1
|
Pikina ES, Ostrovskii BI, Pikin SA. Coalescence of isotropic droplets in overheated free standing smectic films. SOFT MATTER 2020; 16:4591-4606. [PMID: 32365155 DOI: 10.1039/c9sm02292a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A theoretical study of the interaction and coalescence of isotropic droplets in overheated free-standing smectic films (FSSF) is presented. Experimentally it is clear that merging of such droplets is extremely rare. On the basis of the general thermodynamic approach to the stability of FSSF, we determined the energy gains and losses involved in the coalescence process. The main contributions to the critical work of drop coalescence are due to the gain related to the decrease of the surface energy of the merging drops, which is opposed by the entropic repulsions of elementary steps at the smectic interface between them. To quantify the evolution of the merging drops, we use a simple geometrical model in which the volume of the smectic material, rearranged in the process of coalescence, is described by an asymmetrical pyramid at the intersection of two drops. In this way, the critical work for drop coalescence and the corresponding energy barrier have been calculated. The probability of the thermal activation of the coalescence process was found to be negligibly small, indicating that droplet merging can be initiated by only an external stimulus. The dynamics of drop merging was calculated by equating the capillary force driving the coalescence, and the Stokes viscous force slowing it down. For the latter, an approximation of moving oblate spheroids permitting exact calculations was used. The time evolution of the height of the neck between the coalescing drops and that of their lateral size are in good agreement with experiments.
Collapse
Affiliation(s)
- Elena S Pikina
- Landau Institute for Theoretical Physics, Russian Academy of Sciences, pr. akademika Semenova 1-A, 142432 Chernogolovka, Russia.
| | | | | |
Collapse
|
2
|
Kovacik F, Okur HI, Smolentsev N, Scheu R, Roke S. Hydration mediated interfacial transitions on mixed hydrophobic/hydrophilic nanodroplet interfaces. J Chem Phys 2018; 149:234704. [PMID: 30579299 DOI: 10.1063/1.5035161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Interfacial phase transitions are of fundamental importance for climate, industry, and biological processes. In this work, we observe a hydration mediated surface transition in supercooled oil nanodroplets in aqueous solutions using second harmonic and sum frequency scattering techniques. Hexadecane nanodroplets dispersed in water freeze at a temperature of ∼15 °C below the melting point of the bulk alkane liquid. Addition of a trimethylammonium bromide (CXTA+) type surfactant with chain length equal to or longer than that of the alkane causes the bulk oil droplet freezing transition to be preceded by a structural interfacial transition that involves water, oil, and the surfactant. Upon cooling, the water loses some of its orientational order with respect to the surface normal, presumably by reorienting more parallel to the oil interface. This is followed by the surface oil and surfactant alkyl chains losing some of their flexibility, and this chain stretching induces alkyl chain ordering in the bulk of the alkane phase, which is then followed by the bulk transition occurring at a 3 °C lower temperature. This behavior is reminiscent of surface freezing observed in planar tertiary alkane/surfactant/water systems but differs distinctively in that it appears to be induced by the interfacial water and requires only a very small amount of surfactant.
Collapse
Affiliation(s)
- Filip Kovacik
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Halil I Okur
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Nikolay Smolentsev
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Rüdiger Scheu
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sylvie Roke
- Laboratory for fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| |
Collapse
|
3
|
Chen Q, Kozuch D, Milner ST. “Plunger” Method for Simulating Crystal–Melt Interfacial Free Energies. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00421] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Qin Chen
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Daniel Kozuch
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Scott T. Milner
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| |
Collapse
|
4
|
Pikina ES, Ostrovskii BI. Nucleation and growth of droplets in the overheated free-standing smectic films. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2017; 40:24. [PMID: 28247101 DOI: 10.1140/epje/i2017-11509-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 01/31/2017] [Indexed: 06/06/2023]
Abstract
We present a theoretical explanation for the formation of nematic droplets in free-standing smectic films (FSSF) overheated above the temperature of the bulk smectic - nematic transition. The conditions for the formation of the nematic droplets in smectic films are studied on the basis of the general thermodynamic approach to the stability of FSSF. It is shown that the formation of droplets in overheated FSSF is only possible in the presence of a certain amount of thermally generated dislocation loops. We determined the gain in the free energy related with the formation of the nematic droplets, the value of the critical work and the critical size of the drops. The initial increase of the drops size is due to release of material from the growing dislocation loops. At the second stage the drops growth occurs through coalescence of the smaller drops with the larger ones. The droplets attract each other by means of capillary forces arising due to gradients of the surface energy in the area between them. Drops size evolution, the dynamics of their growth and merging are in good agreement with experiments.
