1
|
Sorina PO, Victorov AI. Local Structure of Nonuniform Fluid Mixtures Containing Associating and Chainlike Molecules from a Multilayer Quasichemical Model. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:1577-1593. [PMID: 38198683 DOI: 10.1021/acs.langmuir.3c01741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
In this work, we develop a theory for predicting details of the local structure in nonuniform multicomponent fluids that may contain chainlike and associating components. This theory is an extension─to the fluid interfaces and mesoscopic structures of different geometry─of the multilayer quasichemical model originally proposed by Smirnova to describe liquid solution in the vicinity of a planar solid wall. The basis of the theory is the "cut-and-bond" approach, much in spirit of SAFT, where an infinite attraction between the separated monomeric units of a chainlike molecule mimics the chemical bonds of the chain. We describe the equilibrium structure of the mixture, including the spatial distribution of the monomeric units and the local orientation of the chemical bonds in chainlike molecules, and discuss the contribution of chemical bonds to the local chemical potential in a nonuniform fluid. To test the new theory, we apply it to mixtures containing combinations of model components: a strongly associating solvent, an inert substance of varying chain length, and a chainlike amphiphile. To compare predictions from the multilayer model with the results of continuous description of nonuniform fluids, we also address the square-gradient theory and derive an analytical expression for the influence parameter that takes into account pair correlations in the quasichemical approximation. The multilayer quasichemical model developed in this work predicts formation of aggregates in liquid solution and describes the local structure of the interfaces between the coexisting liquid phases in the mixture. Our theoretical predictions agree on a qualitative level with the accumulated knowledge about the structure of different types of systems studied in this work.
Collapse
Affiliation(s)
- Polina O Sorina
- St. Petersburg State University, 7/9 Universitetskaya nab., 199034 St. Petersburg, Russia
| | - Alexey I Victorov
- St. Petersburg State University, 7/9 Universitetskaya nab., 199034 St. Petersburg, Russia
| |
Collapse
|
2
|
Lu J, González de Castilla A, Müller S, Xi S, Chapman WG. Dualistic Role of Alcohol in Micelle Formation and Structure from iSAFT Based Density Functional Theory and COSMOplex. Ind Eng Chem Res 2023. [DOI: 10.1021/acs.iecr.2c03507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Jinxin Lu
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas77005, United States
| | | | - Simon Müller
- Institute of Thermal Separation Processes, Hamburg University of Technology, Hamburg21073, Germany
| | - Shun Xi
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas77005, United States
| | - Walter G. Chapman
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas77005, United States
- Institute of Thermal Separation Processes, Hamburg University of Technology, Hamburg21073, Germany
| |
Collapse
|
3
|
Rehner P, van Westen T, Gross J. Equation of state and Helmholtz energy functional for fused heterosegmented hard chains. Phys Rev E 2022; 105:034110. [PMID: 35428149 DOI: 10.1103/physreve.105.034110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/18/2022] [Indexed: 06/14/2023]
Abstract
Modern equations of state for real nonspherical molecules are often based on Wertheim's first-order thermodynamic perturbation theory (TPT1). A major drawback of TPT1 is that it assumes tangentially bonded spheres. In this work, we develop a Helmholtz energy functional for systems comprising hard heterosegmented chains with arbitrary bond lengths. This is achieved by using hard-sphere fragments (i.e., hard spheres with spherical caps removed at the intersection to their neighbors) as monomers as opposed to full hard spheres. The model is written as a Helmholtz energy functional for inhomogeneous systems and the equation of state for a homogeneous system is determined as a special case. We thereby obtain an equation of state that can be used as a reference to develop statistical associating fluid theory models that more accurately describe the thermodynamic properties of nonspherical molecules. The model is validated against molecular simulation results of bulk pressures and density profiles in slit pores. For the bulk pressures, we show that the equation of state is in excellent agreement with results from molecular simulation for dimers, trimers, and chains of up to 20 segments. The density profiles of individual segments of the chains are regarded in slit pores. Some deviations of the theory from results of molecular simulations are observed for strongly fused chains. Overall, however, good agreement is found for inhomogeneous systems.
Collapse
Affiliation(s)
- Philipp Rehner
- Energy and Process Systems Engineering, Department of Mechanical and Process Engineering, ETH Zurich, Tannenstrasse 3, 8092 Zurich, Switzerland
- Institute of Thermodynamics and Thermal Process Engineering, University of Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart, Germany
| | - Thijs van Westen
- Institute of Thermodynamics and Thermal Process Engineering, University of Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart, Germany
| | - Joachim Gross
- Institute of Thermodynamics and Thermal Process Engineering, University of Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart, Germany
| |
Collapse
|
4
|
The branching angle effect on the properties of rigid dendrimers studied by Monte Carlo simulation. J Mol Model 2021; 27:144. [PMID: 33931800 DOI: 10.1007/s00894-021-04767-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/20/2021] [Indexed: 10/21/2022]
Abstract
We studied the properties of rigid dendrimers with different branching angles by means of Monte Carlo simulations on a coarse-grained level. It was found that the terminal groups of dendrimers with both rigid and flexible spacers could locate near the center of the molecule. In flexible dendrimers, the wide distribution is attributed to the back folding of flexible spacers, while in rigid dendrimers, it is caused by the branching angle effect that a branch will grow laterally due to the restriction of a non-zero branching angle. It has been established that the branching angle is a key parameter for rigid dendrimers, which can be applied to tune the properties of rigid dendrimers: decreasing branching angle is helpful to obtain dendrimers with a larger size, lower density, and more terminal groups locating at periphery.
