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Surface modification of PDMS microchips with poly(ethylene glycol) derivatives for μTAS applications
Author(s) -
Campos Richard Piffer Soares,
Yoshida Inez Valeria Pagotto,
Silva José Alberto Fracassi
Publication year - 2014
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201300531
Subject(s) - contact angle , ethylene glycol , surface modification , materials science , wetting , substrate (aquarium) , adsorption , chemical engineering , rhodamine b , aqueous solution , polydimethylsiloxane , rhodamine , analytical chemistry (journal) , fluorescence , chromatography , chemistry , nanotechnology , organic chemistry , composite material , oceanography , physics , photocatalysis , engineering , geology , catalysis , quantum mechanics
In this work is presented a method for the modification of native PDMS surface in order to improve its applicability as a substrate for microfluidic devices, especially in the analysis of nonpolar analytes. Therefore, poly(ethylene glycol) divinyl ether modified PDMS substrate was obtained by surface modification of native PDMS. The modified substrate was characterized by attenuated total reflectance infrared spectroscopy, water contact angle measurements, and by evaluating the adsorption of rhodamine B and the magnitude of the EOF mobility. The reaction was confirmed by the spectroscopic evaluation. The formation of a well‐spread water film over the surface immediately after the modification was an indicative of the modified surface hydrophilicity. This characteristic was maintained for approximately ten days, with a gradual return to a hydrophobic state. Fluorescence assays showed that the nonpolar adsorption property of PDMS was significantly decreased. The EOF mobility obtained was 3.6 × 10 −4 cm 2 V −1 s −1 , higher than the typical values found for native PDMS. Due to the better wettability promoted by the modification, the filling of the microchannels with aqueous solutions was facilitated and trapping of air bubbles was not observed.