Top-down meets bottom-up: A comparison of the mechanical properties of melt electrospun and self-assembled 1,3,5-benzenetrisamide fibers

1,3,5-Benzenetrisamides (BTAs) are a prominent class of low-molecular weight compounds in supramolecular chemistry. They are well-known to self-assemble into micro- and nanofibers in a bottom-up approach. At the same time, BTAs are also suitable for top-down processing by melt electrospinning. In this work, we demonstrate for the first time that both approaches lead to mechanically robust BTA fibers. We compare self-assembled and electrospun fibers of N,N,N″-tripropyl-1,3,5-benzenetricarboxamide on multiple length scales. X-ray diffraction (XRD) reveals the same crystal structure independently from the preparation method. Using scanning electron microscopy (SEM), we observe significantly different morphologies of both fiber types on the sub-micron-scale. However, atomic force microscopy (AFM) bending experiments show that despite differences in morphology, Young's modulus is comparable for both types and in the lower GPa range (3-5 GPa). Thus, both top-down and bottom-up techniques with their complementary features in terms of accessible structures and potential applications are available for this class of materials.