Takeo Ozawa was a Japanese materials scientist whose career advanced thermal analysis, non-isothermal kinetics, electrical insulating materials, polymers, and energy storage. His 1965 method for analyzing thermogravimetric data became widely known as the Ozawa method or Ozawa plot, while his later work connected thermal measurement with industrial materials research and international scientific societies.
Background
Takeo Ozawa was born on February 14, 1932, in Yokohama, Kanagawa, Japan, to Soyozo and Hide Ozawa, née Okano. Yokohama was a major international port and industrial city, and its cosmopolitan setting formed the geographic background of his early life.
He married Hisae Tanaka on June 30, 1957. They had two children, Sayuri and Hidetoshi. His scientific career developed during Japan's postwar expansion of industrial research, when government laboratories and manufacturing companies were investing in electrical materials, polymers, electrochemistry, and energy technologies.
Education
Ozawa studied chemistry at the University of Tokyo, receiving a Bachelor of Science degree in 1955 and a Master of Science degree in 1957. The University of Tokyo, founded in 1877 as Japan's first national university, was the country's leading center for advanced scientific education and research during his student years.
He continued at the university while developing his research in thermal analysis and received a Doctor of Science degree in 1980. His doctoral thesis, Non-isothermal Kinetics and its Application to High Polymers, connected kinetic theory with the behavior of polymeric materials. The work reflected the growing importance of quantitative thermal methods in Japanese materials science and industrial chemistry.
Career
Ozawa began his professional career in 1957 at the Electrotechnical Laboratory in Tokyo, then part of Japan's Agency of Industrial Science and Technology within the Ministry of International Trade and Industry. The laboratory was a national center for research in electricity, electronics, measurement, and industrial materials. His early work concerned electrical and electronic insulating materials, whose thermal stability was important to the reliability of electrical equipment.
At the laboratory he applied thermogravimetry, differential thermal analysis, and related thermoanalytical techniques to materials research. His 1965 paper, A New Method of Analyzing Thermogravimetric Data, introduced a method for obtaining kinetic parameters from thermogravimetric curves recorded at different heating rates. The resulting relationship, widely called the Ozawa method or Ozawa plot, became an important approach to estimating activation energies in studies of polymers, ceramics, and other materials.
Ozawa became section chief at the Electrotechnical Laboratory in 1970 and worked there until 1987. His responsibilities and research interests included electronic chemistry, energy storage, thermal storage, polymeric materials, and the thermal behavior of superconducting oxides after the discovery of high-temperature oxide superconductors in 1986. He also participated in the development of a redox-flow battery and a latent thermal-storage system using high-density polyethylene.
In 1987 Ozawa joined Daicel Chemical Industries and became the first director of its newly established Tsukuba Research Center. Tsukuba Science City had developed as a concentration of national laboratories and research institutions, and the center provided an industrial setting for research on electronic and polymeric materials. He served as director from 1989 to 1992 and then as honorary director until 1997.
Ozawa became a professor in the Electrical Engineering Department of the Chiba Institute of Technology in 1997 and remained there until his retirement in 2003. Chiba Institute of Technology, founded in 1942, is a Japanese private university emphasizing engineering and applied science. He continued publishing on thermal analysis, calorimetry, polymeric insulating materials, energy technologies, and the history and methods of thermal measurement.
Achievements
Ozawa developed a kinetic method for analyzing thermogravimetric data recorded at different heating rates. The method, introduced in 1965, became widely known as the Ozawa method or Ozawa plot and has been applied to activation-energy estimation in thermal analysis of polymers, ceramics, and other materials.
Ozawa contributed to the development and application of thermal-analysis methods for electrical insulating materials, polymers, energy-storage systems, thermal storage, and oxide superconductors.
As the first director of Daicel Chemical Industries' Tsukuba Research Center, Ozawa helped establish the center's research activity in electronic and polymeric materials.
Ozawa held international leadership roles in thermal analysis and calorimetry, including the presidency of the International Confederation for Thermal Analysis and Calorimetry from 1992 to 1996.
