Issue 9, 2016

Multi-responsive nanocomposite hydrogels with high strength and toughness

Abstract

Multi-responsive hydrogels with high strength have great significance for potential applications in smart soft devices. However, it remains a challenge to incorporate multiple responsive moieties with energy dissipation mechanisms. Herein, multi-responsive nanocomposite hydrogels with high compressive strength and toughness were synthesized via in situ copolymerization of N-isopropylacrylamide (NIPAM) and acryloyloxyethyltrimethyl ammonium chloride (DAC) in an aqueous dispersion of exfoliated LAPONITE® RDS with a minute amount of N,N′-methylenebisacrylamide (MBAA) as a crosslinker. The combined use of clay and MBAA is demonstrated to be favorable for the high strength and toughness, and helped in avoiding precipitation of clay nanosheets, which otherwise occurred upon addition of cationic DAC. The effect of the NIPAM/DAC molar ratio, MBAA and clay contents on the properties of the hydrogels has been systematically investigated. Compression tests showed a compressive strength up to 6.2 MPa, with fracture strain higher than 90%. The presence of ionic DAC moieties in the hydrogels rendered a very high swelling ratio up to 40 (g g−1). These hydrogels were responsive to temperature changes due to the presence of NIPAM units, with the transition temperature (Ttrans) dependent on the molar ratio of NIPAM and DAC monomers. The internal electrostatic repulsion of the NIPAM/DAC copolymer network changed upon exposure to solutions with different pH and/or ion strength. Cyclic swelling–shrinking was demonstrated by shuttling the gels between pure water and 0.1 mol L−1 NaCl solution.

Graphical abstract: Multi-responsive nanocomposite hydrogels with high strength and toughness

Associated articles

Supplementary files

Article information

Article type
Paper
Submitted
16 Jan 2016
Accepted
03 Feb 2016
First published
04 Feb 2016

J. Mater. Chem. B, 2016,4, 1733-1739

Multi-responsive nanocomposite hydrogels with high strength and toughness

J. Yang, S. Liu, Y. Xiao, G. Gao, Y. Sun, Q. Guo, J. Wu and J. Fu, J. Mater. Chem. B, 2016, 4, 1733 DOI: 10.1039/C6TB00135A

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