Abstract

We present investigations of the structures and properties of the complex formed by a strong polyanion: poly-(sodium 4-styrene sulfonate) (PSSNa) and weak polycation: poly-L-ornithine (PLO) by combining dynamic light scattering (DLS), ultra-small-angle light scattering (USALS), turbidimetry, and zetametry techniques. The mixtures of polyelectrolytes were controlled in several ways: by the change of pH, modifying the mass ratio, the temperature, and adding divalent salt. Under these conditions, the hydrodynamic radius R_H, the viscosity η, the radius of gyration R_g, and the fractal dimension D_f were determined. The maximum charge difference of biopolymers stock dispersion was displayed at pH 3.3 and at mass ratio equal to 1. The screen of electrostatic interaction shows a high contribution of hydrophobic interaction at large salt concentration to form the coacervates and the effect of temperature and ionic strength highlighted the strongly hydrophobic character of mixture. The results allowed us to conclude that the complexation was controlled by electrostatic interactions between opposites charges.

摘要

我们通过结合动态光散射 (DLS) 研究了由强聚阴离子：聚-(4-苯乙烯磺酸钠) (PSSNa) 和弱聚阳离子：聚-L-鸟氨酸 (PLO) 形成的复合物的结构和性质，超小角光散射 (USALS)、比浊法和 zetametry 技术。聚电解质的混合物可以通过多种方式控制：通过改变 pH 值、改变质量比、温度和添加二价盐。在这些条件下，流体动力学半径R _H、粘度η、回转半径R _g和分形维数 D _f被确定。生物聚合物浆料分散体的最大电荷差显示在 pH 3.3 和质量比等于 1 时。静电相互作用的筛选显示，在大盐浓度下疏水相互作用对形成凝聚层的贡献很大，温度和离子强度的影响突出混合物的强疏水性。结果使我们得出结论，络合是由相反电荷之间的静电相互作用控制的。