Issue 11, 2014

Tough nanocomposite double network hydrogels reinforced with clay nanorods through covalent bonding and reversible chain adsorption

Abstract

Polymer hydrogels with superior strength and toughness are potential candidate materials for the replacement or engineering of load-bearing tissues. This manuscript reports novel tough nanocomposite hydrogels with an unusual energy dissipation mechanism based on both covalent and physical interactions between clay nanorods and polymer chains. Attapulgite (ATP) nanorods grafted with vinyl groups on the surface served as macro-crosslinkers to copolymerize with 2-acrylamido-2-methylpropane-sulfonic acid (AMPS) to form an initial nanocomposite network, which subsequently hosted the polymerization of acrylamide (AAm) monomers to generate a novel nanocomposite double network (DN) hydrogel. The morphology, swelling behavior and compressive properties of the ATP-grafted DN hydrogels were investigated as a function of ATP content (CATP), in comparison with the ATP-filled DN gels. With a clay content between 0.1 wt% and 1.0 wt%, the nanocomposite hydrogels did not fracture up to a compressive strain of 98%, exhibiting an initial modulus (E) up to 0.36 MPa, a compressive strength higher than 65.7 MPa, and a work to fracture (or fracture energy) higher than 2.6 MJ m−3, in comparison to 0.19 MPa, 18.6 MPa, and 1.1 MJ m−3 for the conventional DN gels. Cyclic loading–unloading tests showed abnormal residual energy dissipation even though the rigid PAMPS network had fractured. Such viscous energy dissipation decayed during cyclic loading, and could be restored depending on time and temperature. This is related to the reversible desorption–re-adsorption of polymer chains from the clay surface. Possible reinforcing and fracture mechanisms are discussed.

Graphical abstract: Tough nanocomposite double network hydrogels reinforced with clay nanorods through covalent bonding and reversible chain adsorption

Supplementary files

Article information

Article type
Paper
Submitted
04 Nov 2013
Accepted
12 Dec 2013
First published
13 Dec 2013

J. Mater. Chem. B, 2014,2, 1539-1548

Tough nanocomposite double network hydrogels reinforced with clay nanorods through covalent bonding and reversible chain adsorption

G. Gao, G. Du, Y. Cheng and J. Fu, J. Mater. Chem. B, 2014, 2, 1539 DOI: 10.1039/C3TB21554G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements