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Characterisation of polymeric materials as passivation layer for calorimetric H 2 O 2 gas sensors
Author(s) -
Kirchner Patrick,
Reisert Steffen,
Pütz Patrick,
Keusgen Michael,
Schöning Michael J.
Publication year - 2012
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201100773
Subject(s) - passivation , materials science , photoresist , layer (electronics) , absorption (acoustics) , chemical engineering , inert gas , spin coating , coating , surface layer , agglomerate , analytical chemistry (journal) , chemistry , nanotechnology , organic chemistry , composite material , engineering
Calorimetric gas sensors for monitoring the H 2 O 2 concentration at elevated temperatures in industrial sterilisation processes have been presented in previous works. These sensors are built up in form of a differential set‐up of a catalytically active and passive temperature‐sensitive structure. Although, various types of catalytically active dispersions have been studied, the passivation layer has to be established and therefore, chemically as well as physically characterised. In the present work, fluorinated ethylene propylene (FEP), perfluoralkoxy (PFA) and epoxy‐based SU‐8 photoresist as temperature‐stable polymeric materials have been investigated for sensor passivation in terms of their chemical inertness against H 2 O 2 , their hygroscopic properties as well as their morphology. The polymeric materials were deposited via spin‐coating on the temperature‐sensitive structure, wherein spin‐coated FEP and PFA show slight agglomerates. However, they possess a low absorption of humidity due to their hydrophobic surface, whereas the SU‐8 layer has a closed surface but shows a slightly higher absorption of water. All of them were inert against gaseous H 2 O 2 during the characterisation in H 2 O 2 atmosphere that demonstrates their suitability as passivation layer for calorimetric H 2 O 2 gas sensors.