(509g) Self-Assembly of Helical Tubules In Water Using a Single-Tailed Surfactant

Hollow micro or nanotubules are a remarkable type of self-assembled structure formed in aqueous solution. Self-assembled tubules may find applications in controlled release, drug delivery, and in electroactive composites. However, these structures are typically formed only by certain specific lipids (i.e., two-tailed amphiphiles), gluconamides or certain peptides. While the utility of tubules has been clearly shown, at the moment, their high cost limits their accessibility and applicability. Here we present an easy and inexpensive method for forming stable tubules in water by using a single-tailed diacetylenic acid surfactant in conjunction with an alcohol. We will describe the formation of tubules as a function of solution composition and temperature by using the techniques of optical and electron microscopy. Interestingly, the tubules show helical markings, which is unusual considering that the precursor molecules are achiral. This suggests that molecular chirality is not essential to form tubules, and this is in agreement with recent theoretical studies. The formation of tubules from achiral molecules is believed to proceed via a chiral symmetry-breaking process.