Functional group quantification on epoxy surfaces by chemical derivatization (CD)‐XPS

In this study, epoxy-terminated silicon oxide surfaces were chemically derivatized with trifluoroacetic anhydride (TFAA) and 4-(trifluoromethyl)-benzylamine (TFMBA) and analyzed by X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy and water contact angle measurements. TFAA was used for quantitative derivatization to determine the amount of reactive epoxy groups on these surfaces. Furthermore, epoxy-terminated surfaces were derivatized with TFMBA (a model compound for biomolecules with an amino linker) yielding secondary amines because of formation of covalent C-N bonds between TFMBA and the epoxy films. Fluorine being part of TFAA and TFMBA composition was used to follow the progress of the chemical derivatization reaction. Both derivatization agents - TFAA and TFMBA - gave comparable reaction yields of similar to 60% on epoxy silicon surfaces, whereas on epoxy glass slides, the derivatization yields were considerably lower (30-40%). The protocol for attachment of TFMBA (model compound) on epoxy-modified surfaces was adapted to (bio) molecules with an amino linker, e.g. carbohydrates to prepare carbohydrate-functionalized biointerfaces. Copyright (C) 2014 John Wiley & Sons, Ltd.