Triggering Gel-Sol Transition by Weak Magnetic Field

This is the authors' abstract. We don't add key points for this paper.

The self-assembly of small molecules into fiber-like structures is a mysterious process as the physics underlying such self-assembly is not clear. The energy necessary for this process exceeds the one provided by common dispersion interactions and hydrogen bonding. The recent results obtained by the scientific group of Prof. Naaman for the Weizmann Institute of Science fed light on the nature of the forces providing for the self-assembly of chiral molecules and attributed these forces to the spin exchange interactions. Therefore, the self-assembly of chiral molecules should be magneto-sensitive. We found such sensitivity in solutions of trifluoroacetylated alpha-aminoalcohols, and the process was inhibited by the magnetic field when fibers grew on the surface of the substrate. On the contrary, in the bulk, the self-assembly was enhanced by the magnetic field and led to the formation of the dense gel, while no gelation was observed in the absence of the external magnetic field. The latter observations are the theme of this short report aimed to declare the effect itself but does not pretend to describe it in full.