Nano- and microstructure fabrication by using a three-component system

Abstract

Two-component amphiphiles based on hydrogen-bonded complexes between terephthaloylbisalanine (H2TBA) and dodecylamine (DA) are able to self-assemble into nano- and microsized superstructures in an aqueous solvent. It is possible to modulate the morphology of these self-assembled superstructures by modifying the composition of the complexes, which can be achieved by changing the molar ratio of the two components or by changing the chirality of H2TBA. For example, right-handed microhelical ribbon structures were formed with L-TBA1.0,DA2.0, whereas in the case of rac-TBA1.0DA2.0, flat ribbonlike structures were observed. Although L-TBA1.0DA1.0 exhibited entangled fibrous structures, rac-TBA1.0DA1.0 exhibited wire structures. Different ratios of H2TBA and DA were self-assembled into fiber-, wire-, and tubulelike superstructures, as well as monoclinic, columnar, and lamellar aggregation patterns. The self-assembled superstructures of TBAxDAy were significantly changed by adding metal ions. Transition metal (CdII, CoII, and ZnII) complexes with L-TBAxDAy, self-assembled into rod-, tubule-, wire-, and platelike superstructures. Metal-ion complexes with rac-TBAxDAy exhibited different superstructures. Our work suggests that it is possible to fabricate a wide variety of nano- and microsized superstructures by using two- and three-component amphiphiles. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.