Article ID: 2016-0034
Direct observation of a polymer chain deepens the understanding about its structure and function. The study of single-polymer-chains was made possible after the scanning probe microscope (SPM) and the total internal reflection fluorescent microscope (TIRFM) had been developed. The author succeeded in the direct observation of the long-chain branch (LCB) structure in a low density polyethylene (LDPE), and the structural dynamics of a polymer chain in a functionalized styrene-butadiene rubber (SBR) and an ethylene-propylene (EP) rubber measured by a fast-scanning atomic force microscope (FS-AFM). Single-molecule imaging of a macromolecular motion in a chiral helical polymer was achieved by the FS-AFM, and the diffusion coefficient of each part of the polymer chain was measured. Furthermore, a molecular walking along a rail of a synthetic helical polymer was discovered. This walking such as a crawling locomotion was observed by the FS-AFM in an organic solvent at room temperature. This result is a breakthrough that serves as the first step in order to create an artificial life function as a synthetic molecular motor driven by a thermal fluctuation in non-aqueous media. On the other hand, the photonic function of the light-emission from a rigid-rod conjugated polymer was measured using TIRFM at room temperature. The light-emission from a single polymer chain as it slowly and dynamically changes over a cycle lasting a few seconds has been successfully detected using TIRFM with a built-in spectroscope.
