Summary

Nano-sized highly functional materials, which take the form of nanoparticles, nanowires, and nanosheets, are attracting attention, but in order to take full advantage of their capabilities, the establishment of highly-controlled alignment techniques is essential. However, essential in the aim to establish this technology is wide-ranging collaboration that includes production of uniformly-sized nanostructures, establishment of sophisticated purification technology for these nanostructures, alignment control using self-assembly technology, and establishment of fixation technology for the electrodes, etc. that are essential for making nanostructure devices. This research group has the technology required in each of these areas and close collaboration is possible. Therefore, research groups centered on the above-mentioned members will be established, and advanced alignment control of nanostructures will be conducted with this series of collaborative technologies as the key topics.

Supervisors (Representative*) :

Eiji Kanezaki*, Yasuhiro Uosaki, Toshio Takayanagi, Mikito Yasuzawa, Yoshihisa Suzuki, Tomoki Yabutani, Masashi Kurashina, Ken Yoshida

Research topics

1. Structure, Reaction, and Dynamics in Supercritical Fluids
   1-1　Outline

   Supercritical fluids have nano-scale fluid structures due to the large density fluctuations. Thus the chemical reactions in supercritical fluid can be regarded as the “nano-scale interfacial reactions”. There are wide varieties of possible applications of the supercritical fluid reactions, such as particle-size reduction, production of value-added species and sustainable energies from biomass, etc. Toward the practical use of the supercritical fluids, it is of great importance to establish the fluid properties as pure solvents, phase behaviors of supercritical-fluid solutions as multi-component systems, solubility of solutes in supercritical fluids, and the reaction schemes and kinetics in extreme high-pressure conditions. The purpose of this study is to develop a novel chemical processes on the basis of the physical chemistry by using mainly carbon dioxide and water in supercritical states.

    

   1-2　Keywords

   Supercritical fluids, environmentally-friendly reactions, nano-scale interface

    

   1-3　Supervisors

   Yasuhiro Uosaki*, Ken Yoshida

    

2. Production of Large 3D Photonic Crystals with Full 3D Band Gaps
   2-1　Outline

   A structure whose refractive index is periodically modulated on a scale of the wavelength of light is called a photonic crystal. Three-dimensionally large perfect crystals with full 3D band gaps are essential in order to realize ideal optical circuit. This research aims to produce large 3D photonic crystals with full 3D band gaps through crystallization control that combines an optical trapping method and a centrifugal sedimentation method, etc. In addition, chemical modification processes of protein crystals (glucose isomerase, lysozyme, ferritin etc.) for their optical and chemical application are developed. Ferritin is known as a globular protein, and it is valued as a surface modification material that uses this hollow-globular structure. Although techniques for aligning ferritin (two-dimensionally) on the surface of solids are occasionally found, synthesis methods for large three-dimensional structures are very limited. Large-scale and three-dimensional ferritin crystals provide us with wide chemical/material applications, as a result of exhibiting precise size exclusion properties due to micropores with high specific surface area and very uniform size-distribution, etc. There is an urgent need for development of an advanced alignment control method for this purpose. This research examines synthesis of three-dimensional, ordered structures of ferritin using gravitational sedimentation/drying/salting-out methods, templating of this ordered structure (inverse opal structure), and its application to separation/analysis devices.

    

   2-2　Keywords

   Colloidal crystal, submicron particle, optical tweezer effect, centrifugal sedimentation method, inverse opal, lysozyme, Ferritin, ordered structure, alignment control, separation, analytical chemistry

    

   2-3　Supervisors

   Yoshihisa Suzuki*, Tomoki Yabutani*, Eiji Kanezaki, Masashi Kurashina

    

3. Production of Blood Glucose Level Sensor to Ease Burden on Diabetic Patients
   3-1　Outline

   Diabetic patients require detailed monitoring of their blood glucose levels, but traditional blood sampling methods place an excessive burden on patients both physically and mentally. This research aims to produce a very thin, blood glucose level sensor with a diameter of 0.3 mm or below. As well as being thin, the sensor will be able to withstand practical use, being unbreakable when embedded and being usable for several months with no drop in enzyme activity. The possibility of practical application of the produced sensor will be explored using methods such as biometric measurement by embedding the sensor in rats.

    

   3-2　Keywords

   Diabetes, blood glucose level, enzyme activity, biometric measurement

    

   3-3　Supervisors

   Mikito Yasuzawa*, Toshio Takayanagi, Tomoki Yabutani

    

4. Construction of Functional Substances through Preparation of Nanosheets of Metal Layered Hydroxide and Restacking
   4-1　Outline

   Metal hydroxides include layered compounds in which two-dimensional sheet structures are layered on top of each other. By separating these sheets one at a time to create nanosheets at a molecular level and restacking nanosheets obtained from various layered compounds, this research aims to produce a structure in which the order of the layers is freely modified. New electrical/magnetic functions can be expected depending on the combination of nanosheets forming the raw material and their order.

    

   4-2　Keywords

   Nanosheet, layered compound, metal hydroxide, restacking

    

   4-3　Supervisors

   Eiji Kanezaki*, Yoshihisa Suzuki, Tomoki Yabutani, Masashi Kurashina

    

5. Development of Analytical and Separation Methods with Nano-sized Molecular Assembly
   5-1　Outline

   Nano-sized molecular assemblies of surfactant micelles, vesicles, microemulsions, and polymer gels possess hydrophobic environment. Specific surface area of the molecular assemblies is greatly larger than that of bulk water-organic solvent interface. Extraction-separation with the characteristic hydrophobic environment of the molecular assemblies works in pseudo-homogeneous aqueous solution. Liquid-liquid extraction is done in the pseudo-homogeneous aqueous solution without mechanical shaking of the two phases, with fast extraction kinetics, as well as with the selectivity towards ionic substances. Functional Molecular Assembly including micelles, microemulsions, and hydrophobic matrices are to be developed.

    

   5-2　Keywords

   Surfactant micelle, microemulsion, hydrophobic partition, aquatic solvent, analytical separation

    

   5-3　Supervisors

   Toshio Takayanagi*, Yasuhiro Uosaki, Tomoki Yabutani, Mikito Yasuzawa, Ken Yoshida