1
|
Nelson A, Friedman LH. Thermodynamically Stable Colloidal Solids: Interfacial Thermodynamics from the Particle Size Distribution. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:2161-2178. [PMID: 38881957 PMCID: PMC11177886 DOI: 10.1021/acs.jpcc.1c09365] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
True thermodynamic stability of a solid colloidal dispersion is generally unexpected, so much that thorough experimental validation of proposed stable systems remains incomplete. Such dispersions are under investigated and would be of interest due to their long-term stability and insensitivity to preparation pathway. We apply classical nucleation theory (CNT) to such colloidal systems, providing a relationship which links the size-dependent interfacial free energy density of the particles to their size distribution, and use this expression in the fitting of previously reported size distributions for putatively thermodynamically stable nanoparticles. Experimental data from a gold-thiol system exhibiting inverse coarsening or "digestive ripening" can be well-described in terms of a power-law dependence of the interfacial free energy γ on radius based on capacitive charging of the nanoparticles, going asr - 3 , as suggested by prior authors. Data from magnetite nanoparticles in highly basic solutions also can be well-fit using the CNT relation, but with γ going asr - 2 . Slightly better fits are possible if the power of the radius is non-integral, but we stress that more complex models of γ will require richer data sets to avoid the problem of overfitting. Some parameters of the fits are still robustly at odds with earlier models that implicitly assumed absolute thermodynamic stability: first, the extrapolated free energy density of the flat surface in these systems is small and positive, rather than strongly negative; second, the shape of the distributions indicates the solution phase to be supersaturated in monomer relative to the bulk, and thus that these two systems may only be metastable. For future work, we derive expressions for the important statistical thermodynamic and chemical parameters of the interface energy in terms of 1) the surfactant concentration, 2) the temperature dependence, and 3) the concentrations of particles in the tail of the distribution.
Collapse
Affiliation(s)
- Andrew Nelson
- Materials Measurement Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899
| | - Lawrence H Friedman
- Materials Measurement Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899
| |
Collapse
|
2
|
Di Trani N, Pimpinelli A, Grattoni A. Finite-Size Charged Species Diffusion and pH Change in Nanochannels. ACS APPLIED MATERIALS & INTERFACES 2020; 12:12246-12255. [PMID: 32068385 DOI: 10.1021/acsami.9b19182] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Molecular transport through nanofluidic structures exhibits properties that are unique at the nanoscale. The high surface-to-volume ratio of nanometer-sized confined spaces renders particle interactions with the surface of central importance. The electrical double layer (EDL) at the solid-liquid interface of charged surfaces generates an enrichment of counterions and the exclusion of co-ions that lead to a change in their diffusivity. In addition, the diffusive transport is altered by steric and hydrodynamic interactions between fluid molecules and the boundaries. An extensive body of literature investigates molecular transport at the nanoscale. However, most studies account for ionic species as point charges, severely limiting the applicability of the results to "large" nanofluidic systems. Moreover, and even more importantly, the change of pH in the nanoconfined region inside nanochannels has been completely overlooked. Corroborated by experimental data, here we present an all-encompassing analysis of molecular diffusion from the micro- to the ultra-nanoscale. While accounting for finite-size ions, we compute self-consistently the pH inside the channels. Surprisingly, we found that the concentration of ions H+ can change by more than 2 orders of magnitude compared to the bulk, hugely affecting molecular transport. Further, we found that counterions exhibit both enrichment and exclusion, depending on the size of nanochannels. Achieving a greater understanding of the effective transport properties of fluids at the nanoscale will fill the gap in knowledge that still limits development of innovative systems for medicine and industrial applications alike.
Collapse
Affiliation(s)
- Nicola Di Trani
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, Texas 77030, United States
- University of Chinese Academy of Science (UCAS), 19 Yuquan Road, Beijing 100049, Shijingshan, China
| | - Alberto Pimpinelli
- Smalley-Curl Institute and MSNE Department, Rice University, Houston, Texas 77005, United States
| | - Alessandro Grattoni
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, Texas 77030, United States
- Department of Surgery, Houston Methodist Hospital, Houston, Texas 77030, United States
- Department of Radiation Oncology, Houston Methodist Hospital, Houston, Texas 77030, United States
| |
Collapse
|
3
|
Caro MA, Laurila T, Lopez-Acevedo O. Accurate schemes for calculation of thermodynamic properties of liquid mixtures from molecular dynamics simulations. J Chem Phys 2017; 145:244504. [PMID: 28049340 DOI: 10.1063/1.4973001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We explore different schemes for improved accuracy of entropy calculations in aqueous liquid mixtures from molecular dynamics (MD) simulations. We build upon the two-phase thermodynamic (2PT) model of Lin et al. [J. Chem. Phys. 119, 11792 (2003)] and explore new ways to obtain the partition between the gas-like and solid-like parts of the density of states, as well as the effect of the chosen ideal "combinatorial" entropy of mixing, both of which have a large impact on the results. We also propose a first-order correction to the issue of kinetic energy transfer between degrees of freedom (DoF). This problem arises when the effective temperatures of translational, rotational, and vibrational DoF are not equal, either due to poor equilibration or reduced system size/time sampling, which are typical problems for ab initio MD. The new scheme enables improved convergence of the results with respect to configurational sampling, by up to one order of magnitude, for short MD runs. To ensure a meaningful assessment, we perform MD simulations of liquid mixtures of water with several other molecules of varying sizes: methanol, acetonitrile, N, N-dimethylformamide, and n-butanol. Our analysis shows that results in excellent agreement with experiment can be obtained with little computational effort for some systems. However, the ability of the 2PT method to succeed in these calculations is strongly influenced by the choice of force field, the fluidicity (hard-sphere) formalism employed to obtain the solid/gas partition, and the assumed combinatorial entropy of mixing. We tested two popular force fields, GAFF and OPLS with SPC/E water. For the mixtures studied, the GAFF force field seems to perform as a slightly better "all-around" force field when compared to OPLS+SPC/E.
