SURFACE STUDIES OF PLASMA SOURCE ION-IMPLANTATION TREATED POLYSTYRENE

The plasma source ion implantation (PSII) was utilized to improve the wettability and the stability of surface layer formed in the modificat ion of polymeric materials. Polystyrene was treated with different kin ds of plasma ions to render the surface more hydrophilic or hydrophobi c. Hydrophobic recovery of PSII-treated polystyrene was also observed as a function of aging time, aging temperature, and treatment paramete rs. Treatment parameters involve kinds of gases, pressure, plasma powe r, pulse frequency, pulse voltage, etc. To study the effect of inert g as on hydrophobic recovery, polystyrene samples were prepared by heliu m, argon, or gas-mixture treatment. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been used to interpret the PSII-treated po lystyrene surface and its hydrophobic recovery, with the assistance of x-ray photoelectron spectroscopy and water contact angle measurements . TOF-SIMS spectra of O-18(2) PSII-treated samples showed the presence of O-18-containing peaks from the modified surfaces. PSII modificatio ns provide more stable surfaces of polystyrene as a function of aging time than plasma treatments. The comparison of aging behavior data all owed for examination of the differences in the stability of the functi onality introduced by the two different treatment techniques. (C) 1998 American Vacuum Society.