High performance electrical conductive composites with ultralow percolation threshold

摘要

Particle-laiden polymer composites are a broad range of functional materials. Most of the polymer composite properties are strongly dependent on the filler loading level, which typically have an abrupt change near the critical filler loading. This phenomenon has been widely investigated and theoretically modeled by percolation theory. Generally, controlling the percolation threshold became a dominating approach to adjust the percolation properties of a composite and have attracted intensive interests. Here we report a generized strategy to control over the percolative properties in polymer composite. The percolation threshold of the composite <4 v% was demonstrated in polymer composite by using the commercially available microparticles, comparing to a threshold value of ∼18 v% in a conventional composite. For the electrically conductive composite, a reduction of 40 wt% of filler loading was achieved while keeping its conductivity. The percolation threshold controls not only increase the percolation properties of the electrical conductivity, but also the thermal conductivity and dielectric properties of the composites. The strategy described can be implemented in most of the current polymer composite manufacturing processes. The findings reported here are expected to revolutionize the conventional fields of composite materials.