Isamu Kusaka Group for Molecular Thermodynamics
Isamu Kusaka Group for Molecular Thermodynamics
Statistical mechanics and transport phenomena in nano scale systems
About
Education
 Ph.D., CalTech, 1998
 M.S., University of Tokushima, 1990

B.S., University of Tokushima, 1988
Professor Kusaka's research expertise is in statistical mechanics and transport phenomena in nanoscale systems. His current research effort is aimed at developing efficient algorithms for simulating nucleation of complex molecules. More phenomenological and less computationally demanding approaches are also developed. Ongoing research projects include a theoretical account of micelleassisted cavitation, computer simulation of crystallization of molecular fluids, and a development of a force field to describe aromatic hydrocarbonwater clusters.
Expertise
 Thermodynamics and statistical mechanics of nucleation.
 Statistical mechanics of transport phenomena.
 Particle based simulation methods (Monte Carlo, molecular dynamics, and dissipative particle dynamics).
 Statistical mechanical density functional theory.
Selected Achievements

Kusaka generalized the LoweAndersen thermostat originally meant for isothermal dissipative particle dynamics simulation. At equilibrium, the resulting thermostat generates a microcanocnical instead of canonical ensemble while conserving the total linear momentum, and allows for a nonuniform temperature field at a steadystate.

Kusaka developed a mathematical expression for the replacement partition function corresponding to a part of the translational and rotational free energy of a critical nucleus that is already accounted for in the classical expression for the free energy of critical nucleus formation. This made it possible to evaluate the LothePound factor by means of a molecular simulation.
KEY DISTINCTIONS
Professor Kusaka is the author of a book on Statistical Mechanics, numerous publications, and software.
Visit Orcid and the links below for more information.
For more news about Professor Kusaka and his research group, please visit our chemical engineering department's website.
Research
A satisfactory account of transport phenomena at a molecular level is an outstanding problem of nonequilibrium statistical mechanics with important practical implications on a wide range of engineering applications, including gas and liquid separation in porous membrane, heterogeneous catalysis, nanofluidcs, and enhanced oil and gas recovery.
A common thread in these systems is the strong inhomogeneity of the fluid phases over a nano meter level length scale, making a direct molecular dynamics simulation an appealing theoretical tool of choice. However, the length and time scales accessible to typical molecular dynamics are still very limited.
Statistical mechanical density functional theory (DFT) holds an exciting promise to fill this gap. Since its inception, DFT has been applied successfully to probe phase behavior and microscopic structures of fluids in equilibrium from a molecular level perspective while requiring a fraction of a typical computational cost of molecular level simulations. DFT provides a much easier access to an activated state (in unstable equilibrium) involved in a rare event such as nucleation. It can also offer deep insights that are otherwise unavailable into physics of inhomogeneous systems.
Currently, we are developing dynamical extension of DFT so that transport phenomena can be explored from a molecular level perspective with DFT.
When a body liquid water is heated under one atmospheric pressure, it starts to boil at 100C°. If we continue to add heat to the body, the entire water will eventually be converted into a vapor phase. If this vapor phase is cooled at the same pressure, it will start to condense, again, at 100C°. When the same process is repeated at a lower pressure, say at 0.1atm, the liquid phase will boil at 46C° and the vapor phase will condense at this temperature. The locus of the boiling temperature at various pressure then defines the boundary that separates the two phases. Essentially the same consideration applies to transition between solid and liquid phases, and that between solid and vapor phases.
This simplistic view, however, is not entirely accurate. For example, when impurities, such as dust particles, are carefully removed, pure vapor water can be compressed by several times of its density at saturation before it starts to condense. A cup of liquid water can be superheated in a microwave oven. The possible subsequent sudden boiling is a dangerous reminder of the reverse process.
Nucleation is an initial stage of the socalled first order phase transition, in which an embryo of a new and more stable phase forms in a metastable matrix phase. Its subsequent growth and coalescence with other similarly formed embryos lead to the eventual emergence of an macroscopic amount of the new phase. Nucleation plays a crucial role in various context ranging from global climate modeling to manufacturing processes, chemical/pharmaceutical industry and biological processes.
Experimental results of nucleation are correlated almost exclusively in terms of the so called classical nucleation theory, which relies on macroscopic thermodynamic quantities such as the bulk chemical potentials and the surface tension. Despite its predominant use in practice, classical theory suffers from many shortcomings. Its predictions of nucleation rate are usually in error by many orders of magnitude. The theory does not offer any information on the molecular level structure of the embryos involved in nucleation.
In contrast to assumptions in classical theory, distribution of molecules in multicomponent droplets may not be uniform, greatly affecting their reactivity in the atmosphere. Manufacturing of plastic foam takes advantage of bubble nucleation in liquid polymer supersaturated with gas phase species. Accurate knowledge of the rate of nucleation is important in controlling the physical properties of the foams. In crystal nucleation, polymorphism, defined as the ability of a material to crystallize in different structures, is an important issue as the functionality of the crystal, such as the optoelectrnic properties and the bioavailability of a drug, can depend strongly on the crystal structure.
