Faithin Omaha eBook Collection

Download or read book Light Scattering from Macromolecular Systems - Molecular Crystals and Polymers written by and published by . This book was released on 1981 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research objectives of this grant are to (1) characterize phase transitions theoretically and experimentally in molecular crystal systems, (2) use the above understanding gained by light scattering studies and theoretical interpretation to apply to the more complex system of lyotropic liquid crystals, and (3) knowledge gained on the model systems of increasing complexity is then applied to polymer liquid crystals and solid polymers as observed by laser light scattering techniques. Objective one has been definitely achieved as can be seen from the number of papers written in the last few years. Systems to have been experimentally and theoretically discussed are: trioxane, triazine, benzil, and chloranil. Others still to be investigated are: biphenyl, urea, thiourea, and hexamethyl benzene. Studies of lyotropic liquid crystals (sodium decyl sulfate, sodium sulfate, decanol, water) have been progressed to the point at which we will be reporting this data shortly. The major findings are: a number of phase transitions occur between 20 and 60 C; these transitions evidence strong critical behavior and long correlation times for fluctuations; and liquid crystals can be studied by light scattering in a unique and meaningful manner. Finally, some polymer studies were started which will be continued into the coming contract period. Spectra of solid powders, ribbons, and liquid crystals of PBT and solid PBO were obtained.