Lyotropic nematics : molecular aggregation and susceptibilities
نویسندگان
چکیده
2014 Alterations of the concentrations of certain components in a lyotropic nematic mesophase may change the sign of the anisotropy of its magnetic susceptibility, 0394~. We report here : 1) the determination of the sign of 0394~ by optical observation of the textures in the presence of a magnetic field, 2) the results of an X-ray diffraction study of the aggregation of the amphiphilic molecules. We conclude that the inversion of 0394~ results from the different shapes of the aggregates. LE JOURNAL DE PHYSIQUE LETTRES TOME 40, 15 NOVEMBRE 1979,
منابع مشابه
Introduction to Liquid Crystals
1 What is a liquid crystal 2 1.1 Nematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2 Cholesterics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.3 Smectics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.4 Columnar phases . . . . . . . . . . . . . . ....
متن کاملCracks and topological defects in lyotropic nematic gels.
We report on the effects of the coupling of nematic order and elasticity in anisotropic lyotropic gels consisting of large nematic domains of surfactant coated single wall carbon nanotubes embedded in a cross-linked N-isopropyl acrylamide polymer matrix. We observe the following striking features: (i) undulations and then cusping of the gel sidewalls, (ii) a nematic director field that evolves ...
متن کاملAggregation, Pretransitional Behavior, And Optical Properties In The Isotropic Phase Of Lyotropic Chromonic Liquid Crystals Studied In High Magnetic Fields
Aggregation, pretransitional behavior, and optical properties in the isotropic phase of lyotropic chromonic liquid crystals studied in high magnetic fields a We report results on the high-field magneto-optical response of four aqueous, lyotropic, chromonic liquid crystal formulations in the isotropic phase. Measurements of the field-induced birefringence at temperatures above the isotropic-nema...
متن کاملElasticity-dependent self-assembly of micro-templated chromonic liquid crystal films.
We explore micropatterned director structures of aqueous lyotropic chromonic liquid crystal (LCLC) films created on square-lattice cylindrical-micropost substrates. The structures are manipulated by modulating the LCLC mesophases and their elastic properties via concentration through drying. Nematic LCLC films exhibit preferred bistable alignment along the diagonals of the micropost lattice. Co...
متن کاملControllable side-by-side and end-to-end assembly of Au nanorods by lyotropic chromonic materials.
We present a simple and universal technique for assembling gold nanorods (NRs) using self-assembled stacks of lyotropic chromonic materials, without covalent bonding between NRs and the linking agent. The anisotropic electrostatic interaction between the chromonic stacks and NRs allows one to achieve either side-by-side or end-to-end assembly, depending on the surface charge of NRs. The assembl...
متن کامل