We report the studies of conjugated polymers, polyaniline thin films, with a near-field scanning optical microscope. Because of the absorption variation in different oxidation states, transmission-mode near-field scanning optical microscope images were employed to map out the distribution of the oxidation states on a submicrometer scale. When the near-field wavelength is varied (between 632.8 and 543.5 nm), the phase separation between the oxidized and the reduced repeated units, with domain sizes on a nanometer-length scale, is observed.
© 1997 Optical Society of America
Original Manuscript: August 20, 1996
Revised Manuscript: December 2, 1996
Published: May 20, 1997
Pei-Kuen Wei, Jui-Hung Hsu, Wunshain Fann, Kuen-Ru Chuang, Hsun-Tsing Lee, and Show-An Chen, "Phase separation in polyaniline with near-field scanning optical microscopy," Appl. Opt. 36, 3301-3304 (1997)