Orientation and optical property

Kim, J. C Cakmak, M. and Zhou, X Effect of composition on crystalline orientation and optical properties of biaxially stretched PEN/PEI films, in Proceedings of the 55th SPE ANTEC 97 Conference, May 5-8, 1997, Toronto, ON, Canada, Society of Plastics Engineers, Brookfield, CT, 1997, Vol. 2, pp. 1588-1592. 

Boamfa et al. investigated macroscopic orientation of disubstituted cyano-biphenyl poly(norbornene) IV-n (n=3,5) using different magnetic fields of up to 20 T. Both the degree of orientation and optical properties were compared with a cyanobiphenyl-substituted acrylate polymer with a spacer of four methylene units [49,50]. 

Various matrix representations have been contrived to represent the orientation and optical properties of individual domains. The incident polarized light is resolved into "horizontal" and "vertical" components relative to die same reference axes, and is represented by a column matrix. The final polarization state is then calculated by matrix multiplication ... 

Molecular Multilayer Films The Quest for Order, Orientation, and Optical Properties... 

Lere-Porte, J.-R, J.J.E. Moreau, F. Serein-Spirau, G. Torreilles, A. Righi, J.-L. Sauvajol, and M. Brunet. 2000. Synthesis, orientation and optical properties of thiophene-dialkoxyphenylene copolymers. / Mater Chem 10 927-932. 

The subscripts denote the dimension of the matrices. The denominator in Eq. 2.6b results from the fact that scattering detection is made at some distance, r, from the scattering center. The amplitude functions are functions of the size, shape, orientation, and optical properties of the particle and of the scattering angle. Once the amplitude functions are determined, one can obtain from the matrix F characteristics of the scattered light. In the cases when both S3 and S4 are nil, the relationships between the incident and scattered light intensities are simple ... 

When drawdown is high, the film may be uniaxially oriented and the properties of the final film isotropic. In the manufacture of strapping tape this effect is accentuated. If the cast or quenched film is to be used to feed an orientation tine, additional attention must be given to the amorphous—crystalline nature of the film ia the draw processes so that maximum strength can be achieved and uniform gauge and optical quality maintained. Slot casting is used for the orientation of these resins, polyesters, polyamides, and a variety of others. 

Thin-film XRD is important in many technological applications, because of its abilities to accurately determine strains and to uniquely identify the presence and composition of phases. In semiconduaor and optical materials applications, XRD is used to measure the strain state, orientation, and defects in epitaxial thin films, which affect the film s electronic and optical properties. For magnetic thin films, it is used to identify phases and to determine preferred orientations, since these can determine magnetic properties. In metallurgical applications, it is used to determine strains in surfiice layers and thin films, which influence their mechanical properties. For packaging materials, XRD can be used to investigate diffusion and phase formation at interfaces... 

Processes such as film extrusion, fiber spinning, injection molding, and drawing tend to impart orientation to products made from semicrystalline polymers. Mechanical, dielectric, and optical properties, to mention only three, are often strongly influenced by orientation. X-ray diffraction offers a direct approach to studying crystallite orientation because the Intensity that is diffracted into a detector placed at an appropriate position is directly proportional to the number of crystal lattice planes that are in the correct orientation for diffraction. The principles of such measurements are well described in textbooks 0,2). 

When a strong static electric field is applied across a medium, its dielectric and optical properties become anisotropic. When a low frequency analyzing electric field is used to probe the anisotropy, it is called the nonlinear dielectric effect (NLDE) or dielectric saturation (17). It is the low frequency analogue of the Kerr effect. The interactions which cause the NLDE are similar to those of EFLS. For a single flexible polar molecule, the external field will influence the molecule in two ways firstly, it will interact with the total dipole moment and orient it, secondly, it will perturb the equilibrium conformation of the molecule to favor the conformations with the larger dipole moment. Thus, the orientation by the field will cause a decrease while the polarization of the molecule will cause an... 

