海藻酸钠溶液的动静态光散射和扩散波谱研究

Characterizations of the sodium alginate solutions via DLS/SLS and DWS techniques

海藻因其优异特性,被广泛用于食品、生物医学等领域。海藻水溶液的性质很大程度受到溶液环境的影响。本文基于动静态同步光散射和扩散波谱技术分别研究pH和盐对于海藻酸钠稀溶液和浓溶液形态的影响,从溶液构象和网络结构多个尺度深入探讨宏观性能差异背后的作用机制。研究发现,溶液pH和盐的变化带来的海藻的电离平衡的改变,使得氢键和静电作用权重发生变化,这是不同溶液环境下粘度差异、凝胶化现象的根本原因。

Sodium alginate is widely used in food,biomedicine and other fields because of its excellent characteristics.The physicochemical properties of the sodium alginate solutions are greatly affected by the ambient conditions.Based on the dynamic and static light scattering technique and the diffusing-wave spectroscopy method,in this paper,the influences of pH and salt on the morphology of sodium alginate aggregates in dilute and concentrated solution respectively were studied,and the mechanism behind the macroscopic performance variation was explored by the point of views of the solute molecule conformation and its network structure,which covers multiple scales,in solutions.It is elucidated that the trade-off between the screening effect of salt for double-layer interactions and hydrogen bond in ionization process due to pH variation regulates the viscosity of solutions and thereby gelation process.