MICROSCOPIC HETEROGENEITY IN VISCOELASTIC PROPERTIES OF MOLECULAR ASSEMBLED SYSTEMS  

作　　者：Atsuomi Shundo David P. Penaloza Keiji Tanaka 

机构地区：[1]Department of Applied Chemistry,Kyushu University [2]International Institute for Carbon-Neutral Energy Research (WPI-I2CNER),Kyushu University

出　　处：《Chinese Journal of Polymer Science》2013年第1期1-1,2-11,共11页高分子科学（英文版）

基　　金：supported by Grant-in-Aid for Scientific Research (B) (No. 24350061) from the Ministry of Education, Culture, Sports, Science and Technology, Japan

摘　　要：An important step in understanding molecular assembled systems is to examine the structure and physical properties at various length scales and clarify the correlation between them. However, while the structures of these systems have been extensively studied from nanoscopic to macroscopic scales, their viscoelastic properties have been often limited to bulk rheological measurements. By using optical tweezers and particle tracking, we here show the local viscoelastic properties and their spatial distributions for the following systems： worm-like micelle solution, supramolecular hydrogel and lyotropic liquid crystal, which are formed by self-assembly of amphiphilic molecules in water. We found that all systems studied possessed a spatial heterogeneity in their viscoelastic properties and this was originated from the heterogeneous structures. It is interesting to note that there is the heterogeneity with the characteristic length scale of sub-micrometer or micrometer scale, thereby structures, although the systems are formed by molecules with nanometer size. The findings of these studies should lead to a better understanding of the dynamics of such systems.An important step in understanding molecular assembled systems is to examine the structure and physical properties at various length scales and clarify the correlation between them. However, while the structures of these systems have been extensively studied from nanoscopic to macroscopic scales, their viscoelastic properties have been often limited to bulk rheological measurements. By using optical tweezers and particle tracking, we here show the local viscoelastic properties and their spatial distributions for the following systems： worm-like micelle solution, supramolecular hydrogel and lyotropic liquid crystal, which are formed by self-assembly of amphiphilic molecules in water. We found that all systems studied possessed a spatial heterogeneity in their viscoelastic properties and this was originated from the heterogeneous structures. It is interesting to note that there is the heterogeneity with the characteristic length scale of sub-micrometer or micrometer scale, thereby structures, although the systems are formed by molecules with nanometer size. The findings of these studies should lead to a better understanding of the dynamics of such systems.

关 键 词：Optical tweezers Soft materials HETEROGENEITY Hierarchical structure Rheological properties. 

分 类 号：O631.1[理学—高分子化学]