Light microscopy differential interference contrast

Figure 7.22 Microstructure of acidified mixed emulsions (20 vol% oil, 0.5 wt% sodium caseinate) containing different concentrations of dextran sulfate (DS). Samples were prepared at pH = 6 in 20 mM imidazole buffer and acidified to pH = 2 by addition of HCl. Emulsions were diluted 1 10 in 20 mM imidazole buffer before visualization by differential interference contrast microscopy (A) no added DS (B) 0.1 wt% DS (C) 0.5 wt% DS (D) 1 wt% DS. Particle-size distributions of the diluted emulsions determined by light-scattering (Mastersizer) are superimposed on the micrographs, with horizontal axial labels indicating the particle diameter (in pm). Reproduced with permission from Jourdain et al. (2008).

Nomarski microscopy is an examination mode using differential interference contrast (DIC). The images that DIC produces are deceptively three-dimensional with apparent shadows and a relief-like appearance. Nomarski microscopy also uses polarized light with the polarizer and the analyzer arranged as in the polarized light mode. In addition, double quartz prisms ( Wollaston prisms or DIC prisms) are used to split polarized light and generate a phase difference. 

CD Circular dichroism Die Differential interference contrast DLS Dynamic light scattering FTIR Fourier-transform infrared LSCM Laser scanning confocal microscopy LCST Lower critical solution temperature Me Methyl... 

Differential interference contrast (DIG) microscopy, which provides a better contrast than the phase-contrast method. This utilizes a phase difference to improve contrast, but the separation and recombination of a light beam into two beams is accomphshed by prisms. 

Then, microscopic examinations follow optical research microscopes allow to determine the number, thickness, and color sequence of layers in paint fragments, and to recognize the textures as well as fundamental features of pigment and extender mixtures. Bright field and dark field illuminations, polarized light microscopy (incident and transmitted), particularly the differential interference contrast (DIC) procedure, and fluorescence microscopy are necessary for paint examinations (see Figure 3(A)-3(E)). 

The common contrast modes include polarized light, phase contrast, differential interference contrast, and Hoffman modulation contrast [5]. Depending on the nature of the polymer, such as refraction index, sample thickness, and optical anisotropies in the materials, different modes of transmission optical microscopy can be employed by mounting special accessories in a classic optical microscope to overcome different problems. For example, a polarizer and analyzer can be mounted before and after the sample to construct a polarized light microscope, commonly used for semicrystalline polymers a phase plate and phase ring can be added to construct a phase contrast optical microscopy, which is common for studying a noncrystafline multiphase polymer system. 

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