Unraveling bilayer interfacial features and their effects in polar polymer nanocomposites

XH Li and S He and YD Jiang and J Wang and Y Yu and XF Liu and F Zhu and YM Xie and YY Li and C Ma and ZH Shen and BW Li and Y Shen and X Zhang and SJ Zhang and CW Nan, NATURE COMMUNICATIONS, 14, 5707 (2023).

DOI: 10.1038/s41467-023-41479-0

Polymer nanocomposites with nanoparticles dispersed in polymer matrices have attracted extensive attention due to their significantly improved overall performance, in which the nanoparticle-polymer interface plays a key role. Understanding the structures and properties of the interfacial region, however, remains a major challenge for polymer nanocomposites. Here, we directly observe the presence of two interfacial polymer layers around a nanoparticle in polar polymers, i.e., an inner bound polar layer (similar to 10 nm thick) with aligned dipoles and an outer polar layer (over 100 nm thick) with randomly orientated dipoles. Our results reveal that the impacts of the local nanoparticle surface potential and interparticle distance on molecular dipoles induce interfacial polymer layers with different polar molecular conformations from the bulk polymer. The bilayer interfacial features lead to an exceptional enhancement in polarity-related properties of polymer nanocomposites at ultralow nanoparticle loadings. By maximizing the contribution of inner bound polar layer via a nanolamination design, we achieve an ultrahigh dielectric energy storage density of 86 J/cm(3), far superior to state- of-the-art polymers and nanocomposites.

Return to Publications page