YANG Ge, CHEN Jian, QU YinBo, LUN ShiYi. STUDIES ON RHEOLOGICAL CHARACTERISTICS OF γ-POLY(GLUTAMIC ACID) PRODUCED BY BACTERIA[J]. Acta Polymerica Sinica, 2002,(3):345-348.
YANG Ge, CHEN Jian, QU YinBo, LUN ShiYi. STUDIES ON RHEOLOGICAL CHARACTERISTICS OF γ-POLY(GLUTAMIC ACID) PRODUCED BY BACTERIA[J]. Acta Polymerica Sinica, 2002,(3):345-348.DOI:
The rheological characteristics γ-poly(glutamic acid) (γ-PGA) solution have been investigated. The solution is a typical non-Newtonian shear-thinning fluid with a characteristic n-parameter lower than l.With temperature raised
the viscosity of γ-PGA solution shows the trend of decreasing.Over the angular frequency(ω) range 0.01~100 rad·s-1
the storage modulus (G′) of 5% (W/V) γ-PGA gels is much higher than its loss modulus (G″) and loss dependent on frequency which showed that γ-PGA has fine elasticity.1% is close to the threshold concentration needed for gelation.γ-PGA is dispersible in cold water to form weak gel.Continuous heating at high temperature treatment changed the network of γ-PGA gel.Similar results are observed for γ-PGA gels prepared under pH 4 and 12.Addition of 1%~10% NaCl
7%KCl
MgSO4
ZnSO4 and CaCl2 decrease the G′ of 2% γ-PGA gel at low frequency and increased G″ over the frequency rang 0.01~100 rad·s-1 which indicated that the formation of elastic network is hindered. However
addition of 1.7% PbNO3 of 1.7% AgNO3 makes total loss of viscoelasticity of the 2% γ-PGA system.