Journal ArticleDOI
Kinetics of swelling of gels
Reads0
Chats0
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
More filters
Journal ArticleDOI
Interstitial pressure, volume, and flow during infusion into brain tissue.
TL;DR: It is suggested that knowing the distribution of swelling induced by infusion is a prerequisite to describing interstitial transport of solutes.
Journal ArticleDOI
Efficient synthesis of sterically stabilized pH-responsive microgels of controllable particle diameter by emulsion polymerization.
TL;DR: These lightly cross-linked latexes swell significantly faster than P2VP latexes described in the literature and the characteristic time scales observed in the present study are much closer to those predicted by the Tanaka equation.
Journal ArticleDOI
Equilibrium swelling properties of polyampholytic hydrogels
Anthony E. English,S. Mafe,S. Mafe,José A. Manzanares,José A. Manzanares,Xiahong Yu,Alexander Y. Grosberg,Toyoichi Tanaka +7 more
TL;DR: In this article, the role of counter ions and ion dissociation in establishing the equilibrium swelling of balanced and unbalanced polyampholytic hydrogels has been investigated experimentally and theoretically.
Journal ArticleDOI
UV Resonance Raman Determination of Molecular Mechanism of Poly(N-isopropylacrylamide) Volume Phase Transition
TL;DR: Dynamic light scattering, H-NMR, and steady-state and time-resolved UVRR measurements are utilized to determine the molecular mechanism of PNIPAM's hydrophobic collapse and propose the following mechanism for the PnIPAM volume phase transition.
Journal ArticleDOI
Temperature, pH, and Ionic Strength Induced Changes of the Swelling Behavior of PNIPAM−Poly(allylacetic acid) Copolymer Microgels
Matthias Karg,Isabel Pastoriza-Santos,Benito Rodríguez-González,Regine von Klitzing,Stefan Wellert,Thomas Hellweg +5 more
TL;DR: The volume phase transition of colloidal microgels made of N-isopropylacrylamide (NIPAM) is investigated at two different pH values and various salt concentrations to reveal the approximately spherical shape and low polydispersity of the copolymer particles.
References
More filters
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