High-water-content hydrogels exhibiting superior stiffness, strength, and toughness. (May 2020)

• Record Type: Journal Article
• Authors: Tran, Van Tron; Mredha, Md. Tariful Islam; Jeon, Insu
• Is Part Of: Extreme mechanics letters. Volume 37(2020)
• Publication Date: 2020-05
• Subjects: AAI 5-acrylamidoisophthalic acid -- AAm Acrylamide -- PIC Polyion-complex -- DMSO Dimethyl sulfoxide -- AIBN 2, 2-azobisisobutyronitrile -- NaOH Sodium hydroxide -- HCl Hydrochloric acid -- PA Phenyl acrylate -- NMR Nuclear magnetic resonance -- Γ Fracture energy -- Lc Critical length -- SEM Scanning electron microscopy -- DSC Differential scanning calorimetry; Amphiphilic monomer -- Hydrophilic monomer -- Hydrophobic–hydrophilic hydrogel -- Stiffness -- Strength -- Toughness; Mechanics -- Periodicals; Mechanics, Applied -- Periodicals; Mechanics; Electronic journals; Periodicals; 531.05
• DOI: 10.1016/j.eml.2020.100691
• Languages: English
• ISSNs: 2352-4316

Abstract

Abstract: The low mechanical properties of high-water-content hydrogels often hinder their broad use in biomedical applications, especially in replacing/treating load-bearing tissues. Inspired by the protein structure of load-bearing tissues, we developed high-water-content hydrogels with excellent mechanical properties using a hydrophobic–hydrophilic copolymer strategy employing a benzene-based amphiphilic monomer, 5-acrylamidoisophthalic acid (AAI), as the major hydrophobic component and acrylamide (AAm) as the major hydrophilic component. The AAI monomer, connected with two –COOH functional groups, allowed the hydrogel to absorb excess water via H-bonding without compromising its homogeneity and structure. The AAI-rich hard-phase regions (via benzene–benzene interactions and hydrophobic associations) and AAm-rich soft-phase regions resulted in the high-water-content ( ∼ 80 wt%) hydrogel exhibiting a combination of good mechanical properties. Graphical abstract: Highlights: High-water-content hydrogels with excellent mechanical properties were developed. A hydrophobic–hydrophilic copolymer-based strategy was adopted for the synthesis of robust hydrogels. 5-acrylamidoisophthalic acid monomers with two –COOH functional groups were employed as the hydrophobic component. Acrylamide monomers were employed as the hydrophilic component. The hydrogels were very stiff, strong, and tough, maintaining a high water content.