Accumulation of undesired biological material on surfaces, called biofouling, is a cause of problems in many fields, including the shipping industry, paper and food processing and, naturally, in biomedical applications. Current technologies applied to counter fouling are not environmental friendly, so research is directed finding coatings that prevent the adsorption of biomaterial and the settlement of microorganisms.
Promising candidate materials are oligo(Ethylene glycol) methacrylates and zwitterionic polymers. These materials usually exhibit zero net charge and high affinity to bind water molecules. The bound water greatly influences the structure of the molecule. There is an optimum of the anti-fouling properties of a polymer thin film depending on its thickness. Since a similar dependence may be observed investigating the swelling of the polymer films, determining the wet structure of polymer films, and identifying the binding sites along the polymer chains, will contribute greatly to the understanding of the underlying mechanisms.
As the optical contrast between the proteins, the polymer and the surrounding medium is very low, neutron reflectometry offers a unique method to determine the wet structure. Utilizing isotope variation techniques the sensitivity of the method is greatly enhanced. Thus I use this method to determine both the dry and hydrated structure of thin polymer films.