Collapse
|
5
|
Rehner P, Bursik B, Gross J. Surfactant Modeling Using Classical Density Functional Theory and a Group Contribution PC-SAFT Approach. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c00169] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Philipp Rehner
- Institute of Thermodynamics and Thermal Process Engineering, University of Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart, Germany
| | - Benjamin Bursik
- Institute of Thermodynamics and Thermal Process Engineering, University of Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart, Germany
| | - Joachim Gross
- Institute of Thermodynamics and Thermal Process Engineering, University of Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart, Germany
| |
Collapse
|
6
|
Zhang Y, Xi S, Parambathu AV, Chapman WG. Density functional study of one- and two-component bottlebrush molecules in solvents of varying quality. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1767812] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Yuchong Zhang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Shun Xi
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | | | - Walter G. Chapman
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| |
Collapse
|
7
|
Xi S, Liu J, Valiya Parambathu A, Zhang Y, Chapman WG. An Efficient Algorithm for Molecular Density Functional Theory in Cylindrical Geometry: Application to Interfacial Statistical Associating Fluid Theory (iSAFT). Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.9b06895] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shun Xi
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Jinlu Liu
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Arjun Valiya Parambathu
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Yuchong Zhang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Walter G. Chapman
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| |
Collapse
|
8
|
Zhang Y, Chapman WG. Modeling Lower Critical Solution Temperature Behavior of Associating Dendrimers Using Density Functional Theory. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10808-10817. [PMID: 31335155 DOI: 10.1021/acs.langmuir.9b00514] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We study the phase behavior of associating dendrimers in explicit solvents using classical density functional theory. The existence of association enables uptake of solvent inside the dendrimer even for unfavorable Lennard-Jones interaction between the solvent and dendrimer. Depending on the distributions of associating sites, the dendrimer conformation can be either dense-core or dense-shell. The conformation of the associating dendrimer is greatly affected by the temperature. Due to the interplay between association interaction and Lennard-Jones attractions, we find the lower critical solution temperature (LCST) behavior of dendrimer conformation and study how it changes as the dendrimer size or solvent size changes. The dendrimer in our study displays no LCST behavior at low generations, and it has a maximum LCST at G4. Moreover, increasing the solvent chain length decreases the LCST. For solvents with self-association, the competition between solvent-solvent association and solvent-dendrimer association also tends to reduce the LCST. Qualitatively consistent with experiments, our results provide insight into the molecular mechanism of the LCST behavior of associating dendrimers.
Collapse
Affiliation(s)
- Yuchong Zhang
- Department of Chemical and Biomolecular Engineering , Rice University , 6100 Main Street , Houston , Texas 77005 , United States
| | - Walter G Chapman
- Department of Chemical and Biomolecular Engineering , Rice University , 6100 Main Street , Houston , Texas 77005 , United States
| |
Collapse
|
9
|
Liu J, Xi S, Chapman WG. Competitive Sorption of CO 2 with Gas Mixtures in Nanoporous Shale for Enhanced Gas Recovery from Density Functional Theory. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:8144-8158. [PMID: 31030516 DOI: 10.1021/acs.langmuir.9b00410] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
CO2 competitive sorption with shale gas under various conditions from simple to complex pore characteristics is studied using a molecular density functional theory (DFT) that reduces to perturbed chain-statistical associating fluid theory in the bulk fluid region. The DFT model is first verified by grand canonical Monte Carlo simulation in graphite slit pores for pure and binary component systems at different temperatures, pressures, pore sizes, and bulk gas compositions for methane/ethane with CO2. Then, the model is utilized in multicomponent systems that include CH4, C2H6, and C3+ components of different compositions. It is shown that the selectivity of CO2 decreases with increases in temperature, pressure, nanopore size, and average molecular weight of shale gas. Extending the model to more realistic situations, we consider the impact of water present in the pore and consider the effect of permeation of fluid molecules into the kerogen that forms the pore walls. The water-graphite interaction is calibrated with contact angle from molecular simulation data from the literature. The kerogen pore model prediction of gas absolute sorption is compared with experimental and molecular simulation values in the literature. It is shown that the presence of water reduces the CO2 adsorption but improves the CO2 selectivity. The dissolution of gases into the kerogen matrix also leads to the increase in CO2 selectivity. The effect of kerogen type and maturity on the gas sorption amount and CO2 selectivity is also studied. The associated mechanisms are discussed to provide fundamental understanding for gas recovery by CO2.
