MODIFICATION OF CATHETER MATERIALS BY COATING WITH POLYMER LAYERS CONTAINING SILVER

The surface of polyurethane based catheter material or of silicon wafe rs as model surfaces were modified by spin coating of solutions of pol y(ethylene oxide) or poly(vinyl alcohol) in water. For the incorporati on of silver ions, silver nitrate was added to some of the solutions o r the as-cast surfaces were dipped into AgNO3 solution. Furthermore, s amples coated with a thin layer of metallic silver were prepared by de position of silver vapor in vacuum. The as-prepared surfaces were stud ied by atomic force microscopy and X-ray photoelectron spectroscopy. D uring the spin coating of the solutions containing AgNO3, clusters of the silver component were formed. They were well dispersed in a poly(v inyl alcohol) matrix but act as nucleation agents in poly(ethylene oxi de) where then large spherulites are formed. The surface compositions of coated samples and the depth profiling were carried out by angle de pendent X-ray photoelectron spectroscopy.