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Structure of the B4 Liquid Crystal Phase near a Glass Surface
Author(s) -
Chen Dong,
Heberling MichaelScott,
Nakata Michi,
Hough Loren E.,
Maclennan Joseph E.,
Glaser Matthew A.,
Korblova Eva,
Walba David M.,
Watanabe Junji,
Clark Noel A.
Publication year - 2012
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201100589
Subject(s) - nucleation , phase (matter) , liquid crystal , materials science , bent molecular geometry , crystallography , layer (electronics) , equidistant , transmission electron microscopy , crystal (programming language) , chemical physics , optics , molecular physics , geometry , composite material , chemistry , nanotechnology , optoelectronics , physics , mathematics , organic chemistry , computer science , programming language
The B4 liquid crystal phase of bent‐core molecules, a smectic phase of helical nanofilaments, is one of the most complex hierarchical self‐assemblies in soft materials. We describe the layer topology of the B4 phase of mesogens in the P‐n‐OPIMB homologous series near the liquid crystal/glass interface. Freeze‐fracture transmission electron microscopy reveals that the twisted layer structure of the bulk is suppressed, the layers instead forming a structure with periodic layer undulations, with the topography depending on the distance from the glass. The surface layer structure is modeled as parabolic focal conic arrays generated by equidistant parabolas whose foci are defect lines along the glass surface. Nucleation and growth of toric focal conics near the glass substrate is also observed. Although the growth of twisted nanofilaments, the usual manifestation of structural chirality in the B4 phase, is suppressed near the surface, the smectic layers are intrinsically chiral, and the helical filaments that form on top of them grow with specific handedness.