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Chemical assays of end‐groups displayed on the surface of poly(ethylene terephthalate) (PET) films and membranes by radiolabeling
Author(s) -
Boxus Thierry,
DeldimeRubbens Michèle,
Mougenot Patrick,
Schneider YvesJacques,
MarchandBrynaert Jacqueline
Publication year - 1996
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/(sici)1099-1581(199607)7:7<589::aid-pat551>3.0.co;2-b
Subject(s) - membrane , materials science , surface modification , polymer chemistry , ethylene , chemical modification , carbodiimide , microporous material , covalent bond , scanning electron microscope , chemical engineering , chemistry , organic chemistry , biochemistry , engineering , composite material , catalysis
Poly(ethylene terephthalate) (PET) films and track‐etched microporous membranes naturally display, on their surfaces, reactive chain‐ends, i.e. carboxyl and hydroxyl functions. These were assayed by suitable activation (reaction with carbodiimide and tosyl chloride, respectively), followed by coupling with 3 H‐lysine and liquid scintillation counting of the sample‐associated radioactivity. Values ranging between 5 and 30 pmol/cm 2 (open surface) of labeled end‐groups were obtained, depending on the physico‐chemical nature of the samples. Basic hydrolysis enriched the PET films with both types of endings (15–25 pmol/cm 2 ). Reduction of films with the NaBH 4 ‐catechol complex in tetrahydrofuran enriched their surfaces with hydroxyl groups. However, this procedure was not readily applicable to the surface modification of membranes; we observed an erosion effect that was confirmed by scanning electron microscope analyses. In contrast with the reduction process, the oxidation with KMnO 4 in 1.2N H 2 SO 4 could be easily applied to the modification of either films or membranes; their surfaces were significantly enriched with carboxyl groups (15–50 pmol/cm 2 ). This surface modification strategy has been used for the covalent coupling of adhesive proteins on PET membranes developed as supports for cell cultivation.