Optical Properties of Nematic Poly-γ-Benzyl-L-Glutamate

  • Donald B. DuPré
  • James R. Hammersmith

Abstract

Poly-γ-benzyl-L-glutamate (PBLG) in certain solvents adopts an α-helical conformation and thus geometrically resembles a long, rigid rod with side chains containing benzyl radicals extending latterally outwards along the rod axis. As the refractive indices parallel and perpendicular to the helical axis are different, a-lignment of the macromolecule results in optical birefringence, The effect is dramatically seen by simply allowing a PBLG solution to flow between crossed polars. The rod shaped macromolecules tend to conform with hydrodynamic flow lines, producing a birefringent solution of remarkable color (streaming birefringence). The PBLG molecule itself has a positive dielectric and diamagnetic aniso-tropy, with the components of the dielectric and magnetic susceptibility tensor parallel to the long molecular axis larger than those perpendicular. In the presence of an electric or magnetic field individual PBLG molecules will also tend to align themselves, in this case such that their long axes are parallel to the direction of imposed field.

Keywords

Vortex Convection Petroleum Chloroform Polypeptide 

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References

  1. 1.
    E. T. Samulski and A. V. Tobolsky, Macromolecules 1, 555 (1968).CrossRefGoogle Scholar
  2. 2.
    S. Sobajima, J. Phys. Soc. Japan, 23, 1070 (1967).CrossRefGoogle Scholar
  3. 3.
    M. Panar and W. D. Phillips, J. Amer. Chem. Soc, 90, 3880 (1968).CrossRefGoogle Scholar
  4. 4.
    R. D. Orwoll and R. L. Void, J. Amer. Chem. Soc, 93, 5335 (1971).CrossRefGoogle Scholar
  5. 5.
    E. Iizuka, Biochem. Biophys. Acta 243, 1 (1971).Google Scholar
  6. 6.
    E. Iizuka and Y. Go, J. Phys. Soc. Japan, 31, 1205 (1971).CrossRefGoogle Scholar
  7. 7.
    W. J. Toth and A. V. Tobolsky, Polymer Letters 8, 531 (1970).CrossRefGoogle Scholar
  8. 8.
    C. Robinson, Trans. Faraday Soc 52 571 (1956).CrossRefGoogle Scholar
  9. 9.
    R. Williams, Phys. Rev. Letters 21., 342 (1968).Google Scholar
  10. 10.
    R. Williams, J. Chem. Phys. 50, 1324 (1969).CrossRefGoogle Scholar
  11. 11.
    C. Robinson, Mol. Crystals Liq. Crystals 1, 467 (1966).CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1974

Authors and Affiliations

  • Donald B. DuPré
    • 1
  • James R. Hammersmith
    • 1
  1. 1.Department of ChemistryUniversity of LouisvilleLouisvilleUSA

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