1
|
Nie C, Geng J, Marlow WH. Formation free energy of an i-mer at spinodal. J Chem Phys 2021; 154:234108. [PMID: 34241258 DOI: 10.1063/5.0051879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In statistical mechanics, the formation free energy of an i-mer can be understood as the Gibbs free energy change in a system consisting of pure monomers after and prior to the formation of the i-mer. For molecules interacting via Lennard-Jones potential, we have computed the formation free energy of a Stillinger i-mer [F. H. Stillinger, J. Chem. Phys. 38, 1486 (1963)] and a ten Wolde-Frenkel (tWF) [P. R. ten Wolde and D. Frenkel, J. Chem. Phys. 109, 9901 (1998)] i-mer at spinodal at reduced temperatures from 0.7 to 1.2. It turns out that the size of a critical Stillinger i-mer remains finite and its formation free energy is on the order of kBT, and the size of a critical tWF i-mer remains finite and its formation free energy is even higher. This can be explained by Binder's theory [K. Binder, Phys. Rev. A 29, 341 (1984)] that for a system, when approaching spinodal, if the Ginzburg criterion is not satisfied, a gradual transition will take place from nucleation to spinodal decomposition, where the free-energy barrier height is on the order of kBT.
Collapse
Affiliation(s)
- Chu Nie
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Jun Geng
- State Power Investment Cooperation Hydrogen Energy Development Co., Ltd., South Park, Bejing Future Science & Technology Park, Beijing 100029, China
| | - William H Marlow
- Nuclear Engineering Department, Texas A&M University, 3133 TAMU, College Station, Texas 77843-3133, USA
| |
Collapse
|
2
|
Wyslouzil BE, Wölk J. Overview: Homogeneous nucleation from the vapor phase—The experimental science. J Chem Phys 2016; 145:211702. [DOI: 10.1063/1.4962283] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- Barbara E. Wyslouzil
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Judith Wölk
- Department of Chemistry, Physical Chemistry, Universität zu Köln, Luxemburger Str. 116, 50939 Köln, Germany
| |
Collapse
|
3
|
Ghosh D, Bergmann D, Schwering R, Wölk J, Strey R, Tanimura S, Wyslouzil BE. Homogeneous nucleation of a homologous series of n-alkanes (CiH2i+2, i=7–10) in a supersonic nozzle. J Chem Phys 2010; 132:024307. [DOI: 10.1063/1.3274629] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
4
|
Kalikmanov VI. Generalized Kelvin equation and pseudospinodal in nucleation theory. J Chem Phys 2008; 129:044510. [DOI: 10.1063/1.2958919] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
5
|
Iland K, Wölk J, Strey R, Kashchiev D. Argon nucleation in a cryogenic nucleation pulse chamber. J Chem Phys 2007; 127:154506. [DOI: 10.1063/1.2764486] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
6
|
Firanescu G, Hermsdorf D, Ueberschaer R, Signorell R. Large molecular aggregates: From atmospheric aerosols to drug nanoparticles. Phys Chem Chem Phys 2006; 8:4149-65. [PMID: 16971983 DOI: 10.1039/b608433h] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Large molecular aggregates with sizes ranging from subnanometers to microns are ubiquitous. As atmospheric aerosols they influence our climate, in interstellar space they are discussed as reactive sites, and in medicine small particles are considered as promising candidates to achieve a targeted drug delivery. The present contribution is focused on the characterization of the physical-chemical properties of these particles and on their targeted generation. One of the greatest challenges is to understand the properties of these aggregates on a molecular level. The latter point is discussed in detail focussing on the vibrational dynamics of these particles.
Collapse
Affiliation(s)
- George Firanescu
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
| | | | | | | |
Collapse
|
7
|
Signorell R, Jetzki M, Kunzmann M, Ueberschaer R. Unraveling the Origin of Band Shapes in Infrared Spectra of N2O−12CO2 and 12CO2−13CO2 Ice Particles. J Phys Chem A 2005; 110:2890-7. [PMID: 16509610 DOI: 10.1021/jp053021u] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Band structures in the region of strong infrared absorption bands for different N2O-12CO2 and 12CO2-13CO2 composite particles are investigated by combining quantum mechanical exciton calculations with systematic experimental investigations. The ice particles are generated by collisional cooling and characterized with rapid-scan infrared spectroscopy. The size of the particles lies between approximately 10 and 100 nm. The calculated spectra show excellent agreement with the experimental data. This work leads to a detailed understanding on a molecular level of shape effects in pure and statistically mixed particles as well as of the characteristic features observed for core-shell particles.
