Conformation and Dynamics of Polyelectrolytes in Non-Aqueous Solutions

1997 Fiscal Year Final Research Report Summary

• Project/Area Number: 08455451
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 高分子構造・物性(含繊維)
• Research Institution: Nagoya University
• Principal Investigator: NODA Ichiro Nagoya University, Applied Chemistry, Professor, 工学研究科, 教授 (30023055)
• Co-Investigator(Kenkyū-buntansha): TAKAHASHI Yoshiaki Nagoya University, Applied Chemistry, Assistant Professor, 工学研究科, 助手 (40188066) ; MUROGA Yoshio Nagoya University, Applied Chemistry, Associate Professor, 工学研究科, 講師 (00115643)
• Project Period (FY): 1996 – 1997
• Keywords: Polyelectrolyte / Viscoelastic Properties / Dielectric Constant / Non-Aqueous Solution / Intrinsic Viscosity / Poly (sodium stirene sulfonate) / Formamide / Ethylene Glycohol

Research Abstract

In this research project the effects of dielectric constant on expansion, intermolecular interactions and viscoelastic properties of polyelectrolytes were studied. The main conclusions obtained here are the followings.
1.Expansion and Interactions of Polyelectrolytes in Non-Aqueous Dilute Solutions
Polyelectrolytes used here were sodium poly (stirene sulfonate) s (NaPSS) with different molecular weights, prepared by sulfonation of polystirenes with narrow molecular weight distributions according to Vink's method. The degrees of sulfonation of the samples are nearly 100%.
Measurments of light scattering and viscosity were carried out for the NaPSS samples in dilute solutions of formamide, of which the dielectric constant (epsilon=111) is higher than water (epsilon=80.1), in the presence of added salt (NaCl). It was found that the radius of gyration and intrinsic viscosity in formamide solutions are larger than in aqueous solutions, though their molecular weight dependencies in the former a re similar to those in the latter, and the second virial coefficients in the former are also larger than in the latter. This means that the magnitude of excluded volume effects in formamide solutions is larger than in aqueous solutions.
2.Viscoelastic Properties of Polyelectrolytes in Non-Aqueous Solutions
Zero-shear viscosity eta^0 and steady state compliance J_e of the NaPSS samples were measuerd in aqueous and non-aqueous solutions in the absence and presence of added salts (NaCl) by oscillatory, creep and creep recovery experiments. Non-aqueous solvents used here were formamide and ethylene glycohol (epsilon=38), of which the dielectric constants are higher and lower than that of water, respectively. It was found that eta^0 and J_e in formamide solutions have almost the same molecular weight and polymer concentration dependencies as in aqueous solutions in dilute, semidilute and concentrated regions, while in ethylene glycohol solutions they have almost the same dependencies as for neutral polymers in good solvents in the three concentration regions.