We investigated the resistance response mechanisms and provided a resistance regulation strategy for conductive nanocomposites.

SiO₂-epoxy nanocomposites with different SiO₂ nanoparticle contents are synthesized. Some micro/nanoscopic structural characterizations are studied, including the various degrees of nanoparticle dispersion, free-volume contents, and the interface between the nanoparticles and the polymer matrix. The thermomechanical properties of nanocomposites are also investigated. The influence of nanoparticle contents on the structural characterization is qualitatively and quantitatively analyzed. This study will be helpful for the structural design and property evaluation of nanocomposites.

In this paper, a discovery is reported that carbon nanotube (CNT) films can change in-plane Poisson’s ratios from negative to positive during a uniaxial tensile loading. First, in situ experimental investigations of the deformation fields about the CNT films fabricated using vertically aligned CNT arrays are performed by digital speckle correlation method, the novel phenomenon for changing Poisson’s ratio from negative to positive during the stretching process is discovered. Furthermore, the physical mechanisms for changing the Poisson’s ratio from negative to positive are explained based on the interactions among CNTs. Finally, a potential engineering application for designing intelligent connector is proposed based on the intriguing Poisson’s ratio of CNT films.