Structural analysis of slide-ring gel by small angle X-ray scattering and control of the pulley effect

The slide-ring gel is synthesized by cross-linking α-cyclodextrins contained in the sparse polyrotaxanes in solutions. The polymer chains in the slide-ring gel freely pass through the cross-links acting like pulleys, which is supposed to automatically equalize the nanoscopic heterogeneity in structure and stress. In this study, we report the SAXS patterns on uniaxially stretched slide-ring gels in good or poor solvents. Topological gel showed the normal butterfly pattern in good solvents in which pulley effect is active, and showed the abnormal butterfly pattern in poor solvents. This indicates that the aggregation in poor solvent suppresses the sliding of cross-links considerably, which enabled us to control the pulley effect freely by varying the solvent. Furthermore, we found out that ellipticity of the pattern of slide-ring gel was small compared with that of chemistry gel at same elongation ratio.