Prevention of biofilm attachment by plasma treatment of polyethylene Available to Purchase

In this work, ultrahigh molecular weight polyethylene (UHMWPE) was treated with low-pressure nitrogen plasma for improved biofouling resistance. The plasma-treated surface showed a decrease in water contact angle from 85° for the untreated surface to 40° for the nitrogen (N₂) plasma-treated surface. Optical emission spectroscopy analysis reveals the presence of excited species of carbon and hydrogen (unstable ionised forms) associated with bond breaking, hydrogen abstraction and chain scission processes. The average roughness for the untreated UHMWPE surface was 1·0 μm, which increased to 2·2 μm due to etching with plasma treatment. The nanomechanical properties of the samples such as hardness and modulus were assessed by nanoindentation tests. These tests showed that plasma affects only a few nanometres of the polymer. The polymers were studied for Escherichia coli biofilm formation, and they were imaged using an optical microscope and atomic force microscope. It was observed that plasma treatment significantly reduced the bacterial attachment on the surface compared to the untreated polymer. This can be attributed to the decreased hydrophobicity of the surface, which prevents the bacterial interactions with the surface.