Microscopy polarization

In summary, polarizing microscopy provides a vast amoimt of information about the composition and three-dimensiraial structure of a variety of samples. The technique can reveal information about thermal history and the stresses and strains 

Other cases, polymers can undergo lyotropic or thermotropic liquid crystalline phase transitions, which can often be observed and recorded in a polarized light microscope. 

---

The solid-liquid transition temperatures of ionic liquids can (ideally) be below ambient and as low as -100 °C. The most efficient method for measuring the transition temperatures is differential scanning calorimetry (DSC). Other methods that have been used include cold-stage polarizing microscopy, NMR, and X-ray scattering. 

Characterization439 Inherent viscosity before and after solid-sate polymerization is 0.46 and 3.20 dL/g, respectively (0.5 g/dL in pentafluorophenol at 25°C). DSC Tg = 135°C, Tm = 317°C. A copolyester of similar composition440 exhibited a liquid crystalline behavior with crystal-nematic and nematic-isotropic transition temperatures at 307 and 410°C, respectively (measured by DSC and hot-stage polarizing microscopy). The high-resolution solid-state 13C NMR study of a copolyester with a composition corresponding to z2/zi = 1-35 has been reported.441... 

The compensation birefringence measurement is very easily coupled to optical microscopy in the transmission and reflection modes, thus allowing characterizing orientation with a spatial resolution of a few hundreds of nanometers [14]. Polarizing microscopes are widely available and are often used for birefringence studies even if spatial resolution is not required. Objectives specifically designed for cross-polarized microscopy are necessary to avoid artifacts. 

Rizzo, M. A. and Piston, D. W. (2005). High-contrast imaging of fluorescent protein FRET by fluorescence polarization microscopy. Biophys. J. 88, L14—6. 

Ellis, I.O., Bell, J., and Bancroft, J.D. (1988) An investigation of optimal gold particle size for immuno-histological immunogold and immunogold-silver staining to be viewed by polarized incident light (EPI polarization) microscopy./. Histochem. Cytochem. 36, 121-124. 

Samples for infra-red absorption measurement were introduced between two rubbed nylon coated calcium fluoride substrates spaced 10 pm apart. To insure proper parallel alignment, samples were cooled at 0.02° C/minute from the isotropic to the Smectic C phase. The alignment was then checked using polarizing microscopy. Polarized IR spectra (32 scans per spectrum) were obtained using an FTIR spectrometer (IFS-66 Bruker, Pillerica, MA) equipped with a wire grid polarizer at a resolution of 2 cm"1. 

Polarization microscopy waves, useful for examining biological material which possesses limited inherent direct contrast Most useful for highly X-ray Detection, localization, and quantitation of... 

Solid films of our block copolymers and their surface behavior have been examined using a variety of techniques. Block copolymers composed of incompatible polymer blocks are known for mesophase formation as a consequence of the microphase separation of the chains. Our fluorinated block copolymers form a microphase-separated structure with a high degree of order. This can easily be visualized by polarization microscopy and SAXS. 

Piston DW, Rizzo MA (2008) FRET by fluorescence polarization microscopy. Methods Cell Biol 85 415-30... 

Modification of the PA/AA/NPG diol with salicylic and with m-hydroxybenzoic acids apparently did not proceed to completion. The products appeared amorphous by polarizing microscopy. 

Morphology of oligomers. PHBA-containing oligomers were studied by DSC and by polarizing microscopy with the results indicated in Table 2. The polarizing micrograph of the 40/60 PHBA/diol ratio LC polyol (Fig. 5) is typical. 

Table 2. Differential Scanning Calorimetry and Polarizing Microscopy of Polyols...

The 30/70, 40/50, and 50/50 PHBA/diol oligomers are clearly heterogeneous. The fact that they form stable dispersions in MIBK, their appearance, and polarizing microscopy indicate that they are... 

For crystalline polymer systems, transition from the crystalline structure to a mesophase structure occurs, whereas for amorphous polymer systems, the mesophase occurs after the Tg has occurred. Some polymer LC systems form several mesophases. Mesophases can be detected using DSC, x-ray diffraction, and polarizing microscopy. 

Oron, D., Tal, E., and Silberberg, Y. 2003. Depth-resolved multiphoton polarization microscopy by third-harmonic generation. Opt. Lett. 28 2315-17. 

LB films prepared from an azabenzene-containing surfactant donor-TCNQ acceptor and transferred to solid substrates Absorption spectra, polarized microscopy, and conductivity measurements... 

The textures in homeotropic lamellar phases of lecithin are studied in lecithin-water phases by polarizing microscopy and in dried phases by electron microscopy. In the former, we observe the La phase (the chains are liquid, the polar heads disordered)—the texture displays classical FriedeVs oily streaks, which we interpret as clusters of parallel dislocations whose core is split in two disclinations of opposite sign, with a transversal instability of the confocal domain type. In the latter case, the nature of the lamellar phase is less understood. However, the elementary defects (negative staining) are quenched from the La phase they are dislocations or Grandjean terraces, where the same transversal instability can occur. We also observed dislocations with an extended core these defects seem typical of the phase in the electron microscope. 

---