Correlation of the hierarchical structure with rheological behavior of polypseudorotaxane gel composed of pluronic and β-cyclodextrin. Issue 21 (21st May 2020)

• Record Type: Journal Article
• Authors: Shih, Kuo-Chih; Su, Chien-You; Chang, Shing-Yun; Jensen, Grethe; Hua, Chi-Chung; Nieh, Mu-Ping; Lai, Hsi-Mei
• Is Part Of: Soft matter. Volume 16:Issue 21(2020)
• Page Start: 4990
• Page End: 4998
• Publication Date: 2020-05-21
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/d0sm00406e
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : The reorganization of meso-structured "grains" composed of multiple lamellar stacks strung by F108 results in thixotropic properties. Abstract : We have identified the hierarchical (primary, secondary, tertiary and quaternary) structures of a polypseudorotaxane (PPR) gel composed of the Pluronic F108 and β-cyclodextrin system to be β-cyclodextrin crystalline, lamellar sheets, lamellar stacks and "grains", respectively. The correlation between the rheological properties and the proposed structures under shear flows was rationalized. Alignment of lamellar stacks and reorganization of grain boundaries under shear flows were investigated by rheo-SANS, small angle X-ray scattering and small-angle light scattering. The relaxation of highly aligned lamellar stacks is slow (>2 h) after flow cessation compared to that of the regrouped grains (a few minutes). The main contribution to thixotropic behavior is likely from the faster relaxation of the reorganized grains containing highly oriented lamellar stacks. The comprehensive understanding of structure–function relationship of the PPR gel will facilitate the rational design for its applications.