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A study of surface modification and anchoring techniques used in the preparation of monolithic microcolumns in fused silica capillaries
Author(s) -
Courtois Julien,
Szumski Michal,
Byström Emil,
Iwasiewicz Agnieszka,
Shchukarev Andrei,
Irgum Knut
Publication year - 2006
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200500294
Subject(s) - silanization , photopolymer , x ray photoelectron spectroscopy , silane , methacrylate , materials science , surface modification , chemical engineering , wetting , surface roughness , contact angle , silanes , polymer , etching (microfabrication) , (hydroxyethyl)methacrylate , chemistry , composite material , copolymer , polymerization , layer (electronics) , engineering
Based on a survey of the literature on pretreatment of fused silica capillaries, 3 etching procedures and 11 silanization protocols based on the vinylic silane 3‐((trimethoxysilyl)propyl) methacrylate (γ‐MAPS) were found to be most representative as a means of ensuring attachment of in situ prepared vinylic polymers. These techniques were applied to fused silica capillaries and the success in establishing the intended surface modification was assessed. X‐ray photoelectron spectroscopy (XPS) was used to characterize the chemical state of the surface, providing information regarding presence of the reagent bound to the capillary. Wetting angles were measured and correlated with the XPS results. An adherence test was done by photopolymerization of a 2 mm long plug of 1,6‐butanediol dimethacrylate in the prepared capillaries and evaluation of its ability to withstand applied hydraulic pressure. SEM was also performed in cases where the plug was released or other irregularities were observed. Finally, the roughness of the etched surface, considered to be of importance, was assessed by atomic force microscopy. Alkaline etching at elevated temperature provided a surface roughness promoting adhesion. The commonly used silanization protocols involving water in the silanization or washing steps gave inadequate surface treatment. The best silanization procedure was based on toluene as a solvent.