Stirring competes with chemical induction in chiral selection of Langmuir monolayer domains

• Main Authors: Petit-Garrido Nuria, Claret Josep, Ignés-Mullol Jordi, Sagués Francesc
• Format: Article
• Language: English
• Published: EDP Sciences 2013-08-01
• Series: MATEC Web of Conferences
• Online Access: http://dx.doi.org/10.1051/matecconf/20130404002

Chirality, the absence of mirror symmetry, can be equally invoked in relation to physical forces and chemical induction processes, yet a competition between these two types of influences is rarely reported. Here, we employ Langmuir monolayers of azobenzene surfactants as a prototypical self-assembled two-dimensional system in which chiral selection is controlled by the combined independent action of a chiral dopant and vortical stirring. The two effects can be arbitrarily coupled, either constructively or destructively, leading to a situation of perfect compensation. The induced enantiomorphic excess is measured in terms of the statistical imbalance of an ensemble of sub-millimeter monolayer domains, where achiral molecules self-assemble with a well-defined orientational chirality, which is unambiguously resolved using Brewster angle microscopy.