Viscolastic relaxations in solutions of poly(glutamic acid) and gelatin at ultrasonic frequencies

✍ Scribed by Yasaku Wada; Hiroyuki Sasabe; Makoto Tomono

• Publisher: Wiley (John Wiley & Sons)
• Year: 1967
• Tongue: English
• Weight: 456 KB
• Volume: 5
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1967.360051003

✦ Synopsis

Complex shear viscosity q* = 7'iq" of poly(L-glutamic acid) solution was measwed by the torsional crystal method at 50 kc./sec. as a function of pH. A sharp peak was found at the midpoint of the helix-coil transition region in both q' and 7". The relaxation time is calculated from 7' and 7" assuming a single relaxation process and the peak value at the midpoint of transition is estimated p t 10" sec. Such behavior agrees well with the prediction from the theory of Schwarx. The atteniiation of longitudinal sound waves at 3 Mc./sec. was measured as a funct>ion of pH for solutions of poly(g1ittamic acid), glutamic acid, and gelatin. A small attenitation peak was observed for the three solutions, the peak height being almost, the same for them. The peak is interpreted in terms of the dissociation reaction of side chains.