Nanoscale wool particles were prepared from wool fibers by a special pretreatment with the aid of specially designed machinery and techniques. Scanning electron micrographs showed that the particle sizes of wool powders produced from wool fibers approximately 8-20 mu m in diameter decreased from a microscale to a nanoscale after three stages of pulverization, which were further confirmed with a laser particle size analyzer. Fourier transmission infrared analysis showed that there were no substantial changes in the chemical structure of the wool after the pulverization processes. The wool powders after the second and third pulverizations slightly differed from that of the wool fiber and the particles after the first pulverization, with greater amounts of the secondary amine groups, amide groups, C=S stretching vibrations, and O-H bonds. X-ray diffraction analysis showed that the crystallinity of the wool powders decreased when the particle sizes decreased, particularly at nanoscales. (c) 2007 Wiley Periodicals, Inc.