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Lookup NU author(s): Professor Mark GeogheganORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2016 The Royal Society of Chemistry.For environmentally-switchable adhesive systems to be reused repeatedly, the adhesive strength must not deteriorate after each adhesion cycle. An important criterion to achieve this goal is that the integrity of the interface must be retained after each adhesion cycle. Furthermore, in order to have practical benefits, reversing the adhesion must be a relatively rapid process. Here, a double-network hydrogel of poly(methacrylic acid) and poly[oligo(ethylene glycol)methyl ether methacrylate] is shown to undergo adhesive failure during pH-switchable adhesion with a grafted (brush) layer of polycationic poly[2-(diethyl amino)ethyl methacrylate], and can be reused at least seven times. The surfaces are attached at pH 6 and detached at pH 1. A single-network hydrogel of poly(methacrylic acid), also exhibits pH-switchable adhesion with poly[2-(diethyl amino)ethyl methacrylate] but cohesive failure leads to an accumulation of the hydrogel on the brush surface and the hydrogel can only be reused at different parts of that surface. Even without an environmental stimulus (i.e. attaching and detaching at pH 6), the double-network hydrogel can be used up to three times at the same point on the brush surface. The single-network hydrogel cannot be reused under such circumstances. Finally, the time taken for the reuse of the double-network hydrogel is relatively rapid, taking no more than an hour to reverse the adhesion.
Author(s): Alfhaid L, Seddon WD, Williams NH, Geoghegan M
Publication type: Article
Publication status: Published
Journal: Soft Matter
Online publication date: 10/05/2017
Acceptance date: 03/05/2016
Date deposited: 19/12/2019
ISSN (print): 1744-683X
ISSN (electronic): 1744-6848
Publisher: Royal Society of Chemistry
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