IMPROVING WETTABILITY OF POLYCARBONATE AND ADHESION WITH ALUMINUM BY AR+ ION IRRADIATION

Improving wettability of the polycarbonate (PC) surface to triple dist illed water has been carried out by Ar+ ion irradiation with blowing o xygen gas. The amount of Ar+ was changed from 10(14) to 5 X 10(16) ion s/cm(2) at 1 keV energy by a Kaufman-type ion source. Contact angle of the water to PC has been reduced from 78 degrees to 50 degrees with A r+ irradiation, and to 12 degrees with Ar+ irradiation in various vacu um pressures adjusted by oxygen gas flow rate (0-4 seem). Strong O-H s tretching vibration peaks at about 3370 cm(-1) on FT-IR spectra of the polymer appeared after the surface treatments, and the wetting angle of the treated PC was returned to its value (78 degrees) when the PC w as exposed in air environment. The minimum contact angles were maintai ned with the same value when the irradiated polymers were kept in dilu te HCl solution. The improved wettability and surface chemical reactio n by Ar+ ion irradiation with oxygen was explained by the formation of a hydrophilic functional group. Enhanced adhesion between aluminum an d PC was confirmed by the scotch tape test, and was discussed with rel ation between the hydrophilic group on the polymer surface and the dep osited metal.