All gelatin networks: 2. The master curve for elasticity
All gelatin networks: 2. The master curve for elasticity
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DOI：
10.1021/la020190m
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发表时间：
2002-09-17
期刊：
影响因子：
3.9
通讯作者：
Djabourov, M
中科院分区：
文献类型：
--
作者：
Joly-Duhamel, C;Hellio, D;Djabourov, M
明胶凝胶从各种来源（鱼和哺乳动物）的流变特性，其次是在溶胶-凝胶转变的过程中，在凝胶成熟，在非常小的变形下进行动态测量。研究了不同浓度和分子量。溶剂主要是水，但也考虑含有水和甘油的混合溶剂。制备了鱼类和哺乳动物明胶的水溶液共混物，并对其进行了流变学表征。系统的比较，建立了这些测量和那些在文件1的系列。储能模量和螺旋浓度之间的比较导致对所有研究样品有效的主曲线。这个主曲线分析的逾渗制度，在阈值附近，并在一个均匀的网络远离阈值。在逾渗制度，临界指数为2的储能模量与距离的阈值，与以前的结果一致。简要介绍了刚性网络的理论模型。充分发展的网络表现为由柔性链接连接的刚性杆（三重螺旋）的缠结组件。这项研究表明，明胶网络在小变形下的行为不像橡胶类网络，其中长的无规线圈通过局部交联或缠结连接。
The rheological properties of gelatin gels from various sources (fish and mammalian) were followed in the course of the sol-gel transition and during gel maturation, by performing dynamic measurements under very small deformations. Different concentrations and molecular weights were investigated. The solvent was mainly water, but mixed solvents containing water and glycerol were also considered. Blends of gelatins from fish and mammalian in aqueous solutions were prepared and rheologically characterized. A systematic comparison was established between these measurements and those presented in paper 1 of the series. The comparison between the storage modulus and the concentration of helices leads to a master curve valid for all the samples investigated. This master curve is analyzed in terms of the percolation regime, near the threshold and in terms of a homogeneous network far from the threshold. In the percolation regime, a critical exponent of 2 is found for the storage modulus versus the distance to the threshold, in agreement with previous results. The theoretical models for rigid networks are briefly presented. The fully developed network appears as an entangled assembly of rigid rods (triple helices) connected by flexible links. This study shows that gelatin networks under small deformations do not behave like rubber-like networks, where long random coils are connected by local cross-links or entanglements.