Effects of Solvent Conductivity on the Self-Limiting Electrospray Deposition (SLED) of Polymer Films

Self-Limiting Electrospray Deposition (SLED) is a derivative of the classic electrospray process for depositing both homogenous and composite films. The unique advantages of SLED are the abilities to deposit monodisperse and conformal coatings onto complex surfaces of both conducting and insulating surfaces. The resulting microstructure of the deposited film depends on numerous input parameters including the polymer characteristics, solution concentration, applied voltage, separation distance, and solvent conductivity. In this work, the effects of solvent conductivity on SLED polystyrene films are evaluated. The addition of ammonium salts and mixtures of various solvents such as acetonitrile are studied. Finally, the effects of solvent conductivity on the hierarchical microstructure of the deposited films are evaluated via scanning electron microscopy and compared. Preliminary results indicate that an increase in solvent conductivity results in a decrease in size of PS particles deposited via SLED resulting in a more uniform film.