Collapse
Affiliation(s)
- Ruth Signorell
- Institut für Physikalische Chemie, Universität Göttingen, Tammannstrasse 6, D-37077 Göttingen, Germany.
| | | | | | | |
Collapse
|
8
|
Gharibeh M, Kim Y, Dieregsweiler U, Wyslouzil BE, Ghosh D, Strey R. Homogeneous nucleation of n-propanol, n-butanol, and n-pentanol in a supersonic nozzle. J Chem Phys 2005; 122:094512. [PMID: 15836155 DOI: 10.1063/1.1858438] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We have measured the nucleation conditions of n-propanol, n-butanol, and n-pentanol in a supersonic Laval nozzle, and estimated that the maximum nucleation rate J is 5 x 10(16) cm(-3) s(-1) with an uncertainty factor of 2. Plotting the vapor pressures p(J(max) ) and temperatures T(J(max) ) corresponding to the maximum nucleation rate as ln(p) versus 1T, produces a series of well separated straight lines. When these values are scaled by their respective critical parameters, p(c) and T(c), the data lie close to a single straight line. Comparing the experimental data to the predictions of classical nucleation theory reveals much higher experimental rates, and the deviation increases with increasing alcohol chain length and decreasing temperature. A scaling analysis in terms of Hale's scaled nucleation model [Phys. Rev. A 33, 4156 (1986); Metall. Trans. A 23, 1863 (1992)], clearly shows that our data are consistent with experimental nucleation rates measured using other devices that have characteristic rates many orders of magnitude lower.
Collapse
Affiliation(s)
- Murad Gharibeh
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609-2280, USA
| | | | | | | | | | | |
Collapse
|
9
|
Paci P, Zvinevich Y, Tanimura S, Wyslouzil BE, Zahniser M, Shorter J, Nelson D, McManus B. Spatially resolved gas phase composition measurements in supersonic flows using tunable diode laser absorption spectroscopy. J Chem Phys 2004; 121:9964-70. [PMID: 15549871 DOI: 10.1063/1.1807377] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We used a tunable diode laser absorption spectrometer to follow the condensation of D(2)O in a supersonic Laval nozzle. We measured both the concentration of the condensible vapor and the spectroscopic temperature as a function of position and compared the results to those inferred from static pressure measurements. Upstream and in the early stages of condensation, the quantitative agreement between the different experimental techniques is good. Far downstream, the spectroscopic results predict a lower gas phase concentration, a higher condensate mass fraction, and a higher temperature than the pressure measurements. The difference between the two measurement techniques is consistent with a slight compression of the boundary layers along the nozzle walls during condensation.
