Kinetics of swelling of polyelectrolyte gels: Fixed degree of ionization

2015 ◽  
Vol 143 (22) ◽  
pp. 224904 ◽  
Author(s):  
Swati Sen ◽  
Arindam Kundagrami
Keyword(s):  
Fixed Degree ◽  
Degree Of Ionization ◽  
Polyelectrolyte Gels ◽  
Kinetics Of ◽  
Kinetics Of Swelling

scholarly journals Polyelectrolyte Gels: A Unique Class of Soft Materials

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 102
Author(s):  
Ferenc Horkay
Keyword(s):  
Exchange Process ◽  
Interaction Strength ◽  
Soft Materials ◽  
Industrial Applications ◽  
Future Research ◽  
Swelling Kinetics ◽  
Polyelectrolyte Gels ◽  
Ion Exchange Process ◽  
Counter Ions ◽  
Kinetics Of

The objective of this article is to introduce the readers to the field of polyelectrolyte gels. These materials are common in living systems and have great importance in many biomedical and industrial applications. In the first part of this paper, we briefly review some characteristic properties of polymer gels with an emphasis on the unique features of this type of soft material. Unsolved problems and possible future research directions are highlighted. In the second part, we focus on the typical behavior of polyelectrolyte gels. Many biological materials (e.g., tissues) are charged (mainly anionic) polyelectrolyte gels. Examples are shown to illustrate the effect of counter-ions on the osmotic swelling behavior and the kinetics of the swelling of model polyelectrolyte gels. These systems exhibit a volume transition as the concentration of higher valence counter-ions is gradually increased in the equilibrium bath. A hierarchy is established in the interaction strength between the cations and charged polymer molecules according to the chemical group to which the ions belong. The swelling kinetics of sodium polyacrylate hydrogels is investigated in NaCl solutions and in solutions containing both NaCl and CaCl2. In the presence of higher valence counter-ions, the swelling/shrinking behavior of these gels is governed by the diffusion of free ions in the swollen network, the ion exchange process and the coexistence of swollen and collapsed states.

The heat of interaction of polyvinylchloride with plasticizers, the kinetics of swelling and phase equilibrium

1983 ◽  
Vol 25 (7) ◽  
pp. 1668-1675 ◽  
Author(s):  
A.A. Tager ◽  
Yu.S. Bessonov ◽  
T.V. Ikanina ◽  
T.A. Rodionova ◽  
A.I. Suvorova ◽  
...  
Keyword(s):  
Phase Equilibrium ◽  
Kinetics Of ◽  
Kinetics Of Swelling

Kinetics of Swelling of Cylindrical Temperature-Responsive Hydrogel: A Semi-Analytical Study

2020 ◽  
Vol 12 (08) ◽  
pp. 2050090
Author(s):  
Amir Hossein Namdar ◽  
Hashem Mazaheri
Keyword(s):  
Chemical Potential ◽  
Water Concentration ◽  
Design Procedures ◽  
Temperature Responsive ◽  
Simple Geometry ◽  
Phase Transition Temperatures ◽  
Link Density ◽  
Cross Link Density ◽  
Kinetics Of ◽  
Kinetics Of Swelling

Cylindrical hydrogels have a wide variety of applications, especially in microfluidics as micro-valves, micro-mixers, and micro-lenses. Main advantages of them can be mentioned as their simple geometry and autonomous functionality due to their responses to the environmental stimuli. In current research, kinetics of swelling, shrinking and force generation of cylindrical temperature-responsive hydrogels have been investigated analytically. According to this, models of fluid permeation and large deformation of the hydrogels were considered and an analytical solution was performed. In order to study the behavior of the cylindrical hydrogels, the temperature is changed between higher and lower of the phase transition temperatures, and kinetics of the swelling and shrinking of the hydrogel have been studied and the distribution of stresses, stretches, water concentration and chemical potential are presented throughout the process. In addition, to investigate the behavior of the actuators, the cylindrical hydrogel is placed inside a hollow permeable pillar and the pressure of the hydrogel which puts on the pillar is studied. Ultimately, a comprehensive study on the effects of different parameters, namely, amount of temperature change, cross-link density and geometry, is conducted and the results are presented, which can be utilized in the design procedures of such actuators.

Kinetics of the conformational transition of poly(methacrylic acid) after changes of its degree of ionization

1985 ◽  
Vol 18 (10) ◽  
pp. 1940-1944 ◽  
Author(s):  
Bohumil Bednar ◽  
Herbert Morawetz ◽  
Jules A. Shafer
Keyword(s):  
Methacrylic Acid ◽  
Conformational Transition ◽  
Degree Of Ionization ◽  
Kinetics Of

Swelling, viscoelastic, and anatomical studies on ionic liquid-swollen Norway spruce as a screening tool toward ionosolv pulping

Holzforschung ◽  
2015 ◽  
Vol 69 (9) ◽  
pp. 1059-1067 ◽  
Author(s):  
Hatem Abushammala ◽  
Jorge F. Pontes ◽  
Gustavo H. Gomes ◽  
Anayancy Osorio-Madrazo ◽  
Rossana M.S.M. Thiré ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Norway Spruce ◽  
Viscoelastic Behavior ◽  
Mechanical Analysis ◽  
Promising Candidate ◽  
Sem Images ◽  
Spruce Wood ◽  
Kinetics Of ◽  
Kinetics Of Swelling

Abstract To screen ionic liquid (IL) candidates for wood ionosolv pulping, swelling and viscoelastic studies on Norway spruce wood treated with ionic liquids have been conducted. In particular, the temperature dependency and kinetics of swelling in 1-butyl-3-methylimidazolium acesulfamate ([BMIM]Ace) and in 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) were in focus. The kinetics of volumetric swelling in [BMIM]Ace yielded an Ea of 54 kJ.mol-1 compared to 23 kJ.mol-1 in [EMIM]OAc. The viscoelastic behavior of IL-swollen wood was studied by dynamic mechanical analysis, and the lowest in situ glass transition temperature (Tg) of lignin was ∼58°C and ∼65°C in [BMIM]Ace and in [EMIM]OAc, respectively. These Tg values are lower than that found in water. Higher Tg was calculated by the Gordon-Taylor equation, which means that swelling is not only due to the plasticizing effect of the ILs. SEM images showed that [EMIM]OAc has a stronger plasticizing effect than [BMIM]Ace. Overall, [EMIM]OAc is the most efficient agent for wood swelling, softening, and disintegration and, thus, it is the most promising candidate for ionosolv pulping.

Sign in / Sign up

Export Citation Format

Share Document