Issue 15, 2010

Nano-hybrid self-crosslinked PDMA/silica hydrogels

Abstract

We discovered that the free radical polymerization of N,N-dimethylacrylamide in water can lead, above a certain concentration, to gels without any added difunctional crosslinker. These so called “self-crosslinked” hydrogels were prepared and their weak mechanical properties were improved by introducing silica nanoparticles.

From swelling experiments performed at equilibrium in aqueous media, it was shown that silica particles behave as adhesive fillers and strongly interact with PDMA chains. These interactions are responsible for the reinforcement of mechanical properties. From initial elastic moduli, determined in the preparation state, we show that the elastic behaviour of these hydrogels mainly originates from entanglements and from physical crosslinks that can be controlled by the polymer concentration and the ratio between silica particles and polymer chains, respectively. The mechanical behaviour was characterized using: monotonic tensile tests, loading-unloading cycles at large strains and stress relaxation experiments in order to investigate long time behaviour. The introduction of silica highly increases the stiffness of the network without greatly reducing its extensibility, implying that strong interactions take place between PDMA chains and silica surfaces.

Non-linear behavior was pointed out: softening at small deformations and hardening at high deformations which is related to finite chain extensibility. All these effects have been shown to strongly depend on the silica content. The analysis of hysteresis and residual strains induced by cycles, clearly indicate that contrary to chemical crosslinkers, hybrid interactions increase the dissipative process.

Graphical abstract: Nano-hybrid self-crosslinked PDMA/silica hydrogels

Article information

Article type
Paper
Submitted
19 Feb 2010
Accepted
08 Apr 2010
First published
07 Jun 2010

Soft Matter, 2010,6, 3619-3631

Nano-hybrid self-crosslinked PDMA/silica hydrogels

L. Carlsson, S. Rose, D. Hourdet and A. Marcellan, Soft Matter, 2010, 6, 3619 DOI: 10.1039/C0SM00009D

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