Collapse
Affiliation(s)
- Elena S Pikina
- Landau Institute for Theoretical Physics of the RAS, 142432, Chernogolovka, Russia.
- Oil and Gas Research Institute, Russian Academy of Sciences, Gubkin str. 3, 119333, Moscow, Russia.
| | - Boris I Ostrovskii
- Landau Institute for Theoretical Physics of the RAS, 142432, Chernogolovka, Russia
- FSRC "Crystallography and Photonics" of the RAS, Leninsky pr. 59, 119333, Moscow, Russia
| |
Collapse
|
5
|
Mukherjee PK. Effect of the liquid crystal solute on the rotator phase transitions of n-alkanes. RSC Adv 2015. [DOI: 10.1039/c4ra14116d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Recent experimental studies have shown that the liquid crystal substance plays an important role in determining the structures and the phase transitions of the different rotator phases in binary mixtures of n-alkane and liquid crystals.
Collapse
Affiliation(s)
- Prabir K. Mukherjee
- Department of Physics
- Government College of Engineering and Textile Technology
- Serampore, Hooghly-712201
- India
| |
Collapse
|
6
|
Su Y, Liu G, Xie B, Fu D, Wang D. Crystallization features of normal alkanes in confined geometry. Acc Chem Res 2014; 47:192-201. [PMID: 23947401 DOI: 10.1021/ar400116c] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
How polymers crystallize can greatly affect their thermal and mechanical properties, which influence the practical applications of these materials. Polymeric materials, such as block copolymers, graft polymers, and polymer blends, have complex molecular structures. Due to the multiple hierarchical structures and different size domains in polymer systems, confined hard environments for polymer crystallization exist widely in these materials. The confined geometry is closely related to both the phase metastability and lifetime of polymer. This affects the phase miscibility, microphase separation, and crystallization behaviors and determines both the performance of polymer materials and how easily these materials can be processed. Furthermore, the size effect of metastable states needs to be clarified in polymers. However, scientists find it difficult to propose a quantitative formula to describe the transition dynamics of metastable states in these complex systems. Normal alkanes [CnH2n+2, n-alkanes], especially linear saturated hydrocarbons, can provide a well-defined model system for studying the complex crystallization behaviors of polymer materials, surfactants, and lipids. Therefore, a deeper investigation of normal alkane phase behavior in confinement will help scientists to understand the crystalline phase transition and ultimate properties of many polymeric materials, especially polyolefins. In this Account, we provide an in-depth look at the research concerning the confined crystallization behavior of n-alkanes and binary mixtures in microcapsules by our laboratory and others. Since 2006, our group has developed a technique for synthesizing nearly monodispersed n-alkane containing microcapsules with controllable size and surface porous morphology. We applied an in situ polymerization method, using melamine-formaldehyde resin as shell material and nonionic surfactants as emulsifiers. The solid shell of microcapsules can provide a stable three-dimensional (3-D) confining environment. We have studied multiple parameters of these microencapsulated n-alkanes, including surface freezing, metastability of the rotator phase, and the phase separation behaviors of n-alkane mixtures using differential scanning calorimetry (DSC), temperature-dependent X-ray diffraction (XRD), and variable-temperature solid-state nuclear magnetic resonance (NMR). Our investigations revealed new direct evidence for the existence of surface freezing in microencapsulated n-alkanes. By examining the differences among chain packing and nucleation kinetics between bulk alkane solid solutions and their microencapsulated counterparts, we also discovered a mechanism responsible for the formation of a new metastable bulk phase. In addition, we found that confinement suppresses lamellar ordering and longitudinal diffusion, which play an important role in stabilizing the binary n-alkane solid solution in microcapsules. Our work also provided new insights into the phase separation of other mixed system, such as waxes, lipids, and polymer blends in confined geometry. These works provide a profound understanding of the relationship between molecular structure and material properties in the context of crystallization and therefore advance our ability to improve applications incorporating polymeric and molecular materials.
