Stimuli-responsive degrafting of polymer brushes via addressable catecholato-metal attachments. Issue 35 (24th August 2020)

• Record Type: Journal Article
• Authors: Agergaard, Asger Holm; Pedersen, Steen Uttrup; Birkedal, Henrik; Daasbjerg, Kim
• Is Part Of: Polymer chemistry. Volume 11:Issue 35(2020)
• Page Start: 5572
• Page End: 5577
• Publication Date: 2020-08-24
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/d0py00916d
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : Surface attached catecholato-metal complexes serve as polymer brush initiators with well-defined densities and enable stimuli-responsive degrafting of polymer brushes. Abstract : Catecholato-metal complexes are widely used in functional materials such as hydrogels, where the dynamic nature of the coordination bonds between catechol and metal ions contributes to self-healing and stimuli-responsive properties. Herein, we translate the pH-controlled speciation of such complexes known from bulk to a surface counterpart. We create catecholato-metal attachments by electrografting catechol to glassy carbon surfaces, enabling binding of Al 3+ or Fe 3+ and, subsequently, dopamine. When binding dopamine, pH determines whether bis- or tris-catecholato-metal species dominate. Polymer brushes of poly(methyl methacrylate) are grown from these attachments and subsequently detached by electro-oxidation of the catechol, causing the catecholato-metal complex to disintegrate. This study shows that the catecholato-metal complex retains its pH- and oxidation-responsive properties when confined to the surface, and that catechol-based polymer brush interfaces constitute a versatile approach toward on-demand renewal of smart surfaces.