In order to address the shortcomings of classical theory and to gain mechanistic insights into the nucleation process, we employ various machineries of statistical mechanics, including computer simulation and statistical mechanical density functional theory.
Group Members
GRADUATE STUDENTS
Current:
 Nicholas T. Liesen
 Wenhan Jia
Former:
 Pankaj A. Apte (Now an Assistant professor at the Indian Institute of TechnologyKanpur)
 Manish Talreja (Dow Chemical)
 Adam C. Burley (Continental Structural Plastics)
UNDERGRADUATES
 Daniel J. Griffin (Now at a graduate program at the Georgia Institute of Technology)
 Nicholas Liesen (Graduate program at the Ohio State University.)
Publications
Among the large number of textbooks on statistical mechanics that exist today, few are accessible without a substantial background in physics. This book is intended to server as a gentle introduction to statistical mechanics for engineers who approach this subject for the first time without the necessary training in physics.
For details, visit publisher's web page here.
eBook version of the book can be found here. Alternatively, access the content (pdf files) through the OSU library at this link.
Table of Contents
Main Text
 Classical Mechanics
Newton's equations of motion, Lagrangian, Hamiltonian.
 Thermodynamics
A brief review of thermodynamics.
 Classical Statistical Mechanics
Canonical ensemble and its applications.
 Various Statistical Ensembles
Microcanonical, canonical, grand canonical, isothermalisobaric ensembles, and their applications.
 Simple Models of Adsorption
Lattice gas, phase transition.
 Thermodynamics of Interface
An introduction to thermodynamics of interfaces following Gibbs.
 Statistical Mechanics of Inhomogeneous Fluids
An introduction to statistical mechanical density functional theory.
 Quantum Formulation
Dirac's bracket notation and its use in formulating statistical mechanics.
Appendices
 Vectors in 3Dimensional Space
 Useful Formulae
 Legendre Transformation
 Dirac δFunction
 Where to Go from Here
 List of Greek Letters
 Hints to Selected Exercises
2021
 Jia, Wenhan; Kusaka, Isamu, "Density functional study of nonisothermal hard sphere fluids." MOLECULAR PHYSICS. DOI:10.1080/00268976.2021.1875077
 Kusaka, Isamu; Jia, Wenhan, "Equilibrium properties of penetrable soft spheres." MOLECULAR PHYSICS 119, e1802076, DOI: 10.1080/00268976.2020.1802076
2020
 Liesen, Nicholas T; Palermo; Gabriel A; Kusaka, Isamu; Egusa Shunji, "Measurement and prediction of kinematic viscosity for linear ethers." JOURLAN OF CHEMICAL PHYSICS 153, 024502, DOI:10.1063/5.0007591
 Kusaka, Isamu; Liesen, Nicholas T, "Integrating dissipative particle dynamics with energy conservation." PHYSICAL REVIEW E 101, 042120, DOI:10.1103/PhysRevE.101.042120
2015
 Kusaka,Isamu, Statistical Mechanics for Engineers," Springer.
2014
 Xu,Xiaofei; Ting,Christina,L; Kusaka,Isamu; Wang,ZhenGang, "Nucleation in Polymers and Soft Matter." Annual Review of Physical Chemistry 65 449475
2013
 Kusaka,Isamu; Talreja,Manish; Tomasko,David, L, "Beyond Classical Theory: Predicting the Free Energy Barrier of Bubble Nucleation in Polymer Foaming." AIChE JOURNAL 59 8 30433053
2012
 Guo,Zhihua; Burley,Adam,C; Koelling,Kurt,W; Kusaka,Isamu; Lee,L,James; Tomasko,David,L, "CO2 bubble nucleation in polystyrene: Experimental and modeling studies." JOURNAL OF APPLIED POLYMER SCIENCE 125 3 21702186
 Talreja,Manish; Kusaka,Isamu; Tomasko,David,L, "Analyzing surface tension in higher alkanes and their CO2 mixtures." FLUID PHASE EQUILIBRIA 319 6776
2010
 Kusaka,Isamu, "学問を通じての出会い (Reflection on my encounters in science, in Japanese)." 高分子 (Polymer) 59 215216
2009
 Tomasko,David,L; Burley,Adam; Feng,Lu; Yeh,ShuKai; Miyazono,Koki; NirmalKumar,Sharath; Kusaka,Isamu; Koelling,Kurt, "Development of CO2 for polymer foam applications." JOURNAL OF SUPERCRITICAL FLUIDS47 3 493499
 Talreja,Manish; Kusaka,Isamu; Tomasko,David,L, "Density functional approach for modeling CO2 pressurized polymer thin films in equilibrium." JOURNAL OF CHEMICAL PHYSICS 130 084902
