The rheology of collapsing zeolites amorphized by temperature and pressure
The rheology of collapsing zeolites amorphized by temperature and pressure
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DOI：
10.1038/nmat963
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发表时间：
2003-09-01
期刊：
影响因子：
41.2
通讯作者：
Sankar, G
中科院分区：
文献类型：
--
作者：
Greaves, GN;Meneau, F;Sankar, G
低密度沸石在温度远低于相同成分但具有常规密度的晶体的熔点时坍塌成刚性无定形。在这里，我们通过使用一系列实验技术，展示了非晶化现象是如何依赖于时间的，以及沸石在温度和压力下有序-无序转变的动力学是如何等效的。结果，不稳定的热压区可以绘制成图，这是多变质作用的指示。此外，这些区域的边界取决于温度或压力上升的速度。通过直接比较等效熔体中崩塌的流变学和结构松弛，我们得出结论，沸石像非常强的液体一样非晶化，如果压缩发生缓慢，这是可能的。导致完美眼镜的合成。
Low-density zeolites collapse to the rigid amorphous state at temperatures that are well below the melting points of crystals of the same composition but of conventional density. Here we show, by using a range of experimental techniques, how the phenomenon of amorphization is time dependent, and how the dynamics of order-disorder transitions in zeolites under temperature and pressure are equivalent. As a result, thermobaric regions of instability can be charted, which are indicative of polyamorphism. Moreover, the boundaries of these zones depend on the rate at which temperature or pressure is ramped. By directly comparing the rheology of collapse with structural relaxation in equivalent melts, we conclude that zeolites amorphize like very strong liquids and, if compression occurs slowly, this is likely to. lead to the synthesis of perfect glasses.