Collapse
Affiliation(s)
- Paolo Paci
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609-2280, USA
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Kim YJ, Wyslouzil BE, Wilemski G, Wölk J, Strey R. Isothermal Nucleation Rates in Supersonic Nozzles and the Properties of Small Water Clusters. J Phys Chem A 2004. [DOI: 10.1021/jp037030j] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yoo Jeong Kim
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609-2280, Department of Chemical Engineering, The Ohio State University, Columbus, Ohio 43210-1180, Department of Physics, University of MissouriRolla, Rolla, Missouri 65409-0640, and Institut für Physikalische Chemie, Universität zu Köln, 50939 Köln, Germany
| | - Barbara E. Wyslouzil
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609-2280, Department of Chemical Engineering, The Ohio State University, Columbus, Ohio 43210-1180, Department of Physics, University of MissouriRolla, Rolla, Missouri 65409-0640, and Institut für Physikalische Chemie, Universität zu Köln, 50939 Köln, Germany
| | - Gerald Wilemski
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609-2280, Department of Chemical Engineering, The Ohio State University, Columbus, Ohio 43210-1180, Department of Physics, University of MissouriRolla, Rolla, Missouri 65409-0640, and Institut für Physikalische Chemie, Universität zu Köln, 50939 Köln, Germany
| | - Judith Wölk
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609-2280, Department of Chemical Engineering, The Ohio State University, Columbus, Ohio 43210-1180, Department of Physics, University of MissouriRolla, Rolla, Missouri 65409-0640, and Institut für Physikalische Chemie, Universität zu Köln, 50939 Köln, Germany
| | - Reinhard Strey
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609-2280, Department of Chemical Engineering, The Ohio State University, Columbus, Ohio 43210-1180, Department of Physics, University of MissouriRolla, Rolla, Missouri 65409-0640, and Institut für Physikalische Chemie, Universität zu Köln, 50939 Köln, Germany
| |
Collapse
|
11
|
Wilemski G, Li JS. Nucleation near the spinodal: Limitations of mean field density functional theory. J Chem Phys 2004; 121:7821-8. [PMID: 15485244 DOI: 10.1063/1.1801273] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigate the diverging size of the critical nucleus near the spinodal using the gradient theory (GT) of van der Waals and Cahn and Hilliard and mean field density functional theory (MFDFT). As is well known, GT predicts that at the spinodal the free energy barrier to nucleation vanishes while the radius of the critical fluctuation diverges. We show numerically that the scaling behavior found by Cahn and Hilliard for these quantities holds quantitatively for both GT and MFDFT. We also show that the excess number of molecules Deltag satisfies Cahn-Hilliard scaling near the spinodal and is consistent with the nucleation theorem. From the latter result, it is clear that the divergence of Deltag is due to the divergence of the mean field isothermal compressibility of the fluid at the spinodal. Finally, we develop a Ginzburg criterion for the validity of the mean field scaling relations. For real fluids with short-range attractive interactions, the near-spinodal scaling behavior occurs in a fluctuation dominated regime for which the mean field theory is invalid. Based on the nucleation theorem and on Wang's treatment of fluctuations near the spinodal in polymer blends, we infer a finite size for the critical nucleus at the pseudospinodal identified by Wang.
Collapse
Affiliation(s)
- Gerald Wilemski
- Department of Physics and Cloud and Aerosol Sciences Laboratory, University of Missouri-Rolla, Rolla, MO 65409-0640, USA
| | | |
Collapse
|
12
|
Kunzmann MK, Bauerecker S, Suhm MA, Signorell R. Spectroscopic characterization of N(2)O aggregates: from clusters to the particulate state. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2003; 59:2855-2865. [PMID: 14499845 DOI: 10.1016/s1386-1425(03)00084-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Collisional cooling is used to generate N(2)O particles with radii ranging from the subnanometer to the submicrometer region. The vibrational dynamics of the aggregates is studied by Fourier transform infrared spectroscopy. In the region of the stretching fundamentals and combination bands, the infrared spectra of the particles exhibit characteristic size-dependent features. For the very small particles, the results obtained from collisional cooling are compared for the first time with corresponding results from supersonic jet expansions. It turns out that with both methods very similar clusters are generated. A pronounced temperature dependence of a combination band maximum in the collisional cooling cell spectra is found. This correlation is exploited to estimate cluster temperatures in supersonic jet spectra.
Collapse
Affiliation(s)
- M K Kunzmann
- Institut für Physikalische Chemie, Universität Göttingen, Tammannstr 6, D-37077 Göttingen, Germany
| | | | | | | |
Collapse
|
13
|
Khan A, Heath CH, Dieregsweiler UM, Wyslouzil BE, Strey R. Homogeneous nucleation rates for D2O in a supersonic Laval nozzle. J Chem Phys 2003. [DOI: 10.1063/1.1590640] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
14
|
Heath CH, Streletzky KA, Wyslouzil BE, Wölk J, Strey R. Small angle neutron scattering from D2O–H2O nanodroplets and binary nucleation rates in a supersonic nozzle. J Chem Phys 2003. [DOI: 10.1063/1.1554736] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
15
|
Wölk J, Strey R, Heath CH, Wyslouzil BE. Empirical function for homogeneous water nucleation rates. J Chem Phys 2002. [DOI: 10.1063/1.1498465] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|