Transmission guest-host effect

White and Taylor have described a new device that combines both the guest-host effect and the cholesteric-to-nematic transition. The pleochroic dye is added to a cholesteric material and the cell transmission changes when the cholesteric undergoes the cholesteric-to-nematic transition. Because of the rotational symmetry of the long axes of the dye molecules about the cholesteric helical axes, contrast ratios of greater than 4 to 1 were obtained without the use of a polarizer. 

The built of realistic clusters or host-guest nanocomposites require effective experimental tools such as transmission electron microscopy (TEM) images, which illustrate the involved crystalline order both in the core and in the outermost particle siufaces. Second relevant information deals with the experimental vibrational spectra of SiC. The validity of theoretical construction of smaU-size dusters and evaluation of their physical properties should follow the experimental behavior. Also, IR and Raman experiments were performed on the SiC nanopartides and will serve as reference for testing the relevance of the carried out numerical simulations performed. Representative experimental data, required for the initiation of theoretical model, are hereafter reported and consist in morphology and vibrational features of SiC nanopartides. 

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