Birefringence in polymers
WebOptical Birefringence Analysis. Optical birefringence provides an image with spaced colored zones that relates to the stress distribution that exists within the sample that is … WebAbstract. A comparison between the efforts which have been made in characterizing flow properties of polymer melts with the aid of mechanical and optical measurements, shows that a lot more interesting work can be done in the latter field. One of the aims of the present compilation is to show how helpful flow birefringence measurements can be ...
Birefringence in polymers
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WebMar 25, 2016 · 2 Introduction When non-branched linear polymers such as polyethylene (PE) crystallizes from the melt, formation of sphere-shaped semicrystalline areas occurs. 1 These ordered regions, just like the grains in metals and ceramics, inside non-branched linear polymers are called spherulites. 2 A spherulite has a diameter ranging from 1 to … WebFeb 1, 2006 · The major causes of severe birefringence can be divided into two main categories: (1) the difference in the cooling rate inside the polymer when the cooling rate of the polymer melt is increased ...
WebApr 5, 2024 · The thin films exhibit a negative birefringence for a vast majority of the investigated wavelengths, e.g., Δn = −0.17 at λ = 600 nm for the active material, which shows that the molecular polarizability is higher in the thin-film plane than in the direction perpendicular to the same plane. For polymers, the molecular polarizability, and ... WebMar 31, 2000 · When birefringence is on the order of the change of the in-plane refractive index between adjacent material layers, surprising and useful optical effects occur. We refer to these effects as giant birefringent optics (GBO). A central feature of GBO is improved control of the reflectivity of p-polarized light.
WebMay 6, 2013 · Either some polymers are still covering some parts of the lipids in a conformation with a positive birefringence, or some polymer did not have enough space to take up its fully extended conformation on the bare surface (see Figure 6). Both scenarios would increase the calculated values of the positively anisotropic areas. WebAbstract. A comparison between the efforts which have been made in characterizing flow properties of polymer melts with the aid of mechanical and optical measurements, …
Web3.In order to improve the technique of making microstructure on azobenzene polymer film, a new experimental method is presented, based on photoinduced isomerization and photoinduced birefringence of an amorphous copolymer containing azobenzene groups.为了提高制作偶氮苯微结构的实验技术 ,在偶氮苯聚合物的光致异构和光 ...
WebGiant Birefringent Optics in Multilayer Polymer Mirrors Michael F. Weber, Carl A. Stover, Larry R. Gilbert, Timothy J. Nevitt, Andrew J. Ouderkirk* Multilayer mirrors that maintain or increase their reßectivity with increasing in-cidence angle can be constructed using polymers that exhibit large birefringence in their indices of refraction. soins tracheotomieWebMar 24, 2014 · Birefringence is a phenomenon to cause two refracted rays of light when a ray of light enters an optically anisotropic material. The … soins thermauxWebJan 3, 2024 · The two-level optical birefringence is dependent on the molecular weight and polymer concentration in the morphology diagram and is proven a general phenomenon in more kinds of semicrystalline polymers. soin strasbourgWebJan 1, 2013 · Birefringence of polymers should be controlled for some photonic devices.IntroductionA polymer molecular chain has a polarizability anisotropy originated … soin tcode in sapWebJun 1, 2000 · By using highly birefringent polymers in thin-film, multilayer mirrors, however, the 3M group appears to have exceeded Brewster's fundamental and two-centuries-old optical limitation. For example, they can now build a mirror that works just the opposite: reflectivity of p -polarized light could increase from zero at normal incidence to … soin technispaWebRelationship between segmental anisotropy in polarizability and stationary ultrasonically induced birefringence in polymer solutions. Journal of Molecular Liquids 2004 , 110 (1-3) , 57-62. soin tachyonsWebBirefringence is an optical property showing mechanical stress and anisotropy in transparent plastic parts. During processing the polymer experiences a lot of stress which could orient the molecular chains in undesirable manner inducing stress. slug and lettuce brunch liverpool