Isotropic glass

Poly Si RIE Low-pressure chemical vapor deposition Glass isotrope... 

Ellipsometry of the Glass-Isotropic Nematic Liquid Crystal Interface... 

Chromium/ Gold Wet chemical etching Cathode sputtering Glass isotrope... 

Glass is the name given to any amorphous solid produced when a liquid solidifies. Glasses are non-crystalline and isotropic, i.e. their physical properties are independent of the direction in which they are measured. When a glass is heated, it does not melt at a fixed temperature but gradually softens until a liquid is obtained. 

Laminates. Two or more layers of material bonded together form a laminated composite. Common examples of laminates are in automobile windshields (laminated glass) and bimetal thermostats (9). In both cases homogeneous, isotropic layers of materials are bonded together to form nonhomogeneous composite laminates (see Laminates). 

Conventionally RAIRS has been used for both qualitative and quantitative characterization of adsorbed molecules or films on mirror-like (metallic) substrates [4.265]. In the last decade the applicability of RAIRS to the quantitative analysis of adsorbates on non-metallic surfaces (e.g. semiconductors, glasses [4.267], and water [4.273]) has also been proven. The classical three-phase model for a thin isotropic adsorbate layer on a metallic surface was developed by Greenler [4.265, 4.272]. Calculations for the model have been extended to include description of anisotropic layers on dielectric substrates [4.274-4.276]. 

Isotropic Refers to materials whose properties are the same in all directions. Examples are metals and glass mats. 

Focusing attention on PTEB, it has been found that, similar to the case of PDTMB, the mesophase experiences a very slow transformation into the crystal. Thus, only the isotropization is observed in a sample freshly cooled from the melt [27]. However, after a long time at room temperature, the transformation mesophase-crystal is produced, owing to a glass transition temperature of about 14°C. Moreover, several endotherms were obtained before the final isotropization for a sample of PTEB annealed at 85°C for 12 days, i.e., PTEB shows enantiotropic behavior. The different endotherms may arise from polymorphism or melting-recrystallization phenomena [30]. 

Figure 16-29. Polnri/.cd-lighl oplicnl micrographs of i [hill (200 mil) rilm of Oocl-OPVS vucuuin-dcposilcd oiilo a glass substrate. A as-deposited li annealed lor 5 min al 120 C C oblained after slow cooling horn ihc isotropic niell al 210 C. Seale bar 100 pm.

Bodies in which the physical properties are identical in all directions e.g., glass, air, water. This class of bodies includes all gases, most liquids, and the so - called amorphous solids such as glasses (that is, solids showing no external crystalline form, and breaking with a glassy fracture). Bodies of this type are called Isotropic Bodies. 

Continuous transition of state is possible only between isotropic states it may thus occur between amorphous glass (i.e., supercooled liquid of great viscosity) and liquid ( sealing-wax type of fusion ), or between liquid and vapour, but probably never between anisotropic forms, or between these and isotropic states. This conclusion, derived from purely thermodynamic considerations, is also supported by molecular theory. 

Fig. 18. Plot of residual depth parameter as a function of the ratio H/E according to equation 10. A value of v = 0.41 is taken for PE. Data for die-drawn PE (O) and POM ( ) and for soda-glass (A) and hard-steel (A) are shown. H/E values for lamellar isotropic PE with a 200 A thick surface (ft) and isotropic chain-extended material (1 2 x 103 A) (f) are also indicated...

Liquid crystalline solutions as such have not yet found any commercial uses, but highly orientated liquid crystal polymer films are used to store information. The liquid crystal melt is held between two conductive glass plates and the side chains are oriented by an electric field to produce a transparent film. The electric field is turned off and the information inscribed on to the film using a laser. The laser has the effect of heating selected areas of the film above the nematic-isotropic transition temperature. These areas thus become isotropic and scatter light when the film is viewed. Such images remain stable below the glass transition temperature of the polymer. 

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