Collapse
Affiliation(s)
- Jinlu Liu
- Department of Chemical and Biomolecular Engineering , Rice University , 6100 Main Street , Houston , Texas 77005 , United States
| | - Shun Xi
- Department of Chemical and Biomolecular Engineering , Rice University , 6100 Main Street , Houston , Texas 77005 , United States
| | - Walter G Chapman
- Department of Chemical and Biomolecular Engineering , Rice University , 6100 Main Street , Houston , Texas 77005 , United States
| |
Collapse
|
10
|
Xi S, Wang L, Liu J, Chapman W. Thermodynamics, Microstructures, and Solubilization of Block Copolymer Micelles by Density Functional Theory. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:5081-5092. [PMID: 30855146 DOI: 10.1021/acs.langmuir.8b04336] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Block copolymer micelle is one of the most versatile self-assembled structures with applications in drug delivery, cosmetic products, and micellar-enhanced ultrafiltration. The key to design an effective block copolymer to form micelles is to understand how molecular architecture affects critical micelle concentrations, micellar dimensions, and partitioning of solute into the micelle. In this work, we studied micelles from nonionic block copolymers using interfacial statistical associating fluid theory a density functional theory, which explicitly includes block copolymer-water hydrogen bonding and water-water hydrogen bonding. We are able to predict and explain how micellar thermodynamic properties depend on polymer chain architecture. Dimension and aggregation of micelles are investigated for block copolymers with different hyrophobes and hydrophiles. The effects of temperature and pressure on micelle stability are also captured by the theory. The enhanced solubility of hydrophobic substance in water by micelle loading is demonstrated, and predicted solute distribution answers the question about the locus of benzene in micelles from a theoretical perspective.
Collapse
Affiliation(s)
- Shun Xi
- Department of Chemical and Biomolecular Engineering , Rice University , Houston , Texas 77005 , United States
| | - Le Wang
- Department of Chemical and Biomolecular Engineering , Rice University , Houston , Texas 77005 , United States
| | - Jinlu Liu
- Department of Chemical and Biomolecular Engineering , Rice University , Houston , Texas 77005 , United States
| | - Walter Chapman
- Department of Chemical and Biomolecular Engineering , Rice University , Houston , Texas 77005 , United States
| |
Collapse
|
11
|
Wengenmayr M, Dockhorn R, Sommer JU. Dendrimers in Solution of Linear Polymers: Crowding Effects. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Martin Wengenmayr
- Leibniz Institute
of Polymer Research Dresden, Hohe Strasse 6, 01069 Dresden, Germany
| | - Ron Dockhorn
- Leibniz Institute
of Polymer Research Dresden, Hohe Strasse 6, 01069 Dresden, Germany
| | - Jens-Uwe Sommer
- Leibniz Institute
of Polymer Research Dresden, Hohe Strasse 6, 01069 Dresden, Germany
- Institute for Theoretical Physics, Technische Universität Dresden, 01069 Dresden, Germany
| |
Collapse
|
12
|
Sokołowski S, Pizio O. Density functional approach to the description of the structure of dimer nanoparticles at liquid–liquid interfaces. Phys Chem Chem Phys 2019; 21:11181-11192. [DOI: 10.1039/c9cp01087d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A density functional approach to the description of the structure of dimer nanoparticles at liquid–liquid interfaces.
Collapse
Affiliation(s)
- Stefan Sokołowski
- Department for the Modelling of Physico-Chemical Processes
- Maria Curie-Sklodowska University
- Lublin 20-031
- Poland
| | - Orest Pizio
- Instituto de Química
- Universidad Nacional Autónoma de México
- Circuito Exterior
- Mexico
| |
Collapse
|
13
|
Trejos VM, Pizio O, Sokołowski S. Towards the description of adsorption of water in slit-like pores with walls covered by molecular brushes. J Chem Phys 2018; 149:234703. [PMID: 30579295 DOI: 10.1063/1.5066552] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The density profiles, adsorption isotherms, and phase behavior of a water model in a slit-like pore with walls modified by pre-adsorbed tethered chain molecules have been studied in the framework of a density functional theory. Each chain is bonded to the surface by its terminal segment, and the surface density of grafted chains is the same for each wall. The model for water taken from the work of Clark et al. [Mol. Phys. 104, 3561 (2006)] reproduces successfully a bulk equation of state. The mean field approach has been used to describe the effects of attractive interactions. The chemical association effects are taken into account by using the first-order thermodynamic perturbation theory of Wertheim. We have found that the presence of molecular brushes on the pore walls has important consequences for the adsorption and phase behavior of confined water. If the brush segments do not attract water molecules strongly, the vapor-liquid coexistence envelope shrinks upon increasing brush density, but the critical temperature is weakly affected. Alteration from capillary condensation to evaporation is observed with changes in the brush density, number of segments of tethered chains, and/or chemical identity of segments. The crossover temperature is affected by all these factors. Moreover, we have shown that affinity of water to segments of tethers is an important factor determining adsorption of water vapor and the entire phase diagram.
Collapse
Affiliation(s)
- Víctor M Trejos
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, 04510 Ciudad de México, Mexico
| | - Orest Pizio
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, 04510 Ciudad de México, Mexico
| | - Stefan Sokołowski
- Department for the Modelling of Physico-Chemical Processes, Maria Curie-Skłodowska University, Lublin 20-031, Poland
| |
Collapse
|