کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
180211 | 459374 | 2011 | 4 صفحه PDF | دانلود رایگان |
The reduction of ω-bromoalkanoic acids Br(CH2)nCOOH at glassy carbon cathodes in aprotic polar solvents (acetonitrile, N,N-dimethylformamide or propylene carbonate) in the presence of tetraalkylammonium salts at E < − 1.7 V vs. Ag/AgCl results in a dense organic layer, covalently attached to carbon, which progressively covers the electrode surface. It was evidenced that the immobilization of alkyl chains occurs via the scission of C-Br bonds permitting an efficient coverage of the carbon surface with the layers built of alkyl links [CH2]n (3 ≤ n ≤ 11) terminated with COOH groups. The carboxyls immobilized this way were easily transformed into electroactive esters or into amides by reacting with phenols or amines, respectively. Thus grafted π-acceptor groups allowed estimating the carboxylation level as very high, ca. (1–5) × 10− 9 mol/cm2 when taking into account the starting surface area. In aqueous media, the immobilized films with long alkyl linkers visibly behave as hydrophobic layers.
Figure optionsDownload as PowerPoint slideHighlights
► Efficient grafting of ω-bromoalkanoic acids at carbon surfaces
► Immobilization of long chain alkanoic acids forming compact layers
► Carbon carboxylation permitting surfaces functionalization
► Extension to macro-modification of industrial coke powders for catalysis.
Journal: Electrochemistry Communications - Volume 13, Issue 12, December 2011, Pages 1296–1299