ACTIVATION OF POLYMER SURFACE FOR BIOMEDICAL MONOMER GRAFTING - UTILIZATION OF COLD-PLASMA IN COMPARISON WITH ION-IMPLANTATION

After 60 sec of argon plasma treatment, the hydrophobic polyolefins be came very wettable with a polar liquid due to the formation of highly polarizable groups at surface. The polyolefins after ion implantation with a dose lower than 2 x 10(14) ions.cm(-2) mainly produced simple o xidative structures; such weak surface activation resulted in a relati vely small increase of wettability. The wettability study was correspo nding with the findings of the ir-active carbonyl, the e.s.r patterns of free radicals and the oxygen functionalities in ESCA spectra. The p -HEMA grafted sample was surface-roughened nnd water-absorbable; it wa s very hydrophilic, unlike the oxygen-containing polymer surface. The likely-bonded p-HEMA was etchable and estimated smaller than 0.8 mu g. cm(-2). However, the weight increase of the grafted sample showed prob ably as high as 32 mu g.cm(-2) for PE with argon plasma pretreatment. Water absorption and HEMA homo-polymerisation on the activated sample should contribute to the shift of the grafting yield.