Terahertz Dynamics of Carboxymethyl Starch*

We performed terahertz time-domain spectroscopy on microwave-treated sodium carboxymethyl starch (CM-Starch), to detect the boson peak and fracton. Starch is a natural polymer formed by polymerization of a number of D-glucose molecules by glycosidic linkage and CM-Starch is produced by carboxymethylating the starch. The obtained spectral shape of boson peak plot α(ν)/ν² of the CM-Starch, where α(ν) is the absorption coefficient, is different from vitreous glucose. It suggests the existence of the fracton in the CM-Starch.