Collapse
Affiliation(s)
- Miguel A Caro
- COMP Centre of Excellence in Computational Nanoscience, Department of Applied Physics, Aalto University, Espoo, Finland
| | - Tomi Laurila
- Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland
| | - Olga Lopez-Acevedo
- COMP Centre of Excellence in Computational Nanoscience, Department of Applied Physics, Aalto University, Espoo, Finland
| |
Collapse
|
4
|
Pascal TA, Goddard WA. Hydrophobic Segregation, Phase Transitions and the Anomalous Thermodynamics of Water/Methanol Mixtures. J Phys Chem B 2012; 116:13905-12. [DOI: 10.1021/jp309693d] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tod A. Pascal
- Materials
and Process Simulation
Center, California Institute of Technology, Pasadena, California 91125, United States
| | - William A Goddard
- Materials
and Process Simulation
Center, California Institute of Technology, Pasadena, California 91125, United States
- World Class University Professor, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
| |
Collapse
|
5
|
Sirota EB, Rangwalla H, Peczak P. Entropy of Mixing: Rigid vs Flexible Molecules: Effect of Varying Solvent on Dissolution Temperature. Macromolecules 2012. [DOI: 10.1021/ma202151g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- E. B. Sirota
- Corporate Strategic Research, ExxonMobil Research and Engineering Company, Route
22 East, Annandale, New Jersey 08801, United States
| | - H. Rangwalla
- Corporate Strategic Research, ExxonMobil Research and Engineering Company, Route
22 East, Annandale, New Jersey 08801, United States
- ExxonMobil Chemical Company, Baytown, Texas 77520, United States
| | - P. Peczak
- Corporate Strategic Research, ExxonMobil Research and Engineering Company, Route
22 East, Annandale, New Jersey 08801, United States
| |
Collapse
|
6
|
Bhuiyan GM, Alam MS, Ahmed AZZ, Syed IM, Rashid RIMA. Entropy of mixing for Ag(x)In(1-x) and Ag(x)Sn(1-x) liquid binary alloys. J Chem Phys 2009; 131:034502. [PMID: 19624204 DOI: 10.1063/1.3174448] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The entropy of mixing for Ag(x)In(1-x) and Ag(x)Sn(1-x) liquid binary alloys has been systematically investigated by using the perturbation theory. The interionic interactions as one of the basic ingredients are described by a local model pseudopotential. Since the metals forming the concerned alloys are less simple in nature the effect of the sp-d hybridization is appropriately taken into account through the interionic interactions. Results of our calculations across the full range of Ag concentrations are found to be good in agreement with the available experimental data.
Collapse
Affiliation(s)
- G M Bhuiyan
- Department of Theoretical Physics, University of Dhaka, Dhaka 1000, Bangladesh.
| | | | | | | | | |
Collapse
|
7
|
Both JA, Hong DC. Variational approach to hard sphere segregation under gravity. PHYSICAL REVIEW LETTERS 2002; 88:124301. [PMID: 11909464 DOI: 10.1103/physrevlett.88.124301] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2001] [Indexed: 05/23/2023]
Abstract
It is demonstrated that the minimization of the free energy functional for hard spheres and hard disks yields the result that excited granular materials under gravity segregate not only in the widely known "Brazil nut" fashion, i.e., with the larger particles rising to the top, but also in reverse "Brazil nut" fashion. Specifically, the local density approximation is used to investigate the crossover between the two types of segregation occurring in the liquid state, and the results are found to agree qualitatively with previously published results of simulation and of a simple model based on condensation.
Collapse
Affiliation(s)
- Joseph A Both
- Physics, Lewis Laboratory, Lehigh University, Bethlehem, Pennsylvania 18015, USA
| | | |
Collapse
|
8
|
Björling M, Pellicane G, Caccamo C. On the application of Flory–Huggins and integral equation theories to asymmetric hard sphere mixtures. J Chem Phys 1999. [DOI: 10.1063/1.479981] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
9
|
Sharp KA, Kumar S, Rossky PJ, Friedman RA, Honig B. Size Dependence of Transfer Free Energies. 2. Hard Sphere Models. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp960668t] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kim A. Sharp
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059
| | - Sanat Kumar
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Peter J. Rossky
- Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712
| | - Richard A. Friedman
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032
| | - Barry Honig
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032
| |
Collapse
|
10
|
|
11
|
Honnell KG, Hall CK. Theory and simulation of hard‐chain mixtures: Equations of state, mixing properties, and density profiles near hard walls. J Chem Phys 1991. [DOI: 10.1063/1.461772] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
12
|
Borkovec M. From micelles to microemulsion droplets: Size distributions, shape fluctuations, and interfacial tensions. J Chem Phys 1989. [DOI: 10.1063/1.457393] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
13
|
Borkovec M, Eicke HF, Ricka J. Polydispersity in dilute microemulsions: A consequence of the monomer-droplet equilibrium. J Colloid Interface Sci 1989. [DOI: 10.1016/0021-9797(89)90179-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|