论文部分内容阅读
本文采用应力松弛模式研究了一价离子(K+和Na+)和二价离子(Ca2+和Mg2+)对高酰基结冷胶凝胶特性的影响。结果表明:高酰基结冷胶凝胶的应力松弛行为符合Peleg经验模型。离子浓度和离子种类对高酰基结冷胶凝胶应力松弛行为影响显著,平衡弹性模量(EA)随着离子浓度的增加呈马鞍形趋势变化,且其与凝胶硬度呈现较好的正相关(R=0.943~0.983),表明EA可以用来表征高酰基结冷胶凝胶的强度。相对于一价离子(K+、Na+)而言,二价离子(Ca2+、Mg2+)形成的凝胶强度更高,且用量更少。在相同离子浓度下,Na+形成的凝胶比K+形成的凝胶强,Ca2+形成的凝胶则比Mg2+形成的凝胶强。在16000 g下离心10 min,高酰基结冷胶凝胶保水性均在95%以上,与离子浓度基本无关,保水性能优异。高酰基结冷胶应力松弛机制是体系内部物理交联点的移动。
In this paper, the effects of monovalent ions (K + and Na +) and divalent ions (Ca2 + and Mg2 +) on the properties of high-acyl gellan gel were studied by using stress relaxation model. The results showed that the stress relaxation behavior of high acyl gellan gel accords with Peleg empirical model. Ion concentration and ionic species have significant effects on the stress relaxation behavior of high-acyl gellan gel, and the equilibrium elastic modulus (EA) showed a saddle-shaped trend with the increase of ion concentration, and showed a positive correlation with gel hardness (R = 0.943 ~ 0.983), indicating that EA can be used to characterize the acyl gellan gum strength. Divalent ions (Ca2 +, Mg2 +) form gels that are stronger and less expensive than monovalent ions (K +, Na +). At the same ion concentration, the gel formed by Na + is stronger than the gel formed by K +, and the gel formed by Ca2 + is stronger than the gel formed by Mg2 +. Centrifugation at 16000 g for 10 min, high acyl gellan gum water retention of 95% or more, and has nothing to do with the ion concentration, excellent water retention. High acyl gellan gum stress relaxation mechanism is the physical cross-point of the system movement.