Journal of Colloid and Interface Science, Vol.180, No.1, 15-21, 1996
Fabrication of Aerogel-Like Structures by Agglomeration of Aerosol-Particles in an Electric-Field
Aerosol particles of different materials (carbon, brass, and steel) produced by laser evaporation at atmospheric pressure were exposed to an electric field. The primary particles were 1 to 10 nn in diameter depending on the target material, It is shown that number concentrations of electrically neutral particles confined in the chamber depend on the field strength. Photomicrographs show the formation of bushlike structures from aerosol particles flowing through the chamber on the electrodes, accompanied by wirelike structures spanning the distance between the electrodes, about 0.5 cm. The wirelike structures continued growing both in number and in width by adding subbranches. The overall structure which filled the volume between the electrodes has certain similarities to an aerogel, which is a nanostructured material with a high void fraction, composed of nanometer particles that are rigidly bonded. However, structures formed by the aerosol process are less rigid and show an anisotropic form, and for this reason are called aerogel-like.