Conformation of the xanthan molecule

5 fim is, in fact, the hydrodynamic length of xanthan in solution and not the molecular length, which is estimated to be 2-10 jum (Holzwarth and Prestridge, 1977) in fact they calculated an extended rod length of S.l fim for their xanthan. 

At present, the consensus appears to be that native xanthan virtually always has a double helix structure and that this is retained in most injection and reservoir brines over all of the temperature range for which xanthan is stable ( 85°C). 

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G. Muller, J. Lecourtier, G. Chauveteau, and C. Allain, Conformation of the xanthan molecule in an ordered structure, Makromol. Chem.. Rap. Commun. 5 203 (1984)... 

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