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Study of hydrophilicity and stability of chemically modified PDMS surface using piranha and KOH solution
Author(s) -
Maji Debashis,
Lahiri S. K.,
Das Soumen
Publication year - 2012
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.3770
Subject(s) - contact angle , hydrophilization , materials science , surface modification , elastomer , chemical engineering , chemical modification , adhesion , fourier transform infrared spectroscopy , surface energy , chemical stability , surface tension , composite material , polymer chemistry , engineering , physics , quantum mechanics
Successful realization of various BioMEMS devices demands effective surface modification techniques of PDMS elastomer. This paper presents a detailed report on a simple and cost effective approach for surface modification of PDMS films involving wet chemical treatment in two‐step processes: primarily involving piranha solution followed by KOH dip to improve hydrophilicity and stability of PDMS surface. Chemical composition of the solution and surface treatment condition have been varied and optimized to significantly increase the surface energy. The effect of surface modification of the elastomer after wet chemical treatment is analyzed using contact angle measurement and FTIR‐ATR study. PDMS surface treated in piranha solution with H 2 O 2 and H 2 SO 4 in the ratio of 2:3 followed by a dip in KOH solution for 15 min duration each, demonstrated a maximum reduction of contact angle to ∼27° as compared to untreated sample having a contact angle of ∼110°. The removal of hydrophobic methyl group from elastomer surface and subsequent hydrophilization of surface by wet chemical process was confirmed from FTIR‐ATR spectra. This result is also supported by improved adhesion and electrical continuity of deposited aluminum metal film over the modified PDMS surface. Copyright © 2011 John Wiley & Sons, Ltd.