Modern Polymer Spect..

3.20 References 201
very important, since having a strong dipole perpendicular to the chain axis shows
remarkable pyro and piezoelectric properties widely used in modern technology.
According to Dwey-Aharon when the conformationally disordered material existing
in form I1 is placed in a strong electric field (poling) conformational twistons are
generated which propagate and yield form I. The spectroscopy of polyvynilidene
fluoride and the search for twistons has been treated in [171].
Finally, the concept of twiston has been again introduced in a spectroscopic work
to account for the set of peculiar experimental data collected in the study of the
phase transition in ethylene-tetrafluoroethylene alternating copolymers [ 1721.
Acknowledgments
The contributions to knowledge presented in this chapter are the result of an
enthusiastic collaboration of many researchers and students who worked in our
group at the Politecnico of Milano. Our warmest thanks are extended to Dr. M.
Gussoni, who laid the background for the development of this science.
3.20 References
[l] H. H. Nielsen, Ha?idbzrclz der Plzvsik, Springer, Berlin, Vol. 37/1, 1959.
[2] G. Herzberg, Infrared and Ranian Spectra of’ Polyatonzic Molecules, Van Nostrand, Princeton,
USA, 1963.
[3] E. B. Wilson, J. C. Decius and P. C. Cross, Moleculur I/ibrutioiis, McGraw Hill, New York,
1955; V. Volkenstein, M. A. Eliashevich and B. Stepanov, Kolebuni.vu Molecul 11, Moscow,
1949; S. Califano, Vibrational Stutes, Wiley, New York, USA, 1976.
[4] For a general discussion see: W. Person and G. Zerbi (Eds.), Vibrotional61teizsities in Infrared
and Ranm Spectroscopy, Elsevier, Amsterdam, The Netherlands, 1984; L. A. Gribov, Intensity
Theory for IIfrared Spectra of Polyatoniic Molecarles, Consulting Bureau, New York,
USA, 1964.
[5] M. Gussoni in Aduances in hfiared and Ru~nan Spectroscopy, (Eds. R. J. H. Clark and R. H.
Hester) Heyden, London, England, 1979, vol. 6 p. 96.
[6] M. Gussoni, C. Castiglioni and G. Zerbi, J. Mol. Strzrct, 1989 198, 475 M. Gussoni, C.
Castiglioni, M. N. Ramos, M. Rui and G. Zerbi, J. Mol. Strirct. 1990 224, 225 C. Decius, J.
Mol. Spectry, 57, 384 1975; A. J. Van Straten and W. Smit, .I Mol. Spectry., 1976 62, 297 M.
Gussoni, C. Castiglioni and G. Zerbi, J. Phys. Clienz. 1984 88, 600.
[7] S. Trevino and H. Boutin, J. Macronzol. Sci., 1967 Al, 723.
[8] E. Curtis, Thesis, University of Minnesota, 1958.
[9] J. H. Schachtschneider and R. G. Snyder, Spectrocki/n. Acro, 1963 19, 17.
[lo] The most known set of original computing programs which has later originated many other
programs for dynamical and force constant calculations is that written by J. H. Schachtschneider,
Shell Rep. 57/65.
[ 111 See, for instance, J. L. Duncan, Force Curisfunt Calcirlcrtions ik hfokecirles, Specialist Report,
Chemical Society, London, 1975, vol. 23, p. 104: G, Fogardsi and P. Pulay, in I’ihr.trtiorm/
Spectru cind Strircfure, (Ed. J. R. Durig) Elsevier, Amsterdam, 1985, Vol. 14, p. 125.