Microwave absorption behaviors of tetra-needle-like ZnO whiskers

A novel type of microwave absorption coating was prepared using tetra-needle-like zinc oxide whiskers as the main functional agent. The results of the experiments show that the composite coatings containing ZnO whisker appear to have good efficiency of microwave absorption, and the effect is influenced by the aspect ratio (length to diameter, L/D), the content of the T-ZnO whiskers and the resistivity of the whiskers. Microwave-heat transformation of this kind of whisker and its composite was investigated, and the results indicated that the apparent density affected the efficiency C. The mechanism of microwave absorption and microwave-heat of the heat generating. The suitable value of the apparent density is 0.16-0.18 g/cm(3) transformation was explained by the semiconductive networks formed by the tetra-needle shape, diffuse reflections results from quasi-antenna, multipoles due to charge concentration and the multi-interfaces in the composites. (c) 2005 Elsevier B.V. All rights reserved.