Journal ArticleDOI
Kinetics of swelling of gels
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TLDR
In this article, a theory of the kinetics of the swelling of polyacrylamide gels is presented, which is based on the assumption that the swelling time is determined by the diffusion coefficient of the fluid molecules.Abstract:
We present a theory of the kinetics of the swelling of a gel. The characteristic time of swelling is proportional to the square of a linear dimension of the gel and is also proportional to the diffusion coefficient of the gel network, which is defined as D=E/f where E is the longitudinal bulk modulus of the network, and f is the coefficient of friction between the network and the gel fluid. This constitutes an essential difference between the present theory and the previous theory which is based on the assumption that the swelling time is determined by the diffusion coefficient of the fluid molecules. Experimental data are shown for spheres of 5% polyacrylamide gels and are analyzed using the present theory. The value of the diffusion coefficient obtained from the macroscopic swelling experiments shows excellent agreement with that obtained microscopically using laser light scattering spectroscopy.read more
Citations
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Journal ArticleDOI
Electrical Deformation of Thermotropic Liquid-Crystalline Polymer Gels
TL;DR: In this paper, a liquid-crystalline elastomer carrying cyanobiphenyl side groups was synthesized by radical copolymerization of 6-(4′-cyanobiphensyl-4-yloxy)hexyl acrylate and hexamethylene diacrylate.
Journal ArticleDOI
Synthesis and characterization of modified carrageenan microparticles for the removal of pharmaceuticals from aqueous solutions.
Stavroula Nanaki,George Z. Kyzas,Areti Tzereme,Myrsini Papageorgiou,Margaritis Kostoglou,Dimitrios N. Bikiaris,Dimitra A. Lambropoulou +6 more
TL;DR: In the present study, carrageenan microparticles were synthesized using spray-drying method and used as biosorbents for the removal of pharmaceutical compounds and it was found that the adsorption isotherms agree well with the Langmuir-Freundlich model.
Journal ArticleDOI
Swelling and mechanical properties of polymer gels with cross-linking gradient
TL;DR: In this paper, a novel approach to model the temperature dependence of the volume and elastic modulus of polymer gels with a cross-linking gradient based on the well-known Flory-Rehner (FR) theory is presented.
Journal ArticleDOI
Microfluidic fabrication of highly stretchable and fast electro-responsive graphene oxide/polyacrylamide/alginate hydrogel fibers
TL;DR: In this paper, the properties, swelling properties and electro-responsive behaviors of the nanocomposite hydrogel fibers were investigated, and the results showed that the highly stretchable and fast electroresponsive hydrogels could be very stretchable by adjusting GO and N,N-methylenebisacrylamide (BIS) contents.
Book ChapterDOI
Hydrogels for Actuators
TL;DR: The first hydrogel-based highly integrated microsystem, a high-resolution tactile display containing 4,225 individually controllable actuator pixels, is reviewed and the basic principles applied on an electronic control forhydrogel actuators and also on the basic components for microfluidics: microvalve, micropump and hydrodynamic transistors.
References
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Journal ArticleDOI
Statistical-Mechanical Theory of Irreversible Processes : I. General Theory and Simple Applications to Magnetic and Conduction Problems
TL;DR: In this paper, a general type of fluctuation-dissipation theorem is discussed to show that the physical quantities such as complex susceptibility of magnetic or electric polarization and complex conductivity for electric conduction are rigorously expressed in terms of timefluctuation of dynamical variables associated with such irreversible processes.
Journal ArticleDOI
Spectrum of light scattered from a viscoelastic gel
TL;DR: In this paper, the spectrum of light scattered from thermally excited displacement fluctuations in polyacrylamide gels was measured using optical mixing spectroscopy, and the correlation function for the displacements having wave vector q is predicted for these gels to have the form of an exponential decay: exp(− Γt).
Journal ArticleDOI
An Introduction to the Theory of Elasticity
P. G. Appleby,R. J. Atkin,N. Fox +2 more