Specific modification of polysulfone with cluster bombardment with assistance of Ar ion irradiation

Objective: To develop a rapid method for the modification of polysulfone wi th ammonium sulfamate with the assistance of Ar ion irradiation with a mult i-source cluster deposition apparatus. These surfaces mimicking the structu re of heparin, a bioactive molecule, have a high anti-thrombosis property. Experimental Design: Polysulfone film, setting on a turning holder, was irr adiated by Ar ions during bombardment with ammonium sulfamate clusters. The Ar ion source serves for the activation of a polymer surface and a cluster ion source supplies ammonium sulfamate molecules to react with the activat ed surface. After thorough washing with de-ionized sterile water, the modif ied surfaces were evaluated in terms of the contact angle of water, element al composition, and binding state on electron spectroscopy for chemical ana lysis and platelet adhesion with platelet rich plasma. Results: The modific ation of polysulfone decreased the contact angle of water on surfaces from 82.6 degrees down to 34.5 degrees. Ammonium, amine, sulfate, and thiophene combinations were formed on the modified surfaces. The adhesion numbers of the platelet were decreased to one tenth compared to the original surface. The same process was also applied to other polymers such as polyethylene, p olypropylene, and polystyrene and similar outcomes were also observed. Conc lusion: The primary studies showed successful modification of polysulfone w ith ammonium sulfamate with the assistance of Ar ion irradiation. Since the same concept can also be applied to other materials with various substrate s, combined with the features of no solvent and no topographic changes, thi s method might be developed into a promising way for modification of polyme ric materials. (C) 2000 American Institute of Physics. [S0034-6748(00)59202 -8].