KANEKO Laboratory
<Major Research Areas>Eco-materials, Natural molecules, Liquid crystals, Nano-composites, Optical materials

Designing Material for Global Preservation by
Controlling π-electrons

Research activity

　　The greatest challenge for researchers living in the 21st century is to solve the global environmental problems that are getting worse along with the development of science. The solutions of these problems will enable not only sustainable development of human beings, but also coexistence with other fauna and flora. Based on this standpoint, our laboratory aims to develop environment-friendly material using cutting-edge science. In particular, we focus on aromatic molecules that have a lot of high-performance π-electrons. Since these molecules are sometimes extremely poisonous to the environment, we are developing a technology that will change them into an environment-friendly material by controlling the structure of the π- electron molecule hierarchically on the nano- and macro-scales.

1Development of π-electron Phytomonomer

　　Useful π-electron material is produced from biological resources such as plants and microorganisms, and is compounded into polymers by chemical polymerization. Such phytomonomers of plant origin are used for producing liquid crystal material, organic conductive material, optical memory media, etc. We regard “phyto”-monomers as an organic source material that can “fight” global environmental problems.

2Nano-scale Designing of Polymer Chains

　　Phytomonomers contain abundant polyfunctional molecules with complex structures, which cannot be synthesized by means of petrochemical technology. Paul J. Flory, a Nobel Prize-winning US polymer chemist, theoretically proved that hyperbranched polymers can be compounded from polyfunctional molecules by chemical polymerization. A “hyperbranched polymer” has a molecular chain structure with many branches, which is extremely sensitive to environmental changes (like leaves on trees), and provides new functions for materials. The use of hyperbranching is a powerful innovation for the construction of environment-friendly molecule structures. We develop high-performance green materials by means of nano-scale design and organization of polymer chain structures.

3Production of High-performance Environmentally-degradable Polymers

　　We have succeeded in the production of liquid crystalline highperformance plastic, one of the hyperbranched polymers, which can change molecular structure due to ultraviolet light irradiation, and become biodegradable. This plastic can be used for disposal of home electronic appliances and automobile parts, by projecting artificial ultraviolet light with a specific wavelength onto them, to induce a molecular change that creates biodegradable plant molecules. This is a breakthrough concept for producing the ultimate environment-friendly material.

Equipment

Rheometer for solid and liquid materials, fluorescence polarization microscope, mechanics testing instrument for microscopic observation, vertical and revolving stirring unit, image analysis application software, diamond ATR device, ultrasonic soldering device for transparent electrodes, bipolar power supply, and function generator

The main research achievements in the past five years

1. M. Okajima, T. Higashi, R. Asakawa, T. Mitsumata, D. Kaneko, T. Kaneko, T. Ogawa, H. Kurata, S. Isoda, Gelation behavior by the lanthanoid adsorption of the cyanobacterial extracellular polysaccharide, Biomacromolecules, 11 (11), 3172-3177 (2010)
2. M. Okajima, M. Nakamura, T. Mitsumata, T. Kaneko, Cyanobacterial Polysaccharide Gels with Efficient Rare-Earth-Metal Sorption, Biomacromolecules, 11(7), 1773-1778 (2010)
3. M. Okajima, D. Kaneko, T. Mitsumata, T. Kaneko, and J. Watanabe, Cyanobacteria that produce megamolecules with efficient self-orientations, Macromolecules, 42, 2881-3218 (2009) (cover).
4. M. Okajima, T. Bamba, Y. Kaneso, K. Hirata, S. Kajiyama, E. Fukusaki, and T. Kaneko, Supergiant ampholytic sugar chains with imbalanced charge ratio form saline ultra-absorbent hydrogels, Macromolecules, 41, 4061-4064 (2008).
5. T. Kaneko, H. T. Tran, D. J. Shi, and M. Akashi, Environmentally-degradable, high-performance plastics from phenolic phytomonomers, Nature Mater., 5, 996-970 (2006).