Supercritical Hydrothermal Synthesis of Organic-Inorganic Hybrid Nanoparticles

Features

We invented supercritical hydrothermal synthesis method for the synthesis of organic modified nanoparticles (NPs). Under the supercritical state, the organic molecules and metal salt aqueous solutions are miscible and water molecule works as an acid/base catalyst for the reactions. Organic-inorganic conjugate NPs can be synthesized under this condition. This hybrid NPs show high affinity with the organic solvent or the polymer matrix, which leads to fabricate the organic inorganic hybrid nanomaterials with the trade-off function (super hybird nanomaterials). These hybrid materials of polymer and ceramics fabricated with NPs achieve both high thermal conductivity and easy thin film flexible fabrication, namely trade-off function.

Targeted Application(s)/Industry

For example, by the surface modification of BN particles by supercritical method, affinity of BN and polymers could be improved, so that high BN content of hybrid materials, thus high thermal conductivity materials, could be synthesized. Also by dispersing high refractive index NPs like TiO2 or ZrO2 into polymers transparently, we can tune the refractive index of the polymers. CeO2 nanoparticles are expected to be used for high performance catalysts. To transfer those supercritical fluid nano technologies, a consortium was launched with more than 70 companies.

Novel CoCr-based superelastic metallic biomaterial with low Young's modulus

Features

General metallic biomaterials, such as stainless steels and conventional CoCr alloys, show a high Young's modulus ten times higher than that of human bones. This is an unfavored feature because it causes the so-called "stress shielding effect" when they are used as implants. β-type Ti alloys have a relatively lower Young's modulus, but they come with a compromise of low wear resistance. The current novel CoCr-based alloys are a breakthrough; they exhibit both a low Young's modulus similar to human bones and a high wear and corrosion resistance. Moreover, they exhibit superelasticity with a huge recoverable strain over 17%, also showing promise as shape memory alloys.

Targeted Application(s)/Industry

It is the first time that a low Young's modulus, a high corrosion and wear resistance, and a superior superelastic behavior are simultaneously obtained in a single material. The current novel CoCr-based alloys are promising for biomedical applications such as total hip or knee joint replacements, bone plates, spinal fixation devices, and vascular stents.

Novel Cu-Based Shape Memory Alloy with High Ductility

Features

Recently, we have developed a novel Cu-Al-Mn based shape memory alloy with high SM properties and with a ductility twice higher than that in Nitinol . Furthermore, this novel SM alloy needs no die for the shape setting and is fabricated with relatively low cost. Very recently, we have successfully developed a device to cure ingrown toenail by using this SM alloy.

Targeted Application(s)/Industry

Very recently, we established a fabrication process for the Cu-Al-Mn sheet, wire and bar with 0.1 - 20mm in thickness or diameter. We hope to conduct collaborative research with a willing company for a practical application with this new SM alloy.

Development of Vector Beam and its Application to Nanoimaging

Features

Vector beams are very attractive because of their unique features such as small spot formation and strong longitudinal electric field near focus. We are developing a variety of generation methods of vector beams including Laguerre-Gaussian and Bessel-Gaussian beams and their higher order transverse modes. For instance, a smaller spot by approximately 30 % than that by a linearly polarized beam has been demonstrated and applied for nanoimaging.

Targeted Application(s)/Industry

Confocal scanning microscpy will benefit from vector beams as enhancement of spatial resolution. Otherwise, precision nano-processing will be possible. We are prepared to provide academic consultations to companies interested in our research.

Molecular Dynamics Analysis of Coating and Surface Modification

Features

Molecular-scale mechanism of solid-liquid affinity, wettability, thermal boundary resistance and molecular deposition are analyzed by molecular dynamics simulations toward its control. With a background of heat and mass transport and interfacial thermodynamics, transport phenomena of various scales ranging from spin coating of photoresist to SAM (self-assembled monolayer) and hydrophobic/hydrophilic treatment by attaching some molecular basis are studied. Futhermore, the molecular-scale mechanisms which determine thermophysical properties and the molecular structure that realizes desired thermophysical properties are studied. We can conduct effective collaboration and provide academic consultations to companies interested in our research.

Development of Nano-Interface Chemistry for Materials Sciences Using Surface Forces Measurement

Features

Our research aims at developing methods, including instrumentation, for characterizing surface (or interface) at the nano-meter level. Most of our research subjects are related to the surface forces measurement, which can directly monitor the interaction between two surfaces. We study phenomena occurring at the solid-liquid interface such as adsorption and structuring of liquids. We have developed the resonance shear measurement which is a sensitive method for evaluating properties of confined liquid for nano-rheology and tribology. Twin-path surface forces apparatus we developed enabled us to study wide variety of samples such as metals, ceramics and plastics.

Targeted Application(s)/Industry

These methods are applicable for characterizing lubricants, nano-materials, paints, sealants, and cosmetics. We hope to conduct collaborative research with a willing company for a practical application of this technology in industry.

Advanced Control of Microstructure and Property of Structural Metallic Materials

Features

Microstructure represents various kinds of heterogeneities in the metallic materials, i.e., grains, component phase, lattice defects and chemical inhomogeneity such as impurity/alloying elements. It can be modified through control of phase transformation/precipitation and deformation/recrystallization by adjusting compositions of materials and/or through processing routes (heat treatment, deformation). Such expertise in micro/nanostructure control is very important in production of current materials from viewpoints of energy saving and recycling in structural materials such as steels and titanium alloys.
We attempt to apply more advanced control of micro/nanostructures, such as atomic structures of crystalline interfaces, chemistory in an atomic scale (e.g., segregation) and so on. Fundamentals of microstructure formation (thermodynamics, kinetics, crystallography) are examined both theoretically and experimentally to clarify key factors for microstructure control. Another important aspect in our research is the improvement of mechanical property by microstructure manipulation.

Targeted Application(s)/Industry

Possibilities to establish new functions (e.g., superplasticity, shape memory/superelasticity) as well as superior mechanical properties (e.g., ultrahigh strength with high toughness/ductility) is also explored.