Scaling analysis of polyacrylamide gel surfaces synthesized in the presence of surfactants

From National Research Council Canada

DOI	Resolve DOI: https://doi.org/10.1016/S0021-9797(02)00144-3
Author	Search for: Chakrapani, Mukundan; Search for: Mitchell, S. J.; Search for: Van Winkle, D. H.; Search for: Rikvold, P. A.
Format	Text, Article
Subject	Atomic force microscopy (AFM); Complex systems; Percolation transition; Polyacrylamide gels; Scaling analysis; Self-affine scaling; Surfactants
Abstract	Surfaces of polyacrylamide hydrogels synthesized in the presence of surfactants were imaged by atomic force microscopy (AFM), and the surface morphology was studied by numerical scaling analysis. The gels were formed by polymerizing acrylamide plus a cross-linker in the presence of surfactants, which were then removed by soaking in distilled water. Gels formed in the presence of over 20% surfactant (by weight) formed clear, but became opaque upon removal of the surfactants. Other gels formed and remained clear. The surface morphology of the gels was studied by several one- and two-dimensional numerical scaling methods. The surfaces were found to be self-affine on short length scales, with a roughness (Hurst) exponent in the range from 0.85 to 1, crossing over to a constant root-mean-square surface width at long scales. Both the crossover length between these two regimes and the saturation value of the surface width increased significantly with increasing surfactant concentration, coincident with the increase in opacity. We propose that the changes in the surface morphology are due to a percolation transition in the system of voids formed upon removal of the surfactants from the bulk.
Publication date	2003-02-01
In	Journal of Colloid and Interface Science 258, no. 1 (1 February 2003): 186–197.
Language	English
NRC publication	This is a non-NRC publication "Non-NRC publications" are publications authored by NRC employees prior to their employment by NRC.
NPARC number	12328510
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Record identifier	b26041be-ba8a-49ec-bcd2-b6817ff5def4
Record created	2009-09-10
Record modified	2020-04-02

Date modified:: 2024-07-22