title: Alignment of hexatic langmuir monolayers under shear.
abstract: We have studied the structural changes that fatty acid monolayers in the Ov phase undergo when a simple shear flow is imposed. A strong coupling is revealed by the changes in domain structure that are observable using Brewster angle microscopy, suggesting the possibility of shear alignment. The dependence of the alignment on the molecular polar tilt proves that the mechanism is different than in nematic liquid crystals. We argue that the degenerate lattice symmetry lines of the underlying pseudohexagonal lattice align in the flow direction, and we explain the observed alignment angle using geometrical arguments.
authors.affiliation: Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: J
authors.initials: J
authors.lastname: Ignés-Mullol
authors.forename: D K
authors.initials: DK
authors.lastname: Schwartz
mesh_terms: D005227:Fatty Acids / Q000737:chemistry*; D015394:Molecular Structure; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D005227:Fatty Acids