Electrostatic Deposition of Aerosol Particles Generated from an Aqueous Nanopowder Suspension on a Chemically Treated Substrate

The state of electrostatically deposited aerosol particles from a suspension that contains TiO2 particles on the surface of a solid substrate using electrospray was demonstrated. The particles were initially electrosterically stable in 7.5 wt% aqueous solution with a mean particle size of 50 nm. During deposition, the particles were pumped with different flow rates between 0.6 and 1.2 mL/h through a stainless steel capillary tube of 0.1mm inner diameter. The particles were emitted at the tip of the capillary tube as an electrified liquid cone before forming into a highly charged droplet. For comparison, two types of substrate surfaces with and without chemical treatment were prepared. Atomic force microscopy (AFM) scanning and contact angle measurements showed that surface treatment increased the substrate roughness and created a hydrophilic surface. Raman analysis also showed the existence of an oxide layer and a P-O network on the treated substrate. Field emission scanning electron microscopy FE-SEM image analysis showed that more TiO2 particles were deposited on the treated substrate than on the untreated substrate. (C) 2010 The Japan Society of Applied Physics