Collapse
Affiliation(s)
- Yunlan Su
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Guoming Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Baoquan Xie
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Dongsheng Fu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Dujin Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|
7
|
Rousseau D. Trends in structuring edible emulsions with Pickering fat crystals. Curr Opin Colloid Interface Sci 2013. [DOI: 10.1016/j.cocis.2013.04.009] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
8
|
Mukherjee PK. Tricritical behavior of the RI–RV rotator phase transition in a mixture of alkanes with nanoparticles. J Chem Phys 2011; 135:134505. [DOI: 10.1063/1.3646213] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
|
9
|
Fu D, Liu Y, Su Y, Liu G, Wang D. Crystallization Behavior of Binary Even−Even n-Alkane Mixtures in Microcapsules: Effect of Composition and Confined Geometry on Solid−Solid phase Separation. J Phys Chem B 2011; 115:4632-8. [DOI: 10.1021/jp2004248] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dongsheng Fu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- Graduate University of Chinese Academy of Sciences, Beijing 100190, China
| | - Yufeng Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yunlan Su
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Guoming Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- Graduate University of Chinese Academy of Sciences, Beijing 100190, China
| | - Dujin Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|
10
|
|
11
|
Fu D, Liu Y, Liu G, Su Y, Wang D. Confined crystallization of binary n-alkane mixtures: stabilization of a new rotator phase by enhanced surface freezing and weakened intermolecular interactions. Phys Chem Chem Phys 2011; 13:15031-6. [DOI: 10.1039/c1cp21281h] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
12
|
Black JK, Tracy LE, Roche CP, Henry PJ, Pesavento JB, Adalsteinsson T. Phase Transitions of Hexadecane in Poly(alkyl methacrylate) Core−Shell Microcapsules. J Phys Chem B 2010; 114:4130-7. [DOI: 10.1021/jp9080355] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jeremy K. Black
- Department of Chemistry and Biochemistry and Center for Nanostructures, Santa Clara University, Santa Clara, California 95053, and Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Lauren E. Tracy
- Department of Chemistry and Biochemistry and Center for Nanostructures, Santa Clara University, Santa Clara, California 95053, and Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Conor P. Roche
- Department of Chemistry and Biochemistry and Center for Nanostructures, Santa Clara University, Santa Clara, California 95053, and Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Paul J. Henry
- Department of Chemistry and Biochemistry and Center for Nanostructures, Santa Clara University, Santa Clara, California 95053, and Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Joseph B. Pesavento
- Department of Chemistry and Biochemistry and Center for Nanostructures, Santa Clara University, Santa Clara, California 95053, and Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Thorsteinn Adalsteinsson
- Department of Chemistry and Biochemistry and Center for Nanostructures, Santa Clara University, Santa Clara, California 95053, and Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| |
Collapse
|
13
|
Jiang K, Xie B, Fu D, Luo F, Liu G, Su Y, Wang D. Solid−Solid Phase Transition of n-Alkanes in Multiple Nanoscale Confinement. J Phys Chem B 2009; 114:1388-92. [DOI: 10.1021/jp9111475] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kai Jiang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Baoquan Xie
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Dongsheng Fu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Faliang Luo
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Guoming Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Yunlan Su
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Dujin Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| |
Collapse
|
14
|
Uniform discotic wax particles via electrospray emulsification. J Colloid Interface Sci 2009; 334:22-8. [DOI: 10.1016/j.jcis.2009.02.044] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2008] [Revised: 02/25/2009] [Accepted: 02/27/2009] [Indexed: 11/19/2022]
|
15
|
Jiang K, Su Y, Xie B, Meng Y, Wang D. Suppression of the Phase Separation in Binary n-Alkane Solid Solutions by Geometrical Confinement. J Phys Chem B 2009; 113:3269-72. [DOI: 10.1021/jp811496x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kai Jiang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, School of Chemistry and Materials Science, Ludong University, Yantai 264025, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Yunlan Su
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, School of Chemistry and Materials Science, Ludong University, Yantai 264025, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Baoquan Xie
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, School of Chemistry and Materials Science, Ludong University, Yantai 264025, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Yanfeng Meng
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, School of Chemistry and Materials Science, Ludong University, Yantai 264025, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Dujin Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, School of Chemistry and Materials Science, Ludong University, Yantai 264025, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| |
Collapse
|
16
|
