Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Magnetic mesophase anisotropy

Since most liquid crystalline phases used today are lyotropic mesophases with a relatively small magnetic susceptibility anisotropy, it should be noted that the orientation of the director is also influenced by the inertial torque when... [Pg.209]

Note 3 For mesophases eomposed of cylindrically symmetric molecules there is a precise relationship between the magnetic anisotropy, A, and the second-rank orientational parameter P ). [Pg.130]

Ageing of this sample at higher temperature (105 C) led to anisotropy in its ESR spectrum with an amplitude of anisotropy of 0,9 mT [12]. The average g-value of the anisotropy spectrum is equal to that of isotropic spectrum. Anisotropy observation under conditions of intermolecular exchange of unpaired electrons is possible only in the case of mutual orientation of the main molecular axes of paramagnetic domains located in high ordered mesophase structures [13] This leads to a preferential orientation of PMS with respect to the magnetic fields. [Pg.1175]

Orientational order plays an important role in solid polymers. It is often induced by industrial processing, for example in fibers and injection- or compression-modulated parts. In polymers with liquid-crystalline properties of the melt or solution, the anisotropies generated by the flow pattern are particularly pronounced. In order to improve the mechanical properties of polymer fibers or films, the degree of orientation is intentionally enhanced by drawing. At the same time, anisotropy of mechanical properties can result in low tolerance to unfavourably directed loads. In many liquid-crystalline polymers, in the mesophase near the transition to the isotropic phase, electric or magnetic fields can induce macroscopic orientational order [1]. Natural polymers such as silk protein fibers, which are biosynthesized and spun under biological condition, also have good mechanical properties because of their ordered structure [2]. [Pg.307]

Chapter 6 heralds the second part of the book and introduces the reader to anisotropy of the magnetic and electric properties of mesophases. Following in Chapter 7 there is a focus on the anisotropy of transport properties, especially of electrical cOTiductivity. Without these two chapters (Chapters 6 and 7), it would be impossible to discuss electro-optical properties in the third section of the book. Further, Chapters 7 and 8 deal with the anisotropy of the properties of elasticity and viscosity. Chapter 8 is more difficult than the others, and in order to present the theoretical results as clearly as possible, the focus is on the experimental methods for the determinatimi of Leslie viscosity coefficients from the viscous stress tensor of the nematic phase. Chapter 9 terminates the discussion of the anisotropy of... [Pg.450]

Liquid crystals are fluids in which there occurs a certain order in the arrangement of the molecules. As a result, there is anisotropy in the mechanical, electrical, magnetic, and optical properties. Although liquid crystals, or mesophases, combine the properties of a solid and an isotropic liquid, they exhibit very specific electrooptical phenomena. As a rule these have no corresponding analogues in solids or in isotropic liquids. [Pg.477]


See other pages where Magnetic mesophase anisotropy is mentioned: [Pg.144]    [Pg.144]    [Pg.305]    [Pg.71]    [Pg.119]    [Pg.450]    [Pg.138]    [Pg.140]    [Pg.475]    [Pg.70]    [Pg.112]    [Pg.286]    [Pg.102]    [Pg.110]    [Pg.111]    [Pg.114]    [Pg.114]    [Pg.116]    [Pg.121]    [Pg.122]    [Pg.125]    [Pg.384]    [Pg.122]    [Pg.131]    [Pg.210]    [Pg.65]    [Pg.372]    [Pg.542]    [Pg.230]    [Pg.51]    [Pg.127]    [Pg.128]    [Pg.129]    [Pg.130]    [Pg.130]    [Pg.130]    [Pg.135]    [Pg.137]    [Pg.610]    [Pg.113]    [Pg.139]    [Pg.81]    [Pg.298]    [Pg.39]   


SEARCH



Magnet anisotropy

Mesophase

Mesophases

© 2024 chempedia.info