Modular Synthesis and Patterning of High-Stiffness Networks by Postpolymerization Functionalization with Iron-Catechol Complexes

Declan P. Shannon, Joshua D. Moon, Christopher W. Barney, Nairiti J. Sinha, Kai Chieh Yang, Seamus D. Jones, Ronnie V. Garcia, Matthew E. Helgeson, Rachel A. Segalman, Megan T. Valentine, Craig J. Hawker

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Bioinspired iron-catechol cross-links have shown remarkable success in increasing the mechanical properties of polymer networks, in part due to clustering of Fe3+-catechol domains which act as secondary network reinforcing sites. We report a versatile synthetic procedure to prepare modular PEG-acrylate networks with independently tunable covalent bis(acrylate) and supramolecular Fe3+-catechol cross-linking. Initial control of network structure is achieved through radical polymerization and cross-linking, followed by postpolymerization incorporation of catechol units via quantitative active ester chemistry and subsequent complexation with iron salts. By tuning the ratio of each building block, dual cross-linked networks reinforced by clustered iron-catechol domains are prepared and exhibit a wide range of properties (Young’s moduli up to ∼245 MPa), well beyond the values achieved through purely covalent cross-linking. This stepwise approach to mixed covalent and metal-ligand cross-linked networks also permits local patterning of PEG-based films through masking techniques forming distinct hard, soft, and gradient regions.

Original languageEnglish (US)
Pages (from-to)2268-2276
Number of pages9
Issue number6
StatePublished - Mar 28 2023

All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

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