Silver-nanoparticle-doped poly(9-vinylcarbazole) (PVK) nanocomposites were prepared via the reduction of Ag+ ions and the self-assembly of PVK on AgNO3 aqueous solution surfaces. The formed composite nanostructures depended strongly on the experimental temperature. Thick round disks f PVK Surrounded by discrete Ag nanoparticles and/or with irregular holes formed at room temperature; nanotubes and micronetworks doped with Ag nanoparticles formed at about 30-40 degrees C, and networks formed at higher temperature. Further investigation revealed that the nanotubes were transformed from thin round disks. The length of the PVK/Ag composite nanotubes were longer than 10 mu m, and the average size of the embedded Ag nanoparticles was found to be about 3.5 nm. The composite networks were composed of round pores with diameters of several hundred nanometers and fine silver nanoparticles embedded in the thin polymer films that covered the pores. The formation of the nanotubes was a very interesting self-assembly phenomenon of the polymer at the air-water interface that has not been reported before. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 116: 252-257, 2010