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Full-Text Articles in Physical Sciences and Mathematics
Monte Carlo Simulation Of Vapor–Liquid Binodal Of Water, S. Yoo, Xiao Cheng Zeng
Monte Carlo Simulation Of Vapor–Liquid Binodal Of Water, S. Yoo, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
Among many popular potential models of water, the nonpolarizable four-site TIP4P potential is one of the more widely used. Recently, two new potential models of water on the basis of the TIP4P potential have been developed. One is the four-site Dang–Chang polarizable potential and another is the five-site TIP5P potential. The former is designed to describe not only bulk and interfacial properties of liquid water but also microclusters of water. The nonpolarizable TIP5P potential is the latest version in the TIP series from the Jorgensen group. Compared with the TIP4P potential, for example, the TIP5P potential gives a much improved …
Effect Of An Electric Field On The Surface Tension Of A Dipolar-Quadrupolar Fluid And Its Implication For Sign Preference In Droplet Nucleation, V.B. Warshavsky, Xiao Cheng Zeng
Effect Of An Electric Field On The Surface Tension Of A Dipolar-Quadrupolar Fluid And Its Implication For Sign Preference In Droplet Nucleation, V.B. Warshavsky, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
The effect of a uniform electric field on interfacial properties of dipolar-quadrupolar fluids is investigated by using the density-functional theory. As in the case of purely dipolar fluids the (thermodynamic) surface tension is always altered by the external field, regardless of the direction of the field. However, unlike the purely dipolar fluids, for two given external fields with the same strength but exactly opposite direction the magnitude of variation in the surface tension is different. This apparent symmetry breaking by reversing the field direction suggests a new molecular mechanism to explain the phenomenon of sign preference in droplet formation on …
Creating Nanocavities Of Tunable Sizes: Hollow Helices, Bing Gong, Huaqiang Zeng, Jin Zhu, Lihua Yuan, Yaohua Han, Shizhi Cheng, Mako Furukawa, Ruben D. Parra, Audrey Y. Kovalevsky, Jeffrey L. Mills, Ewa Skrzypczak-Jankun, Suzana Martinovic, Richard D. Smith, Chong Zheng, Thomas Szyperski, Xiao Cheng Zeng
Creating Nanocavities Of Tunable Sizes: Hollow Helices, Bing Gong, Huaqiang Zeng, Jin Zhu, Lihua Yuan, Yaohua Han, Shizhi Cheng, Mako Furukawa, Ruben D. Parra, Audrey Y. Kovalevsky, Jeffrey L. Mills, Ewa Skrzypczak-Jankun, Suzana Martinovic, Richard D. Smith, Chong Zheng, Thomas Szyperski, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
A general strategy for creating nanocavities with tunable sizes based on the folding of unnatural oligomers is presented. The backbones of these oligomers are rigidified by localized, threecenter intramolecular hydrogen bonds, which lead to well-defined hollow helical conformations. Changing the curvature of the oligomer backbone leads to the adjustment of the interior cavity size. Helices with interior cavities of 10 Å to >30 Å across, the largest thus far formed by the folding of unnatural foldamers, are generated. Cavities of these sizes are usually seen at the tertiary and quaternary structural levels of proteins. The ability to tune molecular dimensions …
Bulk And Interfacial Properties Of Quadrupolar Fluids, V.B. Warshavsky, Xiao Cheng Zeng
Bulk And Interfacial Properties Of Quadrupolar Fluids, V.B. Warshavsky, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
We extend Teixeira and Telo da Gama’s density-functional approach [J. Phys.: Condens. Matter 3, 111 (1991)] to study the vapor–liquid phase equilibria and planar interfacial properties of quadrupolar fluids. The density profile, surface ordering, surface polarization, and surface tension of quadrupolar fluids are evaluated. Particular attention is given to the temperature and quadrupole-strength dependence. It is found that the interfacial molecular ordering can arise entirely due to the quadrupole–quadrupole interaction. It is also found that the bulk-phase properties of the quadrupolar fluids satisfy the law of correspondence states. The reduced surface potential and surface tension can be well correlated by …
Heterogeneous Nucleation On Mesoscopic Wettable Particles: A Hybrid Thermodynamic/Density-Functional Theory, T.V. Bykov, Xiao Cheng Zeng
Heterogeneous Nucleation On Mesoscopic Wettable Particles: A Hybrid Thermodynamic/Density-Functional Theory, T.V. Bykov, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
A hybrid thermodynamic and density-functional theory for heterogeneous nucleation on mesoscopic wettable particles is developed. The nonlocal density-functional theory (DFT) is on basis of the weighted-density approximation (WDA) of Tarazona. The model system consists of a Lennard-Jones (LJ) fluid and a 9–3 LJ wall for the solid particle. Effects of the droplet curvature and compressibility are accounted for in the theory. A by-product of this work is the calculation of the Tolman length using the WDA-DFT (Appendix A). Important characteristics of the heterogeneous nucleation, including the chemical potential of the liquid condensate, the free energy of droplet formation, and the …
How Does Water Freeze Inside Carbon Nanotubes?, Kenichiro Koga, G.T. Gao, Hideki Tanaka, Xiao Cheng Zeng
How Does Water Freeze Inside Carbon Nanotubes?, Kenichiro Koga, G.T. Gao, Hideki Tanaka, Xiao Cheng Zeng
Xiao Cheng Zeng Publications
Phase behavior of quasi-one-dimensional water confined inside a carbon nanotube is studied in the thermodynamic space of temperature, pressure, and diameter of the cylindrical container. Four kinds of solid-like ordered structures—ice nanotubes—form spontaneously from liquid-like disordered phases at low temperatures. In the model system that comprises of TIP4P water molecules interacting with each other via short-range Lennard–Jones and long-range Coulomb site–site potentials under a periodic boundary condition in the axial direction, the phase change occurs either discontinuously or continuously depending on the path in the thermodynamic space. That the isotherms for a given diameter are found to be similar to …