Jiang K, Su Y, Xie B, Jiang S, Zhao Y, Wang D. Effect of Geometrical Confinement on the Nucleation and Crystallization Behavior of n-Alkane Mixtures. J Phys Chem B 2008; 112:16485-9. [DOI: 10.1021/jp807347d] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kai Jiang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Joint Laboratory for Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Yunlan Su
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Joint Laboratory for Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Baoquan Xie
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Joint Laboratory for Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Shichun Jiang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Joint Laboratory for Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Ying Zhao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Joint Laboratory for Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Dujin Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Engineering Plastics, Joint Laboratory for Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China, State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China, and Graduate School of Chinese Academy of Sciences, Beijing 100190, P. R. China
| |
Collapse
|
17
|
Bai XM, Li M. Comparing crystal-melt interfacial free energies through homogeneous nucleation rates. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2008; 20:375103. [PMID: 21694437 DOI: 10.1088/0953-8984/20/37/375103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this work, we compared several available crystal-melt interfacial free energies via homogeneous nucleation rates in a pure Lennard-Jones model system using both model fitting and numerical methods. We examined the homogeneous nucleation temperature obtained from the classical nucleation theory using the available interfacial free energies from three different methods as inputs, i.e. the free energy integration method, the interface fluctuation method and the classical nucleation theory based method. We found that the critical temperature obtained by using the interfacial free energy calculated recently (Bai and Li 2006 J. Chem. Phys. 124 124707) is in better agreement with that obtained from spontaneous crystallization in an independent molecular dynamics simulation. The discrepancies among the interface energies are discussed in light of these results.
Collapse
|
18
|
Fette EV, Pham A, Adalsteinsson T. Crystallization and Melting Transitions of Hexadecane Droplets in Polystyrene Nanocapsules. J Phys Chem B 2008; 112:5403-11. [DOI: 10.1021/jp7102879] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emily V. Fette
- Department of Chemistry, Santa Clara University, Santa Clara, California 95053
| | - Anthony Pham
- Department of Chemistry, Santa Clara University, Santa Clara, California 95053
| | | |
Collapse
|
19
|
Hearn JD, Smith GD. Ozonolysis of Mixed Oleic Acid/n-Docosane Particles: The Roles of Phase, Morphology, and Metastable States. J Phys Chem A 2007; 111:11059-65. [DOI: 10.1021/jp0755701] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- John D. Hearn
- Department of Chemistry, The University of Georgia, Athens, Georgia 30602
| | - Geoffrey D. Smith
- Department of Chemistry, The University of Georgia, Athens, Georgia 30602
| |
Collapse
|
20
|
Mukherjee PK. Landau model of the RII-RI-RV rotator phases in mixtures of alkanes. J Chem Phys 2007; 127:074901. [PMID: 17718631 DOI: 10.1063/1.2764483] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A phenomenological approach to the description of the rotator phases and transitions among them in mixtures of normal alkanes is proposed. The mixture exhibits crystal and three different rotator phases R(II), R(I), and R(V). The two phase regions are formed where the crystal+rotator and rotator+rotator phases coexist. The reason of these two phase regions is discussed by means of the Landau formalism. The influence of the concentration on these transitions and the transition temperatures are discussed by varying the coupling between the concentration variable and the order parameters. The theoretical predictions are found to be in good qualitative agreement with the experimental results.
Collapse
Affiliation(s)
- Prabir K Mukherjee
- Haldia Government College, P.O.-Debhog, District-Purba Medinipur 721657, India.
| |
Collapse
|
21
|
Affiliation(s)
- Eric B. Sirota
- Corporate Strategic Research, ExxonMobil Research and Engineering Company, Route 22 East, Annandale, New Jersey 08801
| |
Collapse
|
22
|
Xie B, Shi H, Jiang S, Zhao Y, Han CC, Xu D, Wang D. Crystallization Behaviors of n-Nonadecane in Confined Space: Observation of Metastable Phase Induced by Surface Freezing. J Phys Chem B 2006; 110:14279-82. [PMID: 16854133 DOI: 10.1021/jp063201j] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Crystallization and phase transition behaviors of n-nonadecane in microcapsules with a diameter of about 5 mum were studied with the combination of differential scanning calorimetry (DSC) and synchrotron radiation X-ray diffraction (XRD). As evident from the DSC measurement, a surface freezing monolayer, which is formed in the microcapsules before the bulk crystallization, induces a novel metastable rotator phase (R(II)), which has not been reported anywhere else. We argue that the existence of the surface freezing monolayer decreases the nucleating potential barrier of the R(II) phase and induces its appearance, while the lower free energy in the confined geometry turns the transient R(II) phase to a "long-lived" metastable phase.
