Terraces in the cholesteric phase of DNA liquid crystals

Journal Article · Thu Oct 15 04:00:00 EDT 1992 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.463772· OSTI ID:7018056

Van Winkle, D H ^[1]; Davidson, M W ^[2]; Rill, R L ^[3]

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1. Department of Physics and Center for Materials Research and Technology, The Florida State University, Tallahassee, Florida 32306-3016 (United States)
2. Center for Materials Research and Technology and Institute of Molecular Biophysics, The Florida State University, Tallahassee, Florida 32306-3006 (United States)
3. Department of Chemistry and Institute of Molecular Biophysics, The Florida State University, Tallahassee, Florida 32306-3006 (United States)

Near the transition to the columnar phase, the cholesteric liquid crystal phase in an aqueous solution of DNA fragments with contour lengths approximating the persistence length undergoes an unwinding of the cholesteric pitch. Unwinding of the cholesteric with planar alignment of the fragments was studied by polarized light microscopy. Terraces or Grandjean planes'' of cholesteric are seen as uniformly birefringent fields of distinct hues (typically blue), bounded by lines which moved as the local concentration of DNA increased. These lines are interpreted as disclination lines, bounding regions of different total twist, which move as the intrinsic pitch of the cholesteric varies with concentration.

• OSTI ID: 7018056
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 97:8; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
550200 -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
AQUEOUS SOLUTIONS
BIREFRINGENCE
CONCENTRATION RATIO
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
CRYSTALS
DISPERSIONS
DNA
FLUIDS
LIQUID CRYSTALS
LIQUIDS
MICROSCOPY
MIXTURES
NUCLEIC ACIDS
OPTICAL MICROSCOPY
ORGANIC COMPOUNDS
PHASE TRANSFORMATIONS
POLARIZATION
REFRACTION
SOLUTIONS
VARIATIONS