Electrical responses and stable behavior of polyaniline-polyurethane concave lens array film in electrolyte

We present a synthetic methodology of polyaniline-polyurethane(PANI-PU) copolymer using interfacial in situ polymerization. PANI-PU copolymer was obtained through in situ polymerization of aniline precursor and the concave lens array film was molded by water drops. The fabrication of unique structured film was obtained through a solvent evaporation self-formed system. The detailed nanostructures of the film were illustrated by scanning electron microscopy(SEM) images, which showed homogeneous structure in a close-packed hexagonal arrangement. The dimension of well-structured hexagon ranged from 10.8 μm to 12.9 μm. Sensitive electrical responses of the concave lens array film resulted in the changes of swelling/shrinkage ratio in electrolyte under various conditions. Dimensional control of the film was achieved via adjusting a series of parameters including time, voltage, concentration and type of electrolyte. The electrical responses resulted rearranged molecular chain caused by redox reaction via powered PANI. Most importantly, the film maintained its response characteristics after 16 cycles. The high stability of film could be directly attributed to PU doping, which could help the PANI enhancing the mechanical strength and chemical solubility in solution.