RHEOLOGICAL PROPERTIES OF AQUEOUS AGAROSE-GELATIN GELS
RHEOLOGICAL PROPERTIES OF AQUEOUS AGAROSE-GELATIN GELS
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DOI：
10.1111/j.1745-4603.1980.tb00325.x
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发表时间：
1980-01-01
影响因子：
3.2
通讯作者：
WATASE, M
中科院分区：
文献类型：
--
作者：
MORITAKA, H;NISHINARI, K;WATASE, M
测定了1-5%琼脂糖凝胶、7.5-40%明胶凝胶和不同浓度的两种水胶体混合凝胶的熔融温度。对于含有0.5%琼脂糖和2.5-20%明胶的混合凝胶，在0.05 HZ处的动态粘弹常数也是定量的。在单组分凝胶中，熔融温度随水胶体浓度的增加而升高。明胶凝胶的熔化温度低于琼脂糖凝胶(22-31℃比69-80℃)，且对浓度的依赖性较小。当明胶浓度较低(2.5-6.25%)时，混合凝胶的熔融温度更接近琼脂糖凝胶，而当明胶浓度较高(7.5-20%)时，混合凝胶的熔化温度更接近明胶。储能模数随温度的升高而降低，表明凝胶中非共价交联物的热破裂行为强于网络的熵行为。储能模数和动态粘度的温度依赖性随明胶浓度的增加而增大。根据这些结果和活化能的测定，得出结论：在琼脂糖/明胶混合凝胶中，这两种物种在高浓度下形成了相互干扰的单独网络。
Melting temperatures were determined for 1‐5% agarose gels, 7.5‐40% gelatin gels and mixed gels of different concentrations of the two hydro‐colloids. The dynamic viscoclastic constants were also quantified at 0.05 HZ for mixed gels containing 0.5% agarose and 2.5–20% gelatin.In single component gels, the melting temperature increased with hydrocolloid concentration. The melting temperature of gelatin gels was lower than that of agarose gels (22–31°C vs 69–80°C) and less concentration dependent. The melting temperature of mixed gels was more similar to that of agarose gels at low (2.5–6.25%) gelatin concentrations and more similar to that of gelatin gels at high (7.5–20%) gelatin concentrations. The storage modulus decreased with increasing temperature indicating that the thermal rupturing of the noncovalent crosslinks in the gels was stronger than the entropic behavior of the network. The temperature dependence of the storage modulus and of the dynamic viscosity increased with gelatin concentration. Based on these results and on the determination of the activation energy it is concluded that, in mixed agarose/gelatin gels, the two species form individual networks which interfere with one another at high concentrations.