Surface tension evolution during early stages of drying of sol-gel coatings

Dunbar P Birnie, David M. Kaz, Douglas J. Taylor

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Striation defects in spin-coated thin films have been blamed on unfavorable capillary forces that occur due to solvent evaporation commonly experienced during coating deposition. Solvent evaporation during spinning causes predictable composition changes at the surface and these can either stabilize or de-stabilize the surface with respect to convective motions within the coating solution. The present work examines the surface tension changes while adding the most volatile component rather than removing it. This is then a "reverse drying" process, but it provides us with the slope of the surface tension change during normal coating drying. We have examined coating solutions for a case where a specific solvent addition has previously been shown to prevent the formation of striation defects. By measuring both the starting solution (one that produces bad striation defects) and the co-solvent-modified solution (that produces much flatter coatings), we are able to demonstrate the correlation between surface tension changes during spinning and the striation defect formation (or prevention). For the present case, an aluminum-titanate sol-gel recipe, the solvent that eliminated the striation defects is also responsible for a continuous, gradual, reduction in surface tension during the spin-on process, consistent with a model proposed earlier (D. P. Birnie, J Mater Res 16:1145-1154, 2001).

Original languageEnglish
Pages (from-to)233-237
Number of pages5
JournalJournal of Sol-Gel Science and Technology
Volume49
Issue number2
DOIs
Publication statusPublished - Feb 2009

Fingerprint

striation
drying
Sol-gels
Surface tension
Drying
interfacial tension
gels
coatings
Coatings
Defects
defects
coating
metal spinning
Evaporation
evaporation
Aluminum
slopes
aluminum
Thin films
causes

Keywords

  • Drying
  • Marangoni effect
  • Sol-gel
  • Spin coating
  • Surface tension

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Biomaterials
  • Ceramics and Composites
  • Electronic, Optical and Magnetic Materials
  • Materials Chemistry

Cite this

Surface tension evolution during early stages of drying of sol-gel coatings. / Birnie, Dunbar P; Kaz, David M.; Taylor, Douglas J.

In: Journal of Sol-Gel Science and Technology, Vol. 49, No. 2, 02.2009, p. 233-237.

Research output: Contribution to journalArticle

@article{625ca4bbebf847628788f9d3b916761c,
title = "Surface tension evolution during early stages of drying of sol-gel coatings",
abstract = "Striation defects in spin-coated thin films have been blamed on unfavorable capillary forces that occur due to solvent evaporation commonly experienced during coating deposition. Solvent evaporation during spinning causes predictable composition changes at the surface and these can either stabilize or de-stabilize the surface with respect to convective motions within the coating solution. The present work examines the surface tension changes while adding the most volatile component rather than removing it. This is then a {"}reverse drying{"} process, but it provides us with the slope of the surface tension change during normal coating drying. We have examined coating solutions for a case where a specific solvent addition has previously been shown to prevent the formation of striation defects. By measuring both the starting solution (one that produces bad striation defects) and the co-solvent-modified solution (that produces much flatter coatings), we are able to demonstrate the correlation between surface tension changes during spinning and the striation defect formation (or prevention). For the present case, an aluminum-titanate sol-gel recipe, the solvent that eliminated the striation defects is also responsible for a continuous, gradual, reduction in surface tension during the spin-on process, consistent with a model proposed earlier (D. P. Birnie, J Mater Res 16:1145-1154, 2001).",
keywords = "Drying, Marangoni effect, Sol-gel, Spin coating, Surface tension",
author = "Birnie, {Dunbar P} and Kaz, {David M.} and Taylor, {Douglas J.}",
year = "2009",
month = "2",
doi = "10.1007/s10971-008-1849-2",
language = "English",
volume = "49",
pages = "233--237",
journal = "Journal of Sol-Gel Science and Technology",
issn = "0928-0707",
publisher = "Springer Netherlands",
number = "2",

}

TY - JOUR

T1 - Surface tension evolution during early stages of drying of sol-gel coatings

AU - Birnie, Dunbar P

AU - Kaz, David M.

AU - Taylor, Douglas J.

PY - 2009/2

Y1 - 2009/2

N2 - Striation defects in spin-coated thin films have been blamed on unfavorable capillary forces that occur due to solvent evaporation commonly experienced during coating deposition. Solvent evaporation during spinning causes predictable composition changes at the surface and these can either stabilize or de-stabilize the surface with respect to convective motions within the coating solution. The present work examines the surface tension changes while adding the most volatile component rather than removing it. This is then a "reverse drying" process, but it provides us with the slope of the surface tension change during normal coating drying. We have examined coating solutions for a case where a specific solvent addition has previously been shown to prevent the formation of striation defects. By measuring both the starting solution (one that produces bad striation defects) and the co-solvent-modified solution (that produces much flatter coatings), we are able to demonstrate the correlation between surface tension changes during spinning and the striation defect formation (or prevention). For the present case, an aluminum-titanate sol-gel recipe, the solvent that eliminated the striation defects is also responsible for a continuous, gradual, reduction in surface tension during the spin-on process, consistent with a model proposed earlier (D. P. Birnie, J Mater Res 16:1145-1154, 2001).

AB - Striation defects in spin-coated thin films have been blamed on unfavorable capillary forces that occur due to solvent evaporation commonly experienced during coating deposition. Solvent evaporation during spinning causes predictable composition changes at the surface and these can either stabilize or de-stabilize the surface with respect to convective motions within the coating solution. The present work examines the surface tension changes while adding the most volatile component rather than removing it. This is then a "reverse drying" process, but it provides us with the slope of the surface tension change during normal coating drying. We have examined coating solutions for a case where a specific solvent addition has previously been shown to prevent the formation of striation defects. By measuring both the starting solution (one that produces bad striation defects) and the co-solvent-modified solution (that produces much flatter coatings), we are able to demonstrate the correlation between surface tension changes during spinning and the striation defect formation (or prevention). For the present case, an aluminum-titanate sol-gel recipe, the solvent that eliminated the striation defects is also responsible for a continuous, gradual, reduction in surface tension during the spin-on process, consistent with a model proposed earlier (D. P. Birnie, J Mater Res 16:1145-1154, 2001).

KW - Drying

KW - Marangoni effect

KW - Sol-gel

KW - Spin coating

KW - Surface tension

UR - http://www.scopus.com/inward/record.url?scp=58149512308&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=58149512308&partnerID=8YFLogxK

U2 - 10.1007/s10971-008-1849-2

DO - 10.1007/s10971-008-1849-2

M3 - Article

AN - SCOPUS:58149512308

VL - 49

SP - 233

EP - 237

JO - Journal of Sol-Gel Science and Technology

JF - Journal of Sol-Gel Science and Technology

SN - 0928-0707

IS - 2

ER -