2003/05/20 by Hyun Joon Kong, Emma Wong, David J. Mooney +1 · 216 citations
Biochemistry, Genetics and Molecular Biology · Chemistry · Engineering · #Advanced Materials and Mechanics #Advanced Sensor and Energy Harvesting Materials #Brittleness #Chemical engineering #Chemistry #Composite material #Covalent bond #Hydrogels: synthesis, properties, applications #Ion #Ionic bonding #Materials science #Organic chemistry #Polymer chemistry #Self-healing hydrogels #Shear modulus #Toughness
paper · doi:10.1021/ma034137w
published in Macromolecules 36(12), 4582-4588 (American Chemical Society)
openalex publication_date 2003/05/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Refined control over the mechanical properties of hydrogel-based materials has increased as these materials have found broader application. We investigated various aspects of gel cross-linking to independently regulate the elastic modulus ( E ) and toughness ( W ). Alginate hydrogels were chosen as a model system, since alginate can be gelled via ionic or covalent cross-linking, and its block structure dictates the structure of ionic cross-links. Increasing the density of covalent cross-links increased E but led to more brittle gels. In contrast, increasing the density of ionic cross-links and length of the blocks responsible for the cross-linking increased both E and W . Oscillatory shear measurements suggested that ionic cross-links and their length were important in dissipating the energy of deformation due to a partial and stepwise de-cross-linking. In contrast, covalently cross-linked gels underwent energy accumulation. This study demonstrates a novel approach to independently control different mechanical properties of gels.