Title:	Two-dimensionally periodic phases in mixtures of compounds made of rodlike and bent-core molecules
Authors:	Pratibha, R. Madhusudana, N.V. Sadashiva, B.K.
Issue Date:	2005
Publisher:	The American Physical Society
Citation:	Physical Review E, 2005, Vol.71, 011701
Abstract:	We report two distinct types of two-dimensionally periodic phases in different concentration regions of a binary system composed of the bent-core (BC) compound 1,3-phenylenebis[4-(3-methylbenzoyloxy)]4[prime]-n-dodecylbiphenyl 4[prime]-carboxylate (BC12) and the rodlike (R) compound 4-n-octyloxy 4[prime]-cyanobiphenyl (8OCB). BC12 exhibits only the lamellar B2 phase. 8OCB which has a highly polar cyano end group exhibits the smectic-Ad phase with a lamellar structure of partial bilayers made of antiparallel pairs of the polar molecules. The molecular arrangements in the two-dimensionally periodic phases have been deduced based on optical microscopy, polarized infrared and x-ray diffraction studies. The arrangement in the two-dimensionally periodic phase in lower concentration ranges of BC12 (24 to 35 mol%) is dictated by the partial bilayer structure formed by the rods. The BC molecules arrange themselves with their arrow axes parallel to the long axes of the R molecules and the structure conforms to the c2mm space group symmetry. In higher concentration ranges of BC12 (35 to 60 mol%) the structure is dominated by the BC molecules, to form the familiar B1 phase with the p2mg space group symmetry. The R molecules lie at the interfaces of these domains stabilizing the structure.
URI:	http://hdl.handle.net/2289/1297
ISSN:	ISSN 1550-2376 (online) 1539-3755 (print)
Alternative Location:	http://link.aps.org/abstract/PRE/v71/e011701
Copyright:	(2005) by the American Physical Society
Appears in Collections:	Research Papers (SCM)

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