Silver microflowers and large spherical particles: Controlled preparation and their wetting properties

In this article, we report a simple wet-chemical method to prepare silver microflowers and large spherical particles. The formation of the two different microstructures of silver is based on the reduction of AgNO3 by para-phenylenediamine in aqueous medium at room temperature. The controlling of the silver microstructures can be achieved only by adjusting the concentration of the reactants. It is found that the two different silver microstructures display opposite wetting properties. Large spherical silver particles exhibit superhydrophilic properties with a contact angle (CA) of close to 0 degrees, microflower-like silver particles exhibit highly hydrophobic properties with CA about 132 degrees. X-ray diffraction (XRD), X-ray photoelectron spectra (XPS) and UV-vis spectra are used to characterize the chemical structure of the obtained products. (c) 2007 Elsevier Inc. All rights reserved.