My Research Interests

I have been studying (A list is availble here) molecular structure in organic ultra-thin films by using spectroscopic techniques. Most of these films were usually assembled by the Langmuir-Blodgett (LB) method. To analyze molecular orientation in the films, I employed infrared external reflection (ER) spectroscopy. The polarized spectra of the films often show quite complex features, particularly those with negative reflection absorbance. I developed an interesting theory that can take the uniaxial optical anisotropy in LB film into account easily.

My most recent research interest is as below:

  1. Analysis of condensed matters and thin films by vibrational spectroscopy
    Is science of condensed matters physics or chemistry? In recent ten years, this field has moved onto a borderline between physics and chemistry. No, we must not devide science into physics and chemistry!! They are intrinsically on both sides of one thing. They always require each other. Condensed matters and thin films sound most interesting examples for the field. Many chemists are intested in development of novel functionalized films, while people who are major in physics are involved in the analysis of surface structure and optical properties of the films.
    Analysis of dielectric dispersion of condensed matters is a bridge between structural study related to chemistry and material characterization related to physics. In particular, infrared and Raman spectroscopies are very informative methods to investigate both structure and properties of the matters. Our group has recently develped a novel method that enables us to evaluate molecular orientation and dielectric dispersions in films. With this method, highly complex materials that have been not studied well in the physical field are expected to be good targets for our studies.
  2. Chemometrics and 2D-analysis of Spectra
    The 20th century was a era of great progress of both molecular theory and spectroscopic techniques. In 1950s, the measurements of infrared spectra were very tough works, and the measurements were performed in very limited places. In Kyoto, for example, young Professor Takenaka and his colleagues constructed an infrared spectrophotometer with the use of a thermocouple with no electric amplifier. The apparatus was quite primitive from our point of view, but a great number of measurement requests assembled to them.

In recent years, however, everyone can use a greatly progressed Fourier transform infrared (FT-IR) spectrometer, and measurements of ultrathin-layer films can be carried out even by undergraduate students quite easily.

Although the measurements are very easy, the analysis and understading of the spectra are still difficult. Vibrational spectra have a number of bands, and many of them are overlaid on eath other, which makes it difficult to analyze them.

Chemometric techniques that are multivariate techniques of spectral analysis were introduced about thirty years ago to draw quantitative information from the complicated spectra. The techniques progressed largely, and spectra resolution was also developped by the techniques.

2D-correlation analytical technique of spectra was developped by Dr. Isao Noda with his colleague, Dr. Marcott, P&G, Cincinnati, independent to the history of chemometrics. This technique provides us with fine band information especially some bands are overlapped with each other. It has been recognized that 2D technique is very powerful to analyze dynamic FT-IR spectra of polymer with sinusoidal strains, and spectra after collection of several spectra with external perturbation.

Nonetheless, the deep insights in the relationship between chemometrics and 2D techniques are still not uncleaer. Both thchniques should be studied more to fully draw molecular information from observed spectra. It is a problem that there is a gap between the communities of vibrational spectroscopy and chemometrics. We have to understand both of them.

  1. Molecular Recognition
    Molecular recognition is a very exciting topic. In biological system, molecular recognition plays a important role in many functional molecules. In the study of chromatography, molecular recognition is an inevitable phenomenon to understand effective molecular separation.
    However, the spectroscopic study of molecular recognition has been difficult, because of complicated spectra. Now, I am ready to start this spectroscopic study using various measurement, and analytical techniques.