Patterned Conductive Polyaniline Films Fabricated Using Lithography and In Situ Polymerization

摘要

In this article, we describe a novel bottomup technique for the preparation of transparent conductive films of polyaniline (PANI). A UV-curable photoresist was formulated containing an acrylate-endcapped urethane oligomer [UA(PPG400)], acrylic acid, a photoinitiator, and a reactive diluent (tripropylene glycol diacrylate), and the lithography techniques were used to pattern the structure with line widths/spaces of 100 lm/100 lm, 10 lm/10 lm,and 5 lm/5 lm on a polyethylene terephthalate substrate. The carboxylic acid units on the surface of the patterned photoresist interacted with the aniline monomer units to form anilinium complexes; using ammonium persulfate as a chemical oxidant, we then synthesized a layer of conductive PANI on the surface of the patterned resist through in situ polymerization. The optimal conductivity of the PANI conductive film was ca. 10 S/cm. The thin film was characterized, and its physical properties investigated using Fourier transform infrared spectroscopy, UV–Vis spectroscopy, differential scanning calorimetry, optical and atomic force microscopy, and four-point probe conductivity measurements.