(Ozawa proposed a method for obtaining kinetic parameters ...)
1965
Nonisothermal Crystallization of Poly(tetrafluoroethylene)
(This study applied thermal-analysis methods to the crysta...)
1984
Views
Ozawa's scientific work combined theoretical analysis with practical engineering. His research treated thermal-analysis methods not only as mathematical procedures but also as tools for understanding and improving materials, energy-storage systems, and industrial processes.
His published discussions of thermal analysis emphasized the need to relate measured curves to instrument behavior, heat transfer, temperature control, and the physical characteristics of samples. This approach connected fundamental kinetics with the design and evaluation of useful technologies.
Membership
Ozawa held leadership roles in professional organizations devoted to thermal analysis, calorimetry, thermophysical properties, chemistry, polymers, and electrical engineering. He was president of the Japan Society of Calorimetry and Thermal Analysis from 1993 to 1995, president of the Japan Society for Thermophysical Properties in 1995–1996, and president of the International Confederation for Thermal Analysis and Calorimetry from 1992 to 1996.
His international service also included committee work in standardization, nomenclature, education, and kinetics for thermal-analysis organizations. He served on the thermal engineering committee of the Science Council of Japan from 1986 to 1990 and contributed to the development of professional networks linking Japanese laboratories, industry, and international thermal-analysis research.
President, 1993–1995.
Japan Society of Calorimetry and Thermal Analysis
,
Japan
1969
President, 1992–1996; served on committees concerned with standardization, nomenclature, education, and kinetics.
International Confederation for Thermal Analysis and Calorimetry
,
International
1974
President, 1995–1996.
Japan Society for Thermophysical Properties
,
Japan
Member of the thermal engineering committee.
Science Council of Japan
,
Japan
1986 - 1990
Chemical Society of Japan
,
Japan
Society of Polymer Science, Japan
,
Japan
Institute of Electrical Engineers of Japan
,
Japan
Personality
Ozawa was described in a professional biographical account as someone who valued making things and developing new apparatus for thermal analysis and thermal-conductivity measurement. The same account noted his interest in Western and Japanese cooking, music, and reading.
Quotes from others about the person
Thermochimica Acta dedicated a special issue to Ozawa on the occasion of his sixty-fifth birthday and described his early papers as continuing to merit attention because of their relevance to contemporary thermal analysis.
Interests
Ozawa was interested in cooking, including both Western and Japanese cuisine, as well as music and reading.
Music & Bands
Music was among Ozawa's documented personal interests.
Connections
Ozawa married Hisae Tanaka on June 30, 1957. They had two children, Sayuri and Hidetoshi.
child:
Sayuri Ozawa
child:
Hidetoshi Ozawa
Wife:
Hisae Tanaka
Ozawa married Hisae Tanaka on June 30, 1957.
References
Takeo Ozawa and his Scientific Career
A biographical and scientific account of Ozawa's education, work at the Electrotechnical Laboratory, research on thermal analysis and energy storage, leadership in professional societies, and major awards.
Awarded by the North American Thermal Analysis Society in 1981 for contributions to thermal analysis.
Awarded by the North American Thermal Analysis Society in 1981 for contributions to thermal analysis.
Best Energy Storage Paper Award,
United States
Awarded by the American Society of Mechanical Engineers in 1986 for the co-authored paper Latent Thermal Storage Using Pentaerythritol Slurry, presented at the 21st Intersociety Energy Conversion Engineering Conference.
Awarded by the American Society of Mechanical Engineers in 1986 for the co-authored paper Latent Thermal Storage Using Pentaerythritol Slurry, presented at the 21st Intersociety Energy Conversion Engineering Conference.
Kurnakov Medal,
Russia
Awarded by the Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences in 1994 for contributions to thermal analysis and related materials research.
Awarded by the Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences in 1994 for contributions to thermal analysis and related materials research.
Special Recognition Award,
United States
A 2006 special-recognition award attributed in the existing biographical record to the National Academy of Television Arts and Sciences.
A 2006 special-recognition award attributed in the existing biographical record to the National Academy of Television Arts and Sciences.