 Kusaka,Isamu, "Accelerating simulation of metastable decay." JOURNAL OF CHEMICAL PHYSICS 131 034112
2008

Kusaka,Isamu, "核生成の統計力学 (Statistical mechanics of nucleation, in Japanese)." アンサンブル (Ensemble) 10 3435
2006
 Apte,P,A; Kusaka,I, "Evaluation of the translational free energy in a melting temperature calculation by simulation." PHYSICAL REVIEW E 73 016704
 Kusaka,I, "Statistical mechanics of nucleation: Incorporating translational and rotational free energy into thermodynamics of a microdroplet." PHYSICAL REVIEW E 73 031607
 Apte,Pankaj,A; Kusaka,Isamu, "Direct calculation of solidvapor coexistence points by thermodynamic integration: Application to single component and binary systems." JOURNAL OF CHEMICAL PHYSICS 124 184106
2005
 Apte,P,A; Kusaka,I, "Direct calculation of solidliquid coexistence points of a binary mixture by thermodynamic integration." JOURNAL OF CHEMICAL PHYSICS 123 194503
2004
 Apte,P,A; Kusaka,I, "Bubble nucleation in micellar solution: A density functional study." JOURNAL OF CHEMICAL PHYSICS 121 24 1253212542
2003
 Kusaka,I, "On the scaling behavior of the free energetics of nucleation." JOURNAL OF CHEMICAL PHYSICS118 12 55105515
 Kusaka,I, "System size dependence of the free energy surface in cluster simulation of nucleation." JOURNAL OF CHEMICAL PHYSICS 119 7 38203825
 Kusaka,I, "A scaling function of nucleation barrier based on the diffuse interface theory." JOURNAL OF CHEMICAL PHYSICS 119 3 18081812
2001
 Kusaka,I; Oxtoby,D,W, "A Monte Carlo simulation of nucleation in amphiphilic solution." JOURNAL OF CHEMICAL PHYSICS 115 10 48834889
 Kusaka,I; Oxtoby,D,W; Wang,Z,G, "On the direct evaluation of the equilibrium distribution of clusters by simulation. II." JOURNAL OF CHEMICAL PHYSICS 115 15 68986906
2000
 Kusaka,I; Oxtoby,D,W, "A Monte Carlo simulation approach to nucleation in microemulsions." NUCLEATION AND ATMOSPHERIC AEROSOLS 2000 534 402405
 Kusaka,I; Oxtoby,D,W, "Evaluating free energy, enthalpy, and entropy of protonated water clusters by a grand canonical Monte Carlo simulation." JOURNAL OF CHEMICAL PHYSICS 113 22 1010010104
1999
 Kusaka,I; Oxtoby,D,W, "Identifying physical clusters in bubble nucleation." JOURNAL OF CHEMICAL PHYSICS111 3 11041108
 Kusaka,I; Oxtoby,D,W, "Identifying physical clusters in vapor phase nucleation." JOURNAL OF CHEMICAL PHYSICS 110 11 52495261
 Kusaka,I; Oxtoby,D,W; Wang,Z,G, "On the direct evaluation of the equilibrium distribution of clusters by simulation." JOURNAL OF CHEMICAL PHYSICS 111 22 99589964
1998
 Kusaka,I; Wang,Z,G; Seinfeld,J,H, "Binary nucleation of sulfuric acidwater: Monte Carlo simulation." JOURNAL OF CHEMICAL PHYSICS 108 16 68296848
 Kusaka,I; Wang,Z,G; Seinfeld,J,H, "Direct evaluation of the equilibrium distribution of physical clusters by a grand canonical Monte Carlo simulation." JOURNAL OF CHEMICAL PHYSICS 108 9 34163423
1996
 Kusaka,I; Wang,Z,G; Seinfeld,J,H, "Monte Carlo simulation of homogeneous binary nucleation: Toward a theory of sulfuric acidwater system.." NUCLEATION AND ATMOSPHERIC AEROSOLS 1996 3437
1995
 Kusaka,I; Wang,Z,G; Seinfeld,J,H, "IONINDUCED NUCLEATION  A DENSITYFUNCTIONAL APPROACH."JOURNAL OF CHEMICAL PHYSICS 102 2 913924
 Kusaka,I; Wang,Z,G; Seinfeld,J,H, "IONINDUCED NUCLEATION .2. POLARIZABLE MULTIPOLAR MOLECULES." JOURNAL OF CHEMICAL PHYSICS 103 20 89939009
1992
 Nishioka,K; Kusaka,I, "THERMODYNAMIC FORMULAS OF LIQUIDPHASE NUCLEATION FROM VAPOR IN MULTICOMPONENT SYSTEMS." JOURNAL OF CHEMICAL PHYSICS 96 7 53705376
1991
 Tomino,H; Kusaka,I; Nishioka,K; Takai,T, "INTERFACIALTENSION FOR SMALL NUCLEI IN BINARY NUCLEATION." JOURNAL OF CRYSTAL GROWTH 113 34 633636
1989
 Nishioka,K; Tomino,H; Kusaka,I; Takai,T, "CURVATURE DEPENDENCE OF THE INTERFACIALTENSION IN BINARY NUCLEATION." PHYSICAL REVIEW A 39 2 772782
Polymer density functional theory package for bulk and interfacial properties
Usage of the code is explained in appendices A and B of Dr. Manish Talreja's thesis.