Collapse
Affiliation(s)
- Baoquan Xie
- Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China
| | | | | | | | | | | | | |
Collapse
|
23
|
Shinohara Y, Kawasaki N, Ueno S, Kobayashi I, Nakajima M, Amemiya Y. Observation of the transient rotator phase of n-hexadecane in emulsified droplets with time-resolved two-dimensional small- and wide-angle X-ray scattering. PHYSICAL REVIEW LETTERS 2005; 94:097801. [PMID: 15784000 DOI: 10.1103/physrevlett.94.097801] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Indexed: 05/15/2023]
Abstract
Crystallization of n-hexadecane in emulsion droplets was studied using time-resolved two-dimensional small- and wide-angle x-ray scattering with differential scanning calorimetry (2D-SAXS-WAXS-in situ DSC) which provides information about both nano- and subnanoscale structural change. n-hexadecane in droplets reproducibly crystallized into the stable triclinic phase via a transient-rotator phase. This is in contrast with previous results that the rotator phase of n-hexadecane was observed only occasionally for bulk samples. Thus we confirmed the existence of rotator phase in n-hexadecane, which is important for the study of crystallization of soft materials. We suggest that the rotator phase at the interface of oil and water plays a precursor role for bulk crystallization. This study demonstrates that 2D-SAXS-WAXS-in situ DSC is a powerful tool for the study of a transient phase.
Collapse
Affiliation(s)
- Yuya Shinohara
- Department of Advanced Materials Science, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8561, Japan.
| | | | | | | | | | | |
Collapse
|
24
|
Sloutskin E, Bain CD, Ocko BM, Deutsch M. Surface freezing of chain molecules at the liquid–liquid and liquid–air interfaces. Faraday Discuss 2005; 129:339-52; discussion 353-66. [PMID: 15715317 DOI: 10.1039/b405969g] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Surface freezing (SF) is the formation of a crystalline monolayer at the free surface of a melt at a temperature Ts, a few degrees above the bulk freezing temperature, Tb. This effect, i.e. Ts > Tb, common to many chain molecules, is in a marked contrast with the surface melting effect, i.e. Ts < or = Tb, shown by almost all other materials. Depending on chain length, n, the SF layer shows a variety of phases, in some cases tuneable by bulk additives. The SF behaviour of binary mixtures of different-length alkanes and alcohols is governed by the relative chain length mismatch, /delta n/n/2, yielding a quasi-"universal" behaviour for the freezing of both bulk and surface. While SF at the liquid air interface was studied rather extensively, Lei and Bain (Phys. Rev. Lett., 2004, 94, 176103) have shown only very recently that interfacial freezing (IF) can be induced also at the water: tetradecane interface by adding the ionic surfactant CTAB to the water phase. We present measurements of the interfacial tension of the water: hexadecane interface, as a function of temperature and the ionic surfactant STAB, revealing IF at a STAB-concentration-dependent temperature Ti > Tb. The measurements indicate that a single frozen monolayer is formed, with a temperature-existence range of up to 10 degrees C, much larger than the 1.2 degrees C found for SF at the free surface of the melt. We also find a new effect, where the IF allows tuning of the interfacial tension between the two bulk phases to zero for a range of temperatures, deltaT = Tmix - Tb < or = Ti - Tb by cooling the system below Ti. We discuss qualitatively the factors stabilizing the frozen layer and their variation from the liquid-air to the liquid-liquid interfaces. The surfactant concentration dependence of Ti is also discussed and a tentative theoretical explanation is suggested.
Collapse
Affiliation(s)
- Eli Sloutskin
- Physics Department, Bar-Ilan University, Ramat-Gan 52900, Israel
| | | | | | | |
Collapse
|