Refusing to twist: demonstration of a line hexatic phase in DNA liquid crystals
We report conclusive high resolution small angle x-ray scattering evidence that long DNA fragments form an untwisted line hexatic phase between the cholesteric and the crystalline phases. The line hexatic phase is a liquid-crystalline phase with long-range hexagonal bond-orientational order, long-range nematic order, but liquidlike, i.e., short-range, positional order. So far, it has not been seen in any other three dimensional system. By line-shape analysis of x-ray scattering data we found that positional order decreases when the line hexatic phase is compressed. We suggest that such anomalous behavior is a result of the chiral nature of DNA molecules.
Strey
HH
Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003 and NICHD/LPSB, National Institutes of Health, Building 12A/2041, Bethesda, Maryland 20892-5626, USA.
Wang
J
Podgornik
R
Rupprecht
A
Yu
L
Parsegian
VA
Sirota
EB