An X-ray scattering study of flow-aligned samples of a lyotropic liquid-crystalline hexagonal phase

被引:35
作者
Impéror-Clerc, M [1 ]
Davidson, P [1 ]
机构
[1] Univ Paris 11, CNRS, Phys Solides Lab, F-91405 Orsay, France
关键词
D O I
10.1007/s100510050745
中图分类号
O469 [凝聚态物理学];
学科分类号
070205 ;
摘要
Large flow-aligned samples of the hexagonal mesophase of the (sodium dodecylsulfate, pentanol, water) ternary system were produced by merely sucking the material into flat glass capillaries. These samples were examined by polarized light microscopy and X-ray scattering. In the plane of the hexagonal lattice, the "phi-mosaic" is only congruent to 0.1 degrees because the dense (10) hexagonal planes lie parallel to the flat glass plates of the capillaries. In contrast, the "chi-mosaic" of the C-6 axis reaches 5-10 degrees because the samples undergo a thermomechanical instability of the columns already investigated by Oswald et al. in detail on the (C12EO6, H2O) system. Anisotropic thermal diffuse scattering is observed around the Bragg peaks and its description in the frame of an elastic continuum model provides estimates of the elastic constants. On heating the samples, we observed a clear splitting of four of the (10) hexagonal lattice reflections. This splitting is the defining signature of the thermomechanical instability by which the columns form zig-zags. The fact that two of the (10) reflections are not affected by the instability demonstrates that it is confined to the plane of the capillary. The influence of temperature on the thermomechanical instability was also studied in detail.
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页码:93 / 104
页数:12
相关论文
共 43 条
[1]   INFLUENCE OF IMPERFECTIONS ON THE DISORDERING OF BLOCK-COPOLYMER CYLINDERS [J].
BALSARA, NP ;
DAI, HJ ;
KESANI, PK ;
GARETZ, BA ;
HAMMOUDA, B .
MACROMOLECULES, 1994, 27 (25) :7406-7409
[2]   INFLUENCE OF SHEAR ON THE HEXAGONAL-TO-DISORDER TRANSITION IN A DIBLOCK COPOLYMER MELT [J].
BATES, FS ;
KOPPI, KA ;
TIRRELL, M ;
ALMDAL, K ;
MORTENSEN, K .
MACROMOLECULES, 1994, 27 (20) :5934-5936
[3]   D2AM: A CRG beamline at ESRF for material science studies [J].
Berar, JF ;
Simon, JP ;
Ferrer, JL ;
Dalle, D .
EUROPEAN POWDER DIFFRACTION: EPDIC IV, PTS 1 AND 2, 1996, 228 :223-226
[4]   ABSOLUTE MEASUREMENT OF DIFFUSE-SCATTERING - DESCRIPTION OF AN INDEPENDENT DOUBLE CRYSTAL MONOCHROMATOR AND OF A VERSATILE 6 CIRCLE GONIOMETER ON A SYNCHROTRON SOURCE [J].
BESSIERE, M ;
BESSENAY, G ;
FROUIN, J ;
JOUVIN, M ;
LEFEBVRE, S .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 1987, 261 (03) :591-597
[5]   COLUMN BUCKLING INSTABILITY IN A DISCOTIC LIQUID-CRYSTAL [J].
CAGNON, M ;
GHARBIA, M ;
DURAND, G .
PHYSICAL REVIEW LETTERS, 1984, 53 (09) :938-940
[6]  
DAVIDSON P, 1995, J PHYS II, V5, P249, DOI 10.1051/jp2:1995127
[7]  
DEGENNES PG, 1993, PHYSICS LIQUID CRYST
[8]  
DEUDE S, THESIS U PARIS SUD O
[9]  
DURAND D, 1992, J PHYS II, V2, P1769, DOI 10.1051/jp2:1992233
[10]   SUPERMOLECULAR SELF ORGANIZATION VIA MOLECULAR AGGREGATION - NONDISCOTIC 3 CHAIN DIOLS DISPLAYING A HEXAGONAL COLUMNAR PHASE [J].
EBERT, M ;
KLEPPINGER, R ;
SOLIMAN, M ;
WOLF, M ;
WENDORFF, JH ;
LATTERMANN, G ;
STAUFER, G .
LIQUID CRYSTALS, 1990, 7 (04) :553-570