Small angle neutron scattering (SANS) studies on the structural evolution of pyromellitamide self-assembled gels
No Thumbnail Available
Date
2014-10-31
Journal Title
Journal ISSN
Volume Title
Publisher
ACS Publications
Abstract
The kinetics of aggregation of two pyromellitamide gelators, tetrabutyl- (C4) and tetrahexyl-pyromellitamide (C6), in deuterated cyclohexane has been investigated by small angle neutron scattering (SANS) for up to 6 days. The purpose of this study was to improve our understanding of how self-assembled gels are formed. Short-term (< 3 h) time scales revealed multiple phases with the data for the tetrabutylpyromellitamide C4, indicating one-dimensional stacking and aggregation corresponding to a multifiber braided cluster arrangement that is about 35 Å in diameter. The corresponding tetrahexylpyromellitamide C6 data suggest that the C6 also forms one-dimensional stacks but that these aggregate to a thicker multifiber braided cluster that has a diameter of about 62 Å. Over a longer period of time, the radius, persistence length, and contour length all continue to increase in 6 days after cooling. These data suggest that structural changes in self-assembled gels occur over a period exceeding several days and that fairly subtle changes in the structure (e.g., tail-length) can influence the packing of molecules in self-assembled gels on the single-to-few fiber bundle stage © 2014, American Chemical Society.
Description
Keywords
Kinetics, Cyclohexane, Data, Fibers, Tetralin, Molecules
Citation
Jamieson, S. A., Tong, K. W. K., Hamilton, W. A., He, L., James, M., & Thordarson, P. (2014). Small angle neutron scattering (SANS) studies on the structural evolution of pyromellitamide self-assembled gels. Langmuir, 30(46), 13987-13993. doi:10.1021/la502546n