Institute of Chemical Physics, Russian Academy of Sciences Kosygin Str., 4, 117334 Moscow, RUSSIA
I.I. Oleinik Volgograd State University, Nevskaja Str., 6--115, 400087 Volgograd, RUSSIA
In this talk we shall review the state of the art in polyelectrolyte gel mechanics, electromechanics and physical chemistry for application of polymeric gels as smart materials and structures. Intelligent material systems are of great interest for design of artificial muscles, large motion actuators, sensors, selective pumps, time-controlled drug delivery systems and other adaptive structures. Ionic polymeric gel, three dimensional cross-linked polyelectrolyte network, exhibits unusual macroscopic properties: it reversibly swells or shrinks by changing ionic concentration or pH or applying the electric field. Because of their electromechanical nature, these systems make possible of direct computer control of expansion or contraction and they can convert electrical and chemical energy into mechanical energy.
To realize these applications, the fundamental understanding of underlying processes on microscopic level is of urgent need. We consider in detail the gel thermodynamics, fluctuation effects and phase transitions, the effect of electric field, ion transport. The gel mechanics is described on the grounds of governing equations developed from the microscopic point of view. The microscopic approach includes an application of the theory of polymer networks for the calculation of gels mechanical characteristics and evaluation for the first principles the transport coefficients, elastic constants and other rheological properties.
The main objective of this research is to provide a computational tool based on molecular description for design, modelling and direct computer control of the electrically and/or chemically induced large expansions and contractions of ionic polymeric gels as smart materials and artificial muscles for various novel technological applications.