二价离子对黄原胶溶液流变特性的影响研究

Effects of divalent ion on rheological properties of xanthan solution

详细研究了不同盐(钙与镁)及不同离子强度对黄原胶溶液体系流变特性的影响。通过实验发现,Ca2+及Mg2+影响黄原胶的低剪切黏度、黏度、剪切稀化指数特性以及黏弹性,还对频率扫描及动态黏弹性温度扫描时G’与G"相交点的频率、松驰时间和凝胶点温度有影响。通过动态黏度温度扫描实验,发现盐的浓度影响黄原胶溶液的构象转变温度。实验还表明,在稳态流动扫描、应变扫描、频率扫描及动态黏温扫描中二价离子对黄原胶溶液流变特性的影响明显大于一价离子,同时Ca2+的作用大于Mg2+。

The effects of different salts （including Ca^2＋ and Mg^2＋） and different ion strength on the rheological properties of xanthan solution are studied. According to the experiments, we find out that the ion like Ca^2＋ and Mg2＋ could impact on the low-shearing viscosity, viscosity, shearing thinning index and visco-elasticity as well, also has effects on the points of frequency and gelling temperature when G′=G″ in the experiments of frequency sweep and dynamic visco-elasticity temperature sweep. Based on the results of dynamic viscosity temperature sweep, concentration of salt could affect the conformation transition temperature of xanthan solution. In addition, the effect of divalent ion on rheological properties of xanthan solution is obviously greater than univalent ion on the experiments like steady viscosity sweep, strain sweep, frequency sweep and dynamic viscosity-temperature sweep, also the fact that the effect of Ca^2＋ is greater than Mg^2＋ is also observed.