Dielectric dispersion of polyglutamic acid solution

Abstract

AbstractThe dielectric dispersion of polyglutamic acid (PGA) was studied in the pH range of 4–9.8. Three different dispersion curves were obtained. Above pH 6.0, where PGA has a random coil configuration, the dielectric dispersion is characterized by a large dielectric increment (ca. 450) and a relaxation time of 10–12.7 × 10−6 sec. Between pH 6.0 and 5.0, where PGA is in a transitional state with small viscosity, a dispersion curve with very small dielectric increment and also small relaxation time was observed. Below pH 5.0, where PGA has a helical configuration, the dispersion is characterized by a relaxation time of 10–12 × 10−6 sec. and a dielectric increment of about 120. The dipole moment of coil and helical forms of PGA were calculated by using Allgen's equation, and qualitative discussions of these dielectric properties are presented.