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.

Kinetics of ion exchange process for separation of glutamic acid

1989 ◽  
Vol 4 (6) ◽  
pp. 249-256 ◽  
Author(s):  
T. H. �zdamar ◽  
S. Taka� ◽  
G. �alik ◽  
R. Ballica
Keyword(s):  
Ion Exchange ◽  
Glutamic Acid ◽  
Exchange Process ◽  
Ion Exchange Process ◽  
Kinetics Of ◽  
Kinetics Of Ion Exchange

Zur Kinetik der Ionenaustauscher III. Die Filmdiffusion bei vollständigen Umbeladungen

1969 ◽  
Vol 24 (6) ◽  
pp. 900-902
Author(s):  
Kurt Bunzel
Keyword(s):  
Ion Exchange ◽  
Exchange Reaction ◽  
Exchange Process ◽  
Ionic Composition ◽  
Selectivity Coefficient ◽  
Film Diffusion ◽  
Ion Exchange Process ◽  
Ion Exchange Reaction ◽  
Diffusion Controlled ◽  
Kinetics Of

The selectivity coefficient K21 of an ion-exchange process is in general a function of the ionic composition of the material. As a result, the value of K21 will change continuously during a com­plete conversion of the ion-exchanger. Equations for the kinetics of such a conversion with variable K21 are given for a film diffusion controlled ion-exchange reaction.

Synthesis of linear alkylbenzene sulphonate intercalated iron(II) iron(III) hydroxide sulphate (green rust) and adsorption of carbon tetrachloride

Clay Minerals ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 307-317 ◽  
Author(s):  
K. B. Ayala-Luis ◽  
D. K. