Circular birefringence of banded spherulites
WebApr 8, 2014 · Circular Birefringence of Banded Spherulites Crystal optical properties of banded spherulites of 21 different compounds molecular crystals, polymers, and … WebApr 28, 2004 · The lamellae exhibit complicated growth behaviors: twisting, bending, backward growth, and branching. The lamellae continuously twist to show alternating edge-on and flat-on views along the radii of the spherulites. Giant screw dislocations bring forth to the birth of new lamellae.
Circular birefringence of banded spherulites
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WebThe circular birefringence is shown to be a consequence of misoriented, overlapping anisotropic lamellae, a kind of optical activity associated with the mesoscale … WebWe report stress birefringence measurements for small (up to 150 mm x 150 mm) samples such as Si slabs, wafers and small ingot segments. Measured stress birefringence in an Si ingot segment...
WebOct 29, 2015 · Neat poly (1,6-hexamethylene adipate) (PHA) is one polyester that never forms ring banded spherulite when crystallized at any crystallization temperatures ( Tc s). However, PHA spherulites readily transform from negative-type at low Tc s (32–38 °C) to positive-type at high Tc s (46–48 °C). WebCircular Birefringence of Banded Spherulites Xiaoyan Cui,†Alexander G. Shtukenberg,*, †John Freudenthal,†Shane Nichols,†Bart Kahr*† †Department of Chemistry, New York …
WebJan 31, 2024 · Crystal assembly by crystallization and self-aggregation into periodicity, viewed as circular ring bands in optical birefringence patterns, in the family of aliphatic polyesters is surveyed. The periodic packing in all polyesters shares similarity of grating architectures in interiors and banding on top surfaces. WebNov 7, 2024 · Substrates partially covered with F10H16 contain incomplete ring-banded spherulites and smaller objects in which lamellae and circular nanodomains co-exist. …
WebSep 23, 2024 · A novel 3D growth mechanism of ring-banded spherulite is proposed. 2. Experimental 2.1. Materials and Preparation PBA and PEO were dissolved into chloroform and made into a 2 wt.% polymer solution. PBA was purchased from Aldrich Chemical Company, Inc. (St. Louis, MO, USA), with M w = 12,000 g/mol, T g = −66.2 °C, and T m …
WebMar 13, 2014 · Circular birefringence (CB) has recently been used to interrogate banded spherulites. Cui et al. [45] observe that CB oscillates along the radius, 90 • out of phase … small or med hoodieWebMay 1, 2016 · The essential component of a spherulite is fibrillar crystals that grow in predominantly radial directions and branch irregularly. We review the growth, branching … small or handheld carpet cleanerWebMar 13, 2014 · Circular Birefringence of Banded Spherulites J. Am. Chem. Soc. March 13, 2014 Other authors. See publication. Twisted … highlight keywords in textWebAug 12, 2011 · The circular birefringence of polycrystalline polymers is invariably obscured by strong linear birefringence. To parse the two mechanisms of light retardation, polycrystalline spherulites of... highlight keyboard wordWebOct 1, 2015 · There are many other types of “bands” in crystallized spherulites – including “radial stripes” with alternate birefringence colors as bands – periodic bands – because … small opus patternWebDec 7, 1999 · We discuss and evaluate methods for determining handedness of twisting, particularly in tightly banded spherulites, and illustrate them by application to poly(3 … highlight keystrokeWebSep 7, 2011 · The circular birefringence of polycrystalline polymers is invariably obscured by strong linear birefringence. To parse the two mechanisms of light retardation, polycrystalline spherulites of polylactide enantiomers were … small or little in spanish