Materials World Network: In-situ NMR Studies of Processing and Deformation of Polymer/Clay Nanocomposites

纳米复合材料提供了一系列新的材料性能(机械、电学、渗透性)。这些性能是由填料和基质之间的大界面和强相互作用造成的，这是通过专门的加工实现的。这一工艺将用于聚丙烯或聚对苯二甲酸乙二酯与合成氟化云母的纳米复合材料。流变学核磁共振结合了核磁共振成像和PFG核磁共振用于流动模式的局部研究，提供了对现场加工的洞察，其中混合过程和对聚合物的有序化影响被同时研究。剪切作用下测得的残余偶极耦合提供了有关剪切诱导有序化的信息，而对分子迁移率的影响则由弛豫时间得到。剪切速率的局部变化使研究高局部剪切后聚合物的松弛成为可能。由于无机部分含有氟，因此可以高灵敏度地通过界面实现选择性激发，从而允许选择性地研究聚合物与填料的直接相互作用。用氟和硅固体核磁共振监测了填料本身的插层和分层过程。

Nanocomposites offer a new range of materials properties (mechanical, electrical, permability). These properties result from a large interface and strong interaction between filler and matrix, which is achieved by dedicated processing. The process will be investigated for nanocomposites of poly(propylene) or poly(ethylene terephthalate) with synthetic fluorinated mica. Rheological NMR a combination of NMR imaging, and PFG NMR for the localized investigation of flow pattern provides insight into the processing in situ, where the mixing process and the ordering effects on the polymer are investigated simultaneously. Information about shear-induced ordering is provided by the residual dipolar coupling measured under shear, while the influence on molecular mobility is derived from relaxation times. Local variations in the shear rate permit the investigation of the relaxation of the polymer after high local shear. Since the inorganic part contains fluorine selective excitation across the interface is achieved with high sensitivity permitting the selective investigation of the polymer in direct interaction with the filler. The intercalation and delamination process on filler itself is monitored by fluorine and silicon solid-state NMR.