聚电解质溶液特性黏数确定方法的再探讨

Further Discussion on Method to Determine the Intrinsic Viscosity of Polyelectrolyte Solution

Wolf提出用普适特性黏数{η}的外推值,或者用高分子溶液相对黏度的对数值lnηr对浓度C作图的起始斜率,可以更加有效地确定聚电解质溶液的特性黏数。文中的研究结果表明,当高分子溶液浓度趋近于零时,普适特性黏数{η}、表观特性黏数[η]app和比浓黏度ηsp/C的值趋于一致;不仅如此,聚电解质溶液黏度的测定结果表明,当浓度C趋近于零时,{η}、[η]app和ηsp/C三者随浓度C的变化趋势也完全一致,说明用{η}或者[η]app的外推值与用Huggins比浓黏度ηsp/C对浓度C作图的外推值来确定聚电解质溶液特性黏数从本质上来说是完全一致的。

According to the method presented by Wolf,the intrinsic viscosity of polyelectrolyte can be obtained either by extrapolating the generalized intrinsic viscosity {η} towards zero concentration C or by the initial slope of the dependence of the logarithm of the relative viscosity lnηr on polymer concentration C.Our research indicates that the value of the generalized intrinsic viscosity {η},the apparent intrinsic viscosity [η]app and the reduced viscosity ηsp/C become the same as extrapolating concentration C to zero.Furthermore,the viscosity measurement indicates that the dependence of {η},[η]app and ηsp/C with concentration C is just the same in extremely diluted polyelectrolyte solutions.This suggests that the method to determine the intrinsic viscosity of polyelectrolyte by extrapolating the generalized intrinsic viscosity {η} towards zero concentration C is essentially just the same as extrapolating ηsp/C towards zero concentration C in the Huggins ηsp/C versus C plot which is traditionally used.