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Vacuum ultraviolet circular dichroism of gellan-family polymer films from water and dimethyl sulfoxide

✍ Scribed by Edward R. Arndt; Eugene S. Stevens


Book ID
102993027
Publisher
Elsevier Science
Year
1996
Tongue
English
Weight
637 KB
Volume
280
Category
Article
ISSN
0008-6215

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✦ Synopsis


The denaturing effect of dimethyl sulfoxide (Me2SO) on the conformation of the gellan-welan-rhamsan family of microbial polysaccharides is directly demonstrated by circular dichroism (CD). The three polysaccharides display strikingly similar CD spectra (140-210 nm) for films cast from Me2SO. The disrupting effect of Me2SO on gellan and welan conformations has previously been reported by others on the basis of light-scattering and viscosity studies. Films cast from aqueous solutions at room temperature show more-intense CD bands, both at 182 nm, as is also observed for aqueous solutions, and in the 150-175 nm region. These features correspond to the ordered helical chains found by X-ray diffraction studies of similarly prepared films.