2023 年 7 巻 p. 10-17
In previous study, it was found that the refractive index of pure water is lower during the microwave irradiation because hydrogen bond network collapses due to the strong vibration and the rotation. In this study, refractive index of glucose aqueous solution was measured during the microwave pulse irradiation. When irradiation of pulse mode was carried out, the refractive index increased step-wisely due to the quick response of microwave. Because the temperature dependence of the refractive index of the aqueous solution is negative, the microwave effect for intermolecular structure, which is closely related with refractive index, was confirmed. In the case of the higher concentration, the refractive index increased during the irradiation because the intermolecular structure between aggregated glucose molecules and water molecules is changed. In particular, molecular structure caused by the irradiation was not fully re-constructed during the interval. For example, pulse irradiation mode can maintain molecular structure caused by microwave for a long time when the interval is 20-60 seconds.