Polarized optical microscope

Isothermal crystallization was carried out at some range of degree of supercooling (AT = 3.3-14 K). AT was defined by AT = T - Tc, where Tj is the equilibrium melting temperature and Tc is the crystallization temperature. T s was estimated by applying the Gibbs-Thomson equation. It was confirmed that the crystals were isolated from each other by means of a polarizing optical microscope (POM). 

Isothermal crystallization was observed by means of SAXS and a polarizing optical microscope (POM, OLYMPUS, BX or BHS-751-P). The SAXS experiment was carried out using synchrotron radiation on the beam line BL40B2 of SPringS (SP8) at JASRI in Harima and at the BL-10C small angle installation of the Photon Factory (PF) at KEK in Tsukuba. 

It is interesting to study the compatibility of PE-g-PS copolymer in HDPE and PS blends. Polarized optical microscope and the SEM were used to examined the surfaces and bulk morphologies, respectively. Two blends comprised of overall 50/50 weight ratio of PE and PS, one is a simple mixture of 50/50 between HDPE and PS and the other is 45/45/10 weight ratio of HDPE, PS, and PE-g-PS with 50 mole % PS. 

Figure 25.3 Polarizing optical microscopic images and schematic illustrations of the oriented and self-assembled structures of 10b in the hexagonal columnar state (a) Before shearing (b) after shearing the material along the direction perpendicular to the Au electrodes. Directions of A analyzer P polarizer S shearing. (Reproduced with permission from J. Am. Chem. Soc., 126, 994-995 (2004). Copyright 2004 American Chemical Society)...

FIGURE 8-1 Nylon spherulites observed under a polarized optical microscope. 

Fig. 4. Rubrene thin film on mica substrate under polarized optical microscope.

Under the polarized optical microscope, the liquid crystal films show colorful patterns, i.e., the optical textures. Each liquid crystal phase shows its typical texture which provides the means to identify the phase of the liquid crystals. The typical textures are the Schlieren, threadlike, homeotropic, homogeneous, marble, finger-print, focal-conic, Dupin cyclide, fan-shape, sanded, mosaic, and so on. They are the integrations of many typical defects mentioned above. Demus Richter (1978) were the first to review... 

The X-ray diffraction of polymeric liquid crystal systems and their low mass counterparts are the same in principle, but the diffraction results for the polymers are often less ideal and more difficult to interpret. In practice the oriented specimens are often preferred over the unoriented samples for an unambiguous determination. X-ray diffraction is nearly always used together with texture observations using a polarizing optical microscope. Miscibility tests are also used in some cases for confirmation. For smectic phases with higher translational and orientational orders, X-ray diffraction is the most useful (if not the only) technique for unmistakable characterization. A few examples are cited below. The details of each characterization of the various polymeric smectic phases were described by individual authors. 

Polarized optical microscope Small-angle X-ray scattering Syndiotactic polypropylene Loss tangent... 

In a polarizing optical microscope with crossed polarizer and analyzer, a transparent spherical isotropic sample looks like a bright object on the dark... 

The synthesized GNPs have been dispersed into a variety of host LCs and comprehensively characterized by multiple techniques. For example, the transition temperatures of the GNPs coated with mesogen 1 (Scheme 4.1) in 4 -n-octyl-4-cyano-biphenyl (8CB), which exhibits nematic and smectic A phases, were determined as a function of concentration by DSC, as shown in Table 4.1 [46]. For a 5 wt% mixture of 1 coated GNPs in 8CB, by using polarized optical microscope... 

Fig. 4.15 (Top) Images of 0.5 wt% P GNR (22) in LCP thin films under crossed polarized optical microscope. Scale bar 100 pm. Shearing direction was about 45° to the polarizer [107]. (Bottom) TEM images of 22 (n = 8) coated GNRs in LCP. a Before UV irradiation, b After UV irradiation, c After shearing, c was from scanning TEM. Copyright from ACS 2013...

Figure 5.19 (a) Schematic of a lamella, (b) schonatic of a spherulite, and (c) a polarized optical microscope... 

Figure 7.6 Polarized optical microscope image of the SMPF...

The healed crack interface was also investigated using a polarized optical microscope. In Figure 7.40, the narrowed cracks are filled in with the healing agent (i.e., thermoplastic). 

From DSC thermogram, optical anisotropy under polarizing optical microscope (p.o.m.) and wide-angle X-ray diffraction (w.a.x.d.) data it can be deduced that the endothermic peak at 77 °C is due to the mesomorphic-isotropic phase transition. The enthalpy of phase transition is 20.35 J/g. Hence, according to Brandon and Marmur (1996), the structure of PAC8 below 77 °C is ordered in smectic crystalline, which can be classified as smectic B (Sb) type. 

FIGURE 3.1 Chiral nematic LC induced by the addition of chiral dopant into nematic LC. Schlieren texture ( left) and fingerprint texture ( right) are observed for nematic and chiral nematic LCs, respectively, in polarized optical microscope. 

---