Formation of nano-rod and nano-particles of polyaniline using Langmuir-Blodgett technique

Abstract We present the formation of nano-structures especially nano-rod and nano-particles of polyaniline (PANI) using Langmuir–Blodgett (LB) technique of molecular deposition. Decrease in the pH of the sub-phase of LB trough increases level of doping (protonation) of polyaniline emeraldine base to emeraldine salt and causes doping induced nano-structure formation. High resolution transmission electron microscopy reveals that anisotropic rod like nano-structures of PANI of diameter less than 50 nm are formed at pH 1 while pH 3 induces the formation of dispersed nano-particle of diameter 15 nm. On the contrary, connected lump (aggregation) type nano-structures of PANI are formed at a higher value of pH 6.

[1]  L. Huo,et al.  Preparation and characterization of doped polyaniline films , 1999 .

[2]  R. Lal,et al.  Electrochemistry of polyaniline Langmuir–Blodgett films , 1998 .

[3]  H. Stubb,et al.  Conducting Langmuir-Blodgett films of polyaniline: Fabrication and charge transport properties , 1997 .

[4]  Charles R. Martin,et al.  Nanomaterials: A Membrane-Based Synthetic Approach , 1994, Science.

[5]  A. Riul,et al.  Characterization of Langmuir-Blodgett films of parent polyaniline , 1996 .

[6]  L. Dai,et al.  Conducting Polyaniline Nanotubes by Template-Free Polymerization , 2001 .

[7]  Richard B Kaner,et al.  A general chemical route to polyaniline nanofibers. , 2004, Journal of the American Chemical Society.

[8]  A. Riul,et al.  Composite Langmuir–Blodgett (LB) films of polyaniline and cadmium stearate , 1998 .

[9]  S. V. Mello,et al.  Langmuir and Langmuir-Blodgett films of parent polyaniline doped with functionalized acids , 1994 .

[10]  B. H. Weiller,et al.  Nanostructured polyaniline sensors. , 2004, Chemistry.

[11]  Xinyu Zhang,et al.  Synthesis of polyaniline nanofibers by "nanofiber seeding". , 2004, Journal of the American Chemical Society.

[12]  Yadong Jiang,et al.  Fabrication and characterization of polyaniline-based gas sensor by ultra-thin film technology , 2002 .

[13]  Chun-Guey Wu,et al.  Conducting Polyaniline Filaments in a Mesoporous Channel Host , 1994, Science.

[14]  J. Cheung,et al.  New developments in the Langmuir-Blodgett manipulation of electroactive polymers , 1992 .

[15]  Frank Ko,et al.  Electrostatic fabrication of ultrafine conducting fibers: polyaniline/polyethylene oxide blends , 2000 .

[16]  Richard B. Kaner,et al.  Polyaniline Nanofiber Gas Sensors: Examination of Response Mechanisms , 2004 .

[17]  T. Berzina,et al.  Deposition of uniform conductive polyaniline films and approach for their patterning , 2002 .