Hydrogels have applications in surgery and drug delivery, but are never considered alongside polymers and composites as materials for mechanical design. This is because synthetic hydrogels are in general very weak. In contrast, many biological gel composites, such as cartilage, are quite strong, and function as tough, shock-absorbing structural solids. The recent development of strong hydrogels suggests that it may be possible to design new families of strong gels that would allow the design of soft biomimetic machines, which have not previously been possible.

Hydrogels for Soft Machines

Polymer solid electrolytes - an overview

The production of poly-(γ-glutamic acid) from microorganisms and its various applications

The review summarizes current trends and developments in the polymerization of alkylene oxides in the last two decades since 1995, with a particular focus on the most important epoxide monomers ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO). Classical synthetic pathways, i.e., anionic polymerization, coordination polymerization, and cationic polymerization of epoxides (oxiranes), are briefly reviewed. The main focus of the review lies on more recent and in some cases metal-free methods for epoxide polymerization, i.e., the activated monomer strategy, the use of organocatalysts, such as N-heterocyclic carbenes (NHCs) and N-heterocyclic olefins (NHOs) as well as phosphazene bases. In addition, the commercially relevant double-metal cyanide (DMC) catalyst systems are discussed. Besides the synthetic progress, new types of multifunctional linear PEG (mf-PEG) and PPO structures accessible by copolymerization of EO or PO with functional epoxide comonomers are presented as well as complex bra...

Polymerization of Ethylene Oxide, Propylene Oxide, and Other Alkylene Oxides: Synthesis, Novel Polymer Architectures, and Bioconjugation.

Hydrogel Adhesion: A Supramolecular Synergy of Chemistry, Topology, and Mechanics

An approach to the quantitative description of superabsorbent polymer hydrogels is examplified by partially hydrolyzed polyacrylamide gels obtained by three-dimensional radical copolymerization or radiation cross-linking of the polymer. The modified swelling theory has been used to develop a system of experimental and computational methods for the evaluation of the supergels network parameters. The possibility of applying these methods to the analysis of the network formation process is also discussed.

Comprehensive characterization of superabsorbent polymer hydrogels

Method of measuring the swelling pressure of superabsorbent gels

Study of solvation of alkali cations with poly(ethylene oxide)

Compressional and shear behaviour of weakly ionic polyacrylamide gels

The elastic modulus of polyacrylamide-acrylic acid hydrogels is studied in a wide range of swelling degrees. The modulus does not follow the concentration dependence predicted by the rubber elasticity theory. At low swelling degrees this can be attributed to the constrained state (non-phantom behaviour) of the network chains. The reason for the increase of modulus at nigh swelling degrees is seen in the finite extensibility and topological entanglements of the chains. A theory including these effects is proposed and verified by experiment.

S.A. Dubrovskii

Papers

Comprehensive characterization of superabsorbent polymer hydrogels

Method of measuring the swelling pressure of superabsorbent gels

Study of solvation of alkali cations with poly(ethylene oxide)

Compressional and shear behaviour of weakly ionic polyacrylamide gels

The elastic behaviour of weakly ionic gels