Confined geometry, glassy polymers

The mechanical connectivity between the filler particles is provided by a flexible, nanoscopic bridge of glassy-like polymer, resulting from the immobilization of the rubber chains in the confining geometry close to the gap. 

Experiments in confined geometries, particularly in the case of polymers, require several considerations. Besides the existence or absence of interfaces, the geometry itself plays an important role. ID confinement geometiy (thin films) and 2D confinement (nanotubes and nanorods) implies that the polymer chain has to accommodate in an anisotropic fashion, whereas in 3D (nanospheres) the confinement is isotropic. In each of the above mentioned experiments, interfaces play a fundamental role. In the particular case of ID confinement, as for supported thin films, it has been demonstrated that there is a strong impact of interfaces on the static and dynamical properties of the polymer [38]. These interfaces also appear in the case of polymers confined in cylindrical pores. Tanaka and coworkers demonstrated that the slower dynamics near a substrate is related to a wall-induced enhancement of glassy structural order , which is a manifestation of strong interparticle correlations [39]. The presence of the solid interface favours the presence of clusters with a preferential bond orientational order. When the polymer system under these circumstances is semicrystaUine, the crystallization process is modified in two different ways. On one hand, the slower dynamics due to the polymer-chain interactions delays the crystallization process [12, 20]. On the other... 

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