INFLUENCE OF RF-COLD PLASMA TREATMENT ON THE SURFACE-PROPERTIES OF PAPER

Unprinted, unsized, and sized security papers (SP) were treated under SiCl4-, O-2-, and CF4-cold plasma conditions. The plasma treatments were carried out in a stainless steel, parallel plate RF (30 kHz) reactor. The influence of plasma parameters, such as RF power, pressure, and treatment time, on the surface properties of plasma-modified security paper was examined. The newly gained surface characteristics were evaluated by Wilhelmy wettability measurements, x-ray photoelectron spectroscopy (ESCA), and scanning electron microscopy (SEM). Statistical experimental designs were used to understand the interactive effects of the plasma parameters. It was found that short treatment times and low RF power values produced the highest wettability with both SiCl4 and O-2 plasmas regardless of the sizing. Printing and durability characteristics of the plasma-treated substrates were equivalent or superior to the standard samples. Mechanisms of plasma-induced surface modifications are discussed for the paper substrates.