Producing supramolecular functional materials based on fiber network reconstruction

Abstract

Here, the creation of new supramolecular functional materials based on the reconstruction of three-dimensional interconnecting self-organized nanofiber networks by a surfactant is reported. The system under investigation is N-lauroyl-L-glutamic acid di-n-butylamide in propylene glycol. Thearchitecture of networks is implemented in terms of surfactants, e.g. sorbitan monolaurate. The elastic performance of the soft functional material is either weakened or strengthened (up to 300% for the current system) by reconstructing the topology of a fiber network. A topology transition of gel fiber network from spherulite-like to comb-like to spherulite-like is performed with the introduction of this surfactant. The Span 20 molecules are selectively adsorbed on the side surfaces of the crystalline fibers and promote the nucleation of side branches, giving rise to the transformation of the network architecture from spherulite-like topology to comb-like topology. At high surfactant concentrations, the occurrence of micelles may provide an increasing number of nucleation centers for spherulitic growth, leading to the reformation of spherulite-like topology. An analysis on fiber network topology supports and verifies a perfect agreement between the topological behavior and the rheological behavior of the functional materials. The approach identified in this study opens up a completely new avenue in designing and producing self-supporting supramolecular functional materials with designated macroscopic properties. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.