Nanorings in planar confinement: the role of repulsive surfaces on the formation of lacuna smectics. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1484950] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Carlos Avendaño
- School of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - George Jackson
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Henricus H. Wensink
- Laboratoire de Physique des Solides UMR 8502, CNRS, Universite Paris-Sud, Universite Paris-Saclay, Orsay, France
| |
Collapse
|
7
|
Hvozd M, Patsahan T, Holovko M. Isotropic-Nematic Transition and Demixing Behavior in Binary Mixtures of Hard Spheres and Hard Spherocylinders Confined in a Disordered Porous Medium: Scaled Particle Theory. J Phys Chem B 2018; 122:5534-5546. [PMID: 29385800 DOI: 10.1021/acs.jpcb.7b11834] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We develop the scaled particle theory to describe the thermodynamic properties and orientation ordering of a binary mixture of hard spheres (HS) and hard spherocylinders (HSC) confined in a disordered porous medium. Using this theory, the analytical expressions of the free energy, the pressure, and the chemical potentials of HS and HSC have been derived. The improvement of obtained results is considered by introducing the Carnahan-Starling-like and Parsons-Lee-like corrections. Phase diagrams for the isotropic-nematic transition are calculated from the bifurcation analysis of the integral equation for the orientation singlet distribution function and from the conditions of thermodynamic equilibrium. Both the approaches correctly predict the isotropic-nematic transition at low concentrations of hard spheres. However, the thermodynamic approach provides more accurate results and is able to describe the demixing phenomena in the isotropic and nematic phases. The effects of porous medium on the isotropic-nematic phase transition and demixing behavior in a binary HS/HSC mixture are discussed.
Collapse
Affiliation(s)
- M Hvozd
- Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine , 1 Svientsitskii Street , 79011 Lviv , Ukraine
| | - T Patsahan
- Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine , 1 Svientsitskii Street , 79011 Lviv , Ukraine
| | - M Holovko
- Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine , 1 Svientsitskii Street , 79011 Lviv , Ukraine
| |
Collapse
|
8
|
Wu L, Malijevský A, Avendaño C, Müller EA, Jackson G. Demixing, surface nematization, and competing adsorption in binary mixtures of hard rods and hard spheres under confinement. J Chem Phys 2018; 148:164701. [DOI: 10.1063/1.5020002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Liang Wu
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Alexandr Malijevský
- Department of Physical Chemistry, University of Chemical Technology Prague, 166 28 Praha 6, Czech Republic
- Department of Microscopic and Mesoscopic Modelling, ICPF of the Czech Academy of Sciences, 165 02 Prague 6, Czech Republic
| | - Carlos Avendaño
- School of Chemical Engineering and Analytical Science, The University of Manchester, Sackville Street, Manchester M13 9PL, United Kingdom
| | - Erich A. Müller
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - George Jackson
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| |
Collapse
|
9
|
Wu L, Sun H. Cholesteric ordering predicted using a coarse-grained polymeric model with helical interactions. SOFT MATTER 2018; 14:344-353. [PMID: 29211101 DOI: 10.1039/c7sm02077e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The understanding of cholesteric liquid crystals at a molecular level is challenging. Limited insights are available to bridge between molecular structures and macroscopic chiral organization. In the present study, we introduce a novel coarse-grained (CG) molecular model, which is represented by flexible chain particles with helical interactions (FCh), to study the liquid crystalline phase behavior of cholesteric molecules such as double strand DNA and α-helix polypeptides using molecular dynamics (MD) simulations. The isotropic-cholesteric phase transitions of FCh molecules were simulated for varying chain flexibilities. A wall confinement was used to break the periodicity along the cholesteric helix director in order to predict the equilibrium cholesteric pitch. The left-handed cholesteric phase was shown for FCh molecules with right-handed chiral interactions, and a spatially inhomogeneous distribution of the nematic order parameter profile was observed in cholesteric phases. It was found that the chain flexibility plays an important role in determining the macroscopic cholesteric pitch and the structure of the cholesteric liquid crystal phase. The simulations provide insight into the relationship between microscopic molecular characteristics and the macroscopic phase behavior.
Collapse
Affiliation(s)
- Liang Wu
- School of Chemistry and Chemical Engineering, Key Laboratory of Scientific and Engineering Computing of Ministry of Education, Shanghai Jiao Tong University, 200240, Shanghai, China.
