Engineering for Nanoscale Confined Space ーActive Use of Interface for Structure Control-

 For the present-day chemical engineering, which changes its purpose from "composition control" to "structure/function control", firstly needed would be an equation, [interacting elements] x [external field] = [controlled structure]: The interacting elements such as molecules, ions and nanoparticles often exhibit peculiar behavior when placed within external potential fields of, e.g., nanospaces and solid substrates. Their structure evolution and/or phase transitions should thus be observed carefully, understood physically, and modeled quantitatively for active use of external fields originating from interfaces for controlling the structures.
 Concerning nano- and submicron-scale, which enhances the interfacial effect, the researchers in this laboratory devote their efforts to the following research subjects, aiming at systematic under-standing and contribution to chemical engineering fundamentals, which would stand for potential applications to production of functional materials and various devices utilizing interfaces.

  • Simulation and Modeling of Phase Behavior in Nanospace, and Nanopore Characterization

    Recent advance in nano-spaced materials has been producing fascinating porous media such as MCM-41 and controlled nanoporous carbons. For appropriate and extensive applications of these new media, the understanding of phase behavior of confined fluids in nanopores is quite important. Exploration by molecular simulation is conducted not only for phase transitions in single-component systems, but also for binary systems. Thus obtained microscopic understandings are to be sublimated as engineering models to predict the phase behavior, and to be used for nanopore characterization.

  • Mechanism of Structural Transition of Compliant Crystals

    As typically seen in metal-organic frameworks, compliant crystals exhibit stepwise uptake of guest molecules upon its lattice transition, which has potential application in separation and storage. Extensive molecular simulations together with free-energy analysis yield valuable insights into the complicated phenomenon, which will provide possible strategy for designing and applying these materials.

  • Spontaneous Structure Evolution by Nano-Particles under External Field

    Ordered structures made up by 100 nm or smaller particles, or nanoparticles in the broad sense, can exhibit unique functions. The relation between operating condition and evolved structure is investigated experimentally, with the aid of the analysis by Brownian dynamics technique, which should be, in general, applied more for engineering purposes to fill the gap between microscopic analysis and macroscopic operating conditions.

  • Production of Functional Particles by Micro- and Nano-Reactors

    The key issue for efficient production of functional particles would firstly be the control of their nucleation processes, which must determine subsequently formed higher-order structure. Extensive mixing in micro-channels and confinement in nano-reactors such as dendrimers will give basic insight for optimal external field for targeted materials.