Dynamic scaling for gelation of a thermosensitive chitosan-β-glycerophosphate hydrogel
Dynamic scaling for gelation of a thermosensitive chitosan-β-glycerophosphate hydrogel
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DOI：
10.1007/s00396-007-1789-3
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发表时间：
2008-04
影响因子：
2.4
通讯作者：
Jaepyoung Cho;M. Heuzey
中科院分区：
文献类型：
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作者：
Jaepyoung Cho;M. Heuzey
采用流变仪研究了壳聚糖-β-甘油磷酸盐体系的热凝胶化过程。在等温条件下进行两种聚合物浓度的凝胶化，以检查各种温度（35至65 °C）对溶胶-凝胶转变的影响。利用振荡剪切实验验证了凝胶点的标度行为（G′~G″~ ωn），并发现幂律指数n在一定程度上依赖于壳聚糖浓度和温度。根据相对于凝胶化时间的距离（η）分析溶液的零剪切粘度（η0）和凝胶的低频模量（Ge）。这两个性质与α呈幂律关系，η0~ ε −和Ge ~ ε z，且指数随温度升高略有增加。动态标度理论预测了指标之间的关系，即，n=z/（z+s），这与实验结果相当吻合。
This paper investigates the thermal gelation of a chitosan-β-glycerophosphate system using rheometry. The gelation, performed for two polymer concentrations, was achieved in isothermal conditions to examine the effect of various temperatures (between 35 and 65 °C) on the sol-gel transition. The oscillatory shear data was used to verify the scaling behavior (G′~G″~ ωn) at the gel point, and the power-law indexnwas found to be dependent to some extent on chitosan concentration and temperature. The solutions zero shear viscosity (η0) and the gels low frequency modulus (Ge) were analyzed in terms of the relative distance to gelation time (ɛ). The two properties showed power–law relationships withɛ, i.e.,η0~ɛ−sandGe~ɛz, and the indexes slightly increased with temperature. The dynamic scaling theory predicts a relationship between the indexes, i.e.,n=z/(z+s), and this was in reasonably good agreement with the experimental findings.