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Journal of Physical Studies 9(1), 45–51 (2005)
DOI: https://doi.org/10.30970/jps.09.45 INELASTIC NEUTRON SCATTERING STUDY ON EG AND PEGS AS A FUNCTION OF THE DEGREE OF POLYMERIZATIONS. Magazù, G. Maisano, F. Migliardo Dipartimento di Fisica and INFM, Università di Messina, PO Box 55, I-98166 Messina, Italy |
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The present paper concerns with Inelastic Neutron Scattering (INS) results on Ethylene Glycol (EG) and PolyEthylene Glycols (PEGs) at different degree of polymerization. Significant spectral features of these systems are discussed in comparison with Raman spectroscopy findings. The results reveal a peculiar dependence on the degree of polymerization of the frequencies of the disordered longitudinal acoustic mode (D-LAM), which can account for the different bioprotectant effectiveness of PEGs at ambient and at very low temperature. The D-LAM behaviour as a function of the degree of polymerization as obtained by INS at low temperature is opposite to that observed by Raman spectroscopy at high temperature. These intriguing results are discussed in terms of inter and intra-molecular interactions within the framework of current theories.
PACS number(s): 61.12.Ex; 61.25.Hq; 63.50.Qx