The influence of three different salts (KCl, 0.0002 M; CaCl2, 0.0001 M
, NaCl, 0.0002 M) on the slip velocity of 0.3% xanthan solutions, arou
nd the corresponding order-disorder conformational transition temperat
ure, was investigated with a glass capillary rheometer. An enhancement
of the slip velocity was observed very near the transition for the th
ree salts studied. This result is similar to the one reported by us, u
sing two different xanthan samples in the absence of salt. The behavio
r of the power-law parameters of the slip velocity was similar to the
one obtained with xanthan without salt around the transition temperatu
re. Slip was determined with the Mooney method, showing good results a
nd only small discrepancies at higher temperatures (T > 34 degrees C).