the functional characterization and the tailor-made derivati-Surface functionalization of polyethylene terephthalate film and zation of PET surfaces (films and membranes).
track-etched microporous membranes was performed using or-Our original methodology (4, 5) is based on highly sensiganic synthesis at the solid-liquid interface. The hydroxyl chain tive radiochemical assays in which the labels are covalently ends, naturally occurring in the membranes or created by basic fixed on surface-exposed functional groups, using the techhydrolysis in the film, were activated by reaction with p-toluniques of organic chemistry at the solid-liquid interface.
enesulfonyl chloride and then coupled to [4,5-3 H]lysine used as
The advantage of this wet-chemistry approach (6, 7) is the a model of water-soluble bioactive molecules. The ratios of derivatpossibility of performing selective chemical transformations ization were determined by liquid scintillation counting of the using a range of mild conditions which restrict the changes radioactivity associated with the samples. The hydroxyl chain ends were further reacted with 4,4-methylene di(phenyl isocyanate); to specific surface groups and do not alter the structure of the resulting surfaces equipped with sensitive isocyanate spacers the bulk. Moreover, the derivatization reactions using radiowere assayed as before using [4,5-3 H]lysine. The ranges of derivatactive labels are conducted in water solution at room temperization were from 5 to 60 pmol of fixed amino acid per open ature, a situation that mimics the conditions likely to be surface unit (cm 2 ). Some samples were also analyzed by X-ray encountered in the covalent coupling of biologically active photoelectron spectroscopy.