Division of Materials Research

Simulation of heat and fluid flow of crystal growth

We are working on computational fluid dynamics(CFD) to analyze fluid phenomena by computer simulation. In particular, we focus on the CFD of multiphase flow in which gas, liquid, and solid phases coexist and flow while interacting with each other. Multiphase flow is intimately related to crystal growth.　　In addition to the simulation method used to analyze the convection, diffusion, and mixing of several kinds of liquid at an interface, we carry out simulation of the interaction between liquid and solid particles and among liquids, bubbles, and particles. We are also involved in experimental research on the development of a method of controlling the movement of disperse phases such as particles and bubbles using vortices in a liquid.

Preparation of porous monoliths by the phase separation method and their applications to HPLC columns
and battery electrodes.

Based on the liquid-phase synthesis utilizing polymerization-induced phase separation, we are developing various porous materials ranging from ceramics, organic polymers to organic-inorganic hybrids. The materials with a controlled porous structure are applied to separation media, adsorbents, catalyst supports and battery electrodes. We aim at revealing the influence of pore property on each functionality by interdisciplinary researches with analytical chemistry, organosynthesis and electrochemistry in order to contribute to the development in energy and environmental fields.

Development and Their Applications of Hard & Flexible Materials.

In general, flexible materials bearing high recoverability from a large deformation are soft, while hard materials with high elastic modulus show poor flexibility.  We aim at developing novel porous materials with both high flexibility and high stiffness by designing macromolecular structures as well as porous morphologies.

Functional properties of various ceramic materials are often related to the atomic structures and electronic states in the lattice mismatch regions such as the surfaces, grain boundaries, and interfaces. We are attempting to develop new functional ceramic materials including new ceramic processing techniques from the viewpoint of controlling the lattice mismatch region using the nanoscale analysis technique of high-resolution transmission electron microscopy.

My group is involved in the development of machine learning algorithms for chemical data, the automatic design of molecules using structure‒property relationships, study on excited state dynamics, parallel algorithms and programs for material simulations on massively parallel computers, and new quantum-chemical theory for molecules and solids （ neural networks, graph theory, graphics processing units, CUDA, density matrices, Green’s function）.

Ab initio study of the photoabsorption and charge separation process on the dye-sensitized semiconductor surface. A neural net learns the predicted structure-property relations and suggests better dyes.

Our goal is to pursue the energy conversion via spin currents and to contribute to the construction of an energy-creating and energy-saving society in the future. In particular, we are working on experimental and theoretical studies of spin caloritronics, which explores the physics of the interaction between heat and spin, and on the development of materials and devices for generating spin currents from heat currents to generate electric power. Moreover, we are conducting research and development on the creation of new functional magnetic materials that will contribute to next-generation magnetic recording materials, permanent magnet materials, and spintronic devices.

Research concept of the Engineering for Nano-spintronics and Magnetic Materials Group

Defect species are recognized as a source of functionalities in energy materials such as catalysts and battery materials. However, the material development based on defect engineering is not yet established so far due to its difficulties. We aim to explore innovative energy functional materials by rational design and precise manipulation of defect structures.

  Nanomaterials with controlled size, morphology, and dimensions have been emerging as important new materials owing to their unique properties. In particular, two-dimensional（2D） nanosheets, which possess atomic or molecular thickness, have opened up new possibilities in exploring fascinating properties and novel devices. The Materials Processing Section is working on the creation of inorganic 2D nanosheets and the exploration of their novel functionalities in electronic and energy applications.

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  Controlled assembly of 2D nanosheets and its application to electronic devices.

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Nanoparticles and other nanosized materials (nanomaterials) not only have novel physical properties that differ from those of bulk materials, but also exhibit even more novel properties when they are arranged in an orderly manner to form higher-order structures. To successfully bring out these properties, precise structuring technology of nanomaterials is necessary, but it is not easy to control the higher-order structure of nanomaterials alone.

In the Self-Assembled Functional Nanomaterials Division, we are studying crystallization of nanomaterials by controlling the interaction between nanomaterials and precisely controlling their arrangement and higher-order structures, utilizing the self-assembling ability of biomolecules such as nucleic acids. By creating novel materials that exhibit physical phenomena at the nanoscale, we contribute to the development of devices based on completely new principles.