Hydrophilic and hydrophobic groups were selectively incorporated on the poly(methyl methacrylate) [PMMA] surface using a Xe2 excimer lamp and ArF excimer laser. With this new technique, a protein adsorption on the PMMA surface can be controlled.
PMMA was firstly irradiated with a Xe2 excimer lamp in the presence of perfluoropolyether [PFPE] liquid layer to incorporate CF3 groups, and secondly, the PMMA surface was irradiated by an ArF excimer laser through a patterned reticle in the presence of water to incorporate OH groups or NH2 groups in an ammonia gas ambience. The area ratio of hydrophilic and hydrophobic of the modifying sample was made to 1:3, 1:1, and 3:1. The results showed that the fibrin absorption on the sample with hydrophilic and hydrophobic micro domains depended on the area ratio of the hydrophilic and hydrophobic. The absorption coefficient of the amide band remarkably decreased with increase in water contact angle. Furthermore, it was confirmed that the absorption coefficient of fibrin decreased as the interval of CF3 and OH or NH2 groups was narrowed from 250 to 20 μm, and the fibrin sticking on the modified surface with the 20 μm hydrophilic and hydrophobic micro domains was reduced to one-twenty of that on the untreated sample.