Nanotubules from a Self-Assembling Small Molecule

Abstract

ABSTRACTControl over the dimensions of nanostructured materials is of critical importance for proper utilization in devices. There has been a number of systems reported that utilize amphiphilic molecules that organize themselves into nanotubes or tubules, as well as various polymers that can assemble into tubular nanoscale structures. The organization of these components into nanotubes is mainly driven by hydrophobic effects of the substituents in particular solvents, which contain polar and apolar portions. While studying a modification to a previously reported GC module that normally forms rosette nanotubes (RNTs) with diameters in the 4nm range, we discovered that a small modification led to the formation of nanotubes with diameters 10 times of that expected. These structures were studied by SEM, TEM, and AFM in an attempt to uncover the mechanism of their formation. It was determined that these chiral organic molecules first self-assemble into sheet-like structures, but due to an inherent curvature of the sheet, they roll into large nanotubules. This new type of self-assembled nanotube may have applications in host-guest chemistry and as templates for other nanoparticles and materials.