Frontal vitrification of PDMS using air plasma and consequences for surface wrinkling
File(s)Nania_SM_2015.pdf (744.95 KB)
Published version
Author(s)
Nania, M
Matar, OK
Cabral, JT
Type
Journal Article
Abstract
We study the surface oxidation of polydimethylsiloxane (PDMS) by air plasma exposure and its implications for the mechanically-induced surface wrinkling of the resulting glass–elastomer bilayers. The effect of plasma frequency (kHz and MHz), oxygen content (from O2 to air), pressure (0.5 ≤ P ≤ 1.5 mbar), as well as exposure time and power, is quantified in terms of the resulting glassy skin thickness h, inferred from wrinkling experiments. The glassy skin thickness is found to increase logarithmically with an exposure time t, for different induction powers p, and all data collapse in terms of a plasma dose, D ≡ p × t. The kinetics of film propagation are found to increase with the oxygen molar fraction yO2 and decrease with the gas pressure P, allowing both the wrinkling wavelength λ and amplitude A to be effectively controlled by gas pressure and composition. A generalised relationship for frontal vitrification is obtained by re-scaling all λ and h data by D/P. A coarse-grained wave propagation model effectively describes and quantifies the process stages (induction, skin formation and propagation) under all the conditions studied. Equipped with this knowledge, we further expand the capabilities of plasma oxidation for PDMS wrinkling, and a wavelength of λ ≈ 100 nm is readily attained with a modest strain εprestrain ≈ 20%.
Date Issued
2015-02-13
Date Acceptance
2015-02-13
Citation
Soft Matter, 2015, 11 (15), pp.3067-3075
ISSN
1744-6848
Publisher
Royal Society of Chemistry
Start Page
3067
End Page
3075
Journal / Book Title
Soft Matter
Volume
11
Issue
15
Copyright Statement
© The Royal Society of Chemistry 2015. This Open Access Article is licensed under a
Creative Commons Attribution 3.0 Unported Licence
Creative Commons Attribution 3.0 Unported Licence
License URL
Subjects
Science & Technology
Physical Sciences
Technology
Chemistry, Physical
Materials Science, Multidisciplinary
Physics, Multidisciplinary
Polymer Science
Chemistry
Materials Science
Physics
CHEMICAL-VAPOR-DEPOSITION
THIN-FILMS
COMPLIANT SUBSTRATE
ELASTOMERIC POLYMER
ORDERED STRUCTURES
POLYDIMETHYLSILOXANE
NETWORKS
PATTERNS
DEFORMATION
MECHANICS
Publication Status
Published