Shish kebab morphology induced in polyhydroxybutyrate under shear flow
Shish kebab morphology induced in polyhydroxybutyrate under shear flow
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DOI：
10.1002/mame.200400181
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发表时间：
2004-12
影响因子：
3.9
通讯作者：
L. Sharma;Y. Ogino;T. Kanaya
中科院分区：
文献类型：
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作者：
L. Sharma;Y. Ogino;T. Kanaya
采用原位流变小角x射线散射（SAXS）、流变光散射和流变光学方法研究了不同剪切流动条件下聚羟基丁酸酯（PHB）的形貌。剪切流作用后，立即出现了高度定向的结构，并在高剪切处发现了排形核。只有鱼生长的初始阶段（我们称之为部分鱼）在过高的剪切条件下得到证实。然而，在中等剪切下，只有烤肉串被识别出来，在中等剪切下，鱼和烤肉串都没有被观察到。我们认为，这种局部的鱼是由于使用这种低分子量物种而导致稳定性不足的结果。我们得出结论，从我们的观察羊肉串机制似乎显示相似的前体形成Janeschitz-Kriegl模型。
In-situ rheo small-angle X-ray scattering (SAXS), rheo-light scattering, and rheo-optical methods were employed to investigate the resultant morphology of polyhydroxybutyrate (PHB) under varying shear flow conditions. Immediatly after shear flow application, a highly orientated structure emerged and row nucleation was identified at high shears. Only the initial stages of shish growth (we term the partial shish) were confirmed at excessively high shear conditions. However, only the kebabs were identified at medium shears, below this neither the shish nor kebab were observed. We believe this partial shish is a result of insufficient stability resulting from using such a low-molecular-weight species. We conclude that from our observations the shish kebab mechanism appears to display similarities to the Janeschitz-Kriegl model of precursor formation.