Gc. Xu et al., Specific modification of polysulfone with cluster bombardment with assistance of Ar ion irradiation, REV SCI INS, 71(2), 2000, pp. 789-792
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].