High-Conductivity Two-Dimensional Polyaniline Nanosheets Developed on Ice Surfaces.

A new method to develop two-dimensional PANI nanosheets using ice as a removable hard template is presented. Distinctly high current flows of 5.5 mA at 1 V and a high electrical conductivity of 35 S cm(-1) were obtained for the polyaniline (PANI) nanosheets, which marked a significant improvement from previously values on other PANIs reported over the past decades. These improved electrical properties of ice-templated PANI nanosheets were attributed to the long-range ordered edge-on π-stacking of the quinoid ring, ascribed to the ice surface-assisted vertical growth of PANI. The unprecedented advantages of the ice-templated PANI nanosheets are two-fold. First, the PANI nanosheet can be easily transferred onto various types of substrates via float-off from the ice surfaces. Second, PANI can be patterned into any shape using predetermined masks, and this is expected to facilitate the eventual convenient and inexpensive application of conducting polymers in versatile electronic device forms.