TY - JOUR
T1 - Characterizing the distribution of sodium alkyl sulfate surfactant homologues in water-based, acrylic pressure-sensitive adhesive films
AU - Zhang, Jilin
AU - Severtson, Steve J
AU - Houtman, Carl J.
PY - 2011/6/30
Y1 - 2011/6/30
N2 - The distributions of three sodium alkyl sulfate surfactants in dry adhesive films cast from water-based latexes were characterized using confocal Raman microscopy (CRM) and contact angle (CA) and tack measurements. Sodium dodecyl sulfate (SDS), sodium tetradecyl sulfate (STS), and sodium octadecyl sulfate (SODS) were added to dialyzed commercial adhesive latex at various concentrations. Uneven distributions were found for all three surfactants along with a tendency to enrich film-air interfaces and, to a much lesser extent, film-glass interfaces. SDS demonstrated the greatest tendency to concentrate near film surfaces followed by STS and SODS. For all three surfactants, water CA values for dried films decreased sharply with increasing concentrations in the latex, but significant differences were observed, with SDS again having the greatest impact followed by STS and SODS. Tack of dried polymer films was also found to decrease with increasing latex surfactant levels, with SDS producing the sharpest drop as well as the lowest plateau values. Results indicate that interfacial enrichment by surfactants is detectable via both CRM and CA measurements, and this enrichment can significantly affect the performance of films. Finally, surface enrichment levels are qualitatively related to measures of the surfactants' affinity for aqueous solutions, as characterized by the logarithm of their 1-octanol-water distribution coefficients (Kow).
AB - The distributions of three sodium alkyl sulfate surfactants in dry adhesive films cast from water-based latexes were characterized using confocal Raman microscopy (CRM) and contact angle (CA) and tack measurements. Sodium dodecyl sulfate (SDS), sodium tetradecyl sulfate (STS), and sodium octadecyl sulfate (SODS) were added to dialyzed commercial adhesive latex at various concentrations. Uneven distributions were found for all three surfactants along with a tendency to enrich film-air interfaces and, to a much lesser extent, film-glass interfaces. SDS demonstrated the greatest tendency to concentrate near film surfaces followed by STS and SODS. For all three surfactants, water CA values for dried films decreased sharply with increasing concentrations in the latex, but significant differences were observed, with SDS again having the greatest impact followed by STS and SODS. Tack of dried polymer films was also found to decrease with increasing latex surfactant levels, with SDS producing the sharpest drop as well as the lowest plateau values. Results indicate that interfacial enrichment by surfactants is detectable via both CRM and CA measurements, and this enrichment can significantly affect the performance of films. Finally, surface enrichment levels are qualitatively related to measures of the surfactants' affinity for aqueous solutions, as characterized by the logarithm of their 1-octanol-water distribution coefficients (Kow).
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U2 - 10.1021/jp202731h
DO - 10.1021/jp202731h
M3 - Article
C2 - 21604743
AN - SCOPUS:79959563144
SN - 1520-6106
VL - 115
SP - 8138
EP - 8144
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 25
ER -