Some hydrogels having novel molecular structures

Hydrogels are important materials for a variety of applications, particularly biomedical devices, but they generally have poor mechanical properties since they consist predominantly of water held in place by a relatively fragile polymer network. This brief review describes a few novel methods to control or improve the mechanical properties of hydrogels including slide-ring gels, double-network gels, nanocomposite gels, and photoactive gels. Our goal is to encourage more researchers to be aware of and to exploit these methods. (C) 2009 Elsevier Ltd. All rights reserved.