Significant influence of film thickness on the percolation threshold of multiwall carbon nanotube/low density polyethylene composite films

A series of multiwall carbon nanotube/low density polyethylene composite films with different thicknesses and different carbon nanotube volume fractions was prepared and studied. The result showed an interesting phenomenon which has not been reported before: when the thickness was reduced to the length range of the carbon nanotube filler, it could remarkably affect the percolation threshold of the composite films. Classical theories have been introduced to describe the phenomenon. This result could have significance in future applications of percolative composite thin/thick films.