| | | |
Collapse
|
10
|
Viveros-Méndez PX, Gil-Villegas A, Aranda Espinoza S. Assessment by Monte Carlo computer simulations of the phase behavior of hard spherocylinders confined within cylindrical cavities. J Chem Phys 2017; 147:234902. [DOI: 10.1063/1.5017844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Perla X. Viveros-Méndez
- Unidad Académica de Física, Universidad Autónoma de Zacatecas, Calzada Solidaridad esq. Paseo, La Bufa s/n, 98060 Zacatecas, Zacatecas, México
| | - Alejandro Gil-Villegas
- Departamento de Ingeniería Física, División de Ciencias e Ingenierías Campus León, Universidad de Guanajuato, Loma del Bosque 103, Lomas del Campestre, 37150 León, Guanajuato, México
| | - Said Aranda Espinoza
- Instituto de Física ’Manuel Sandoval Vallarta’, Universidad Autónoma de San Luis Potosí, Álvaro Obregon 64, 78000 San Luis Potosí, SLP, México
| |
Collapse
|
11
|
Brumby PE, Wensink HH, Haslam AJ, Jackson G. Structure and Interfacial Tension of a Hard-Rod Fluid in Planar Confinement. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:11754-11770. [PMID: 28885848 DOI: 10.1021/acs.langmuir.7b02254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The structural properties and interfacial tension of a fluid of rodlike hard-spherocylinder particles in contact with hard structureless flat walls are studied by means of Monte Carlo simulation. The calculated surface tension between the rod fluid and the substrate is characterized by a nonmonotonic trend as a function of the bulk concentration (density) over the range of isotropic bulk concentrations. As suggested by earlier theoretical studies, a surface-ordering scenario is confirmed by our simulations: the local orientational order close to the wall changes from uniaxial to biaxial nematic when the bulk concentration reaches about 85% of the value at the onset of the isotropic-nematic phase transition. The surface ordering coincides with a wetting transition whereby the hard wall is wetted by a nematic film. Accurate values of the fluid-solid surface tension, the adsorption, and the average particle-wall contact distance are reported (over a broad range of densities into the dense nematic region for the first time), which can serve as a useful benchmark for future theoretical and experimental studies on confined rod fluids. The simulation data are supplemented with predictions from second-virial density functional theory, which are in good qualitative agreement with the simulation results.
Collapse
Affiliation(s)
- Paul E Brumby
- Department of Mechanical Engineering, Keio University , 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Henricus H Wensink
- Laboratoire de Physique des Solides, Université Paris Sud & CNRS , 91405 Orsay Cedex, France
| | - Andrew J Haslam
- Department of Chemical Engineering and Qatar Carbonates and Carbon Storage Research Centre, Imperial College London , South Kensington Campus, London SW7 2AZ, United Kingdom
| | - George Jackson
- Department of Chemical Engineering and Qatar Carbonates and Carbon Storage Research Centre, Imperial College London , South Kensington Campus, London SW7 2AZ, United Kingdom
| |
Collapse
|
12
|
Inokuchi T, Arai N. Liquid-crystal ordering mediated by self-assembly of surfactant solution confined in nanodroplet: a dissipative particle dynamics study. MOLECULAR SIMULATION 2017. [DOI: 10.1080/08927022.2017.1356459] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Takuya Inokuchi
- Department of Mechanical Engineering, Kindai University, Osaka, Japan
| | - Noriyoshi Arai
- Department of Mechanical Engineering, Kindai University, Osaka, Japan
| |
Collapse
|
13
|
Nascimento ES, Palffy-Muhoray P, Taylor JM, Virga EG, Zheng X. Density functional theory for dense nematic liquid crystals with steric interactions. Phys Rev E 2017; 96:022704. [PMID: 28950602 DOI: 10.1103/physreve.96.022704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Indexed: 06/07/2023]
Abstract
The celebrated work of Onsager on hard particle systems, based on the truncated second order virial expansion, is valid at relatively low volume fractions for large aspect ratio particles. While it predicts the isotropic-nematic phase transition, it does not provide a realistic equation of state in that the pressure remains finite for arbitrarily high densities. In this work, we derive a mean field density functional form of the Helmholtz free energy for nematics with hard core repulsion. In addition to predicting the isotropic-nematic transition, the model provides a more realistic equation of state. The energy landscape is much richer, and the orientational probability distribution function in the nematic phase possesses a unique feature-it vanishes on a nonzero measure set in orientation space.
Collapse
Affiliation(s)
| | | | - Jamie M Taylor
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
| | - Epifanio G Virga
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
| | - Xiaoyu Zheng
- Department of Mathematical Sciences, Kent State University, Kent, Ohio 44240, USA
| |
Collapse
|
14
|
Morgado P, Lobanova O, Müller EA, Jackson G, Almeida M, Filipe EJM. SAFT-γ force field for the simulation of molecular fluids: 8. Hetero-segmented coarse-grained models of perfluoroalkylalkanes assessed with new vapour–liquid interfacial tension data. Mol Phys 2016. [DOI: 10.1080/00268976.2016.1218077] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Pedro Morgado
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Olga Lobanova
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Erich A. Müller
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - George Jackson
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Miguel Almeida
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Eduardo J. M. Filipe
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| |
Collapse
|
15
|
Aliabadi R, Moradi M, Varga S. Tracking three-phase coexistences in binary mixtures of hard plates and spheres. J Chem Phys 2016; 144:074902. [DOI: 10.1063/1.4941981] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|