Exploiting Supramolecular Interactions from Polymeric Colloids for Strong Anisotropic Adhesion between Solid Surfaces

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Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2020-04-01
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Mcode
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Language
en
Pages
Series
Advanced Materials, articlenumber 1906886
Abstract
Adhesion occurs by covalent bonding, as in reactive structural adhesives, or through noncovalent interactions, which are nearly ubiquitous in nature. A classic example of the latter is gecko feet, where hierarchical features enhance friction across the contact area. Biomimicry of such structured adhesion is regularly achieved by top-down lithography, which allows for direction-dependent detachment. However, bottom-up approaches remain elusive given the scarcity of building blocks that yield strong, cohesive, self-assembly across multiple length scales. Herein, an exception is introduced, namely, aqueous dispersions of cellulose nanocrystals (CNCs) that form superstructured, adherent layers between solid surfaces upon confined evaporation-induced self-assembly (C-EISA). The inherently strong CNCs (EA > 140 GPa) align into rigid, nematically ordered lamellae across multiple length scales as a result of the stresses associated with confined evaporation. This long-range order produces remarkable anisotropic adhesive strength when comparing in-plane (≈7 MPa) and out-of-plane (≤0.08 MPa) directions. These adhesive attributes, resulting from self-assembly, substantially outperform previous biomimetic adhesives obtained by top-down microfabrication (dry adhesives, friction driven), and represent a unique fluid (aqueous)-based system with significant anisotropy of adhesion. By using C-EISA, new emergent properties will be closely tied with the nature of colloids and their hierarchical assemblies.
Description
| openaire: EC/H2020/788489/EU//BioELCell
Keywords
adhesion, cellulose, colloids, self-assembly, supramolecular interactions
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Citation
Tardy, B L, Richardson, J J, Greca, L G, Guo, J, Ejima, H & Rojas, O J 2020, ' Exploiting Supramolecular Interactions from Polymeric Colloids for Strong Anisotropic Adhesion between Solid Surfaces ', Advanced Materials, vol. 32, no. 14, 1906886 . https://doi.org/10.1002/adma.201906886