Morphological analysis of crease patterns formed on surface-attached hydrogel with a gradient in thickness

• Published in: Journal of applied polymer science 2014-07, Vol.131 (13), p.np-n/a
• Main Author: Kim, Jungwook
• Format: Article
• Language: English
• Subjects: Applied sciences; Creasing; crosslinking; Exact sciences and technology; gels; Hydrogels; Materials science; Microscopy; Morphology; Organic polymers; Physicochemistry of polymers; Polyelectrolytes; Polymers; Power law; Properties and characterization; Self-similarity; Solution and gel properties; stimuli-sensitive polymers; Swelling
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.40482

ABSTRACT The morphology of crease pattern formed on the surface‐attached hydrogel with a gradient in thickness is analyzed. We label the hydrogel surface at the creased state with fluorescent polyelectrolyte, which enables us to visualize surface morphology of creases using the fluorescent microscopy. Various morphological features of crease patterns are analyzed at different thickness of hydrogel, or characteristic spacing of creases λc,max, to examine the self‐similarity of crease morphology at different length scales. Some morphological features show no λc,max dependence, implying the self‐similarity, while others show weak λc,max dependence with positive values of the exponent of power law fit for the plots. We infer that such nonself‐similarity is originated from the variations in the kinetics of swelling and creasing of hydrogel, the effect of surface tension, or the reduction in the osmotic pressure occurred during the polyelectrolyte labeling step at different λc,max. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40482.