A novel procedure, called LISIM (Linear Motor Simultaneous Stretching) technique, for the manufacture of expanded, biaxiaUy oriented films of PP and propylene copolymers, is reported. Examples, which demonstrate the the range of possibilities for varying the final film properties through formulations, machine settings and processing are demonstrated and the mechanical and optical properties of expanded films made by the above technique tabulated. (Kunststoffe, 91, No.l 1,2001, p.68-73)... 

The principle uses of the zinc borate Zn[B304(0H)3] are as a polymer additive and preservative for wood composites, such as oriented strand board (OSB). As a polymer additive it functions as a fire retardant synergist and modifier of electrical and optical properties. Its function as a fire retardant additive is discussed further below. A substantial amount of Zn[B304(0H)3] is used to improve the tracking index, which is an important performance criterion for polymers, such as polyamides (nylon) and polybutyl teraphtha-lates (PBT), used in electrical applications. 

Crushing has been recommended as a primary method because it is safe and will lead to the determination of the principal refractive indices of any crystalline substance, provided a sufficient number of randomly oriented fragments is observed it is a beginner s method. But the more experienced worker may often dispense with it, when the crystals being examined have a well-defined polyhedral shape. If the relation between crystal shape and optical properties is properly understood, it is possible to determine the principal indices by a limited number of observations on crystals selected because they lie in such positions that they necessarily show their principal indices. 

Suspensions and dispersions of particles are characterized by distributions describing their orientation and spatial distribution. Knowledge of these distributions then allow the calculation of bulk mechanical and optical properties. In the following sections, theories are presented for both dilute and semidilute systems. 

This section will demonstrate the first sergeants and soldiers-type helix command surface experiment, in which thermo-driven chiroptical transfer and amplification in optically inactive polysilane film from grafted (or spin-coated) optically active helical polysilane onto quartz substrate [92]. Although helix and optical activity amplification phenomena based on the sergeants and soldiers principle was mainly investigated in polymer stereochemistry, the orientation and physical properties of a thick layer deposited onto a solid surface and controlled by a monolayer command film based on command surface principles was established in photochemical material and surface science [93,94]. Both sergeants and soldiers and command surface experiments appear to have been developed independently. 

In conclusion, for both AP-CVD and LP-CVD processes, only a narrow range of temperatures can be identified for optimum performance (a range that is typically 40°C-wide). Within this narrow temperature range highly oriented films are obtained that have electrical and optical properties suitable to act as transparent conductors in solar cells. The typical substrate temperature is around 400°C for the AP-CVD process, whereas it is around 160°C for the LP-CVD process. The two processes yield film orientations that are perpendicular to each other. 

The apparatus used for IR microscopy is a Fourier-transform infrared (FTIR) spectrometer coupled on-line with an optical microscope. The microscope serves to observe the sample in white light at significant magnification for the purpose of determining its morphology, as well as to select the area for analysis. The spectrometer, on the other hand, enables study of the sample by transmission or reflection measurement for the purpose of determining the chemical composition. It also provides information about the microstructure and optical properties (orientation) of the sample. It is possible to apply polarised light both in the observation of the sample and in spectrometric measurements. 

It is well known that the electrical and optical properties and the performance of the electronic and optoelectronic devices based on inorganic nanostmctured materials critically depend on the composition, crystalline stmcture, and orientation hence, these parameters must be known for nanostmctures integrated into... 

Organized azo-molecular assemblies allow for the study of photoisomerization and photo-orientation in sterically and orientationally well-defined media, such as LBK multilayers, the molecular-interactions-based order of which can be altered by photoisomerization of the azo units.In this chapter, we also discuss the photoisomerization-induced changes in the structural and optical properties of highly organized organic films containing azobenzenes. Photoisomerization and photo-orientation of azobenzenes is compared in amorphous spin-cast films, in LBK supramolecular assemblies, and in self-assembled monolayers. 

Yamamoto, T., Fang, Q., and Morikila, T. 2003. New soluble poly(aryleneethynylene)s consisting of electron-accepting benzothiadiazole units and electron-donating dialkoxybenzene units. Synthesis, molecular assembly, orientation on substrates, and electrochemical and optical properties. Macromolecules 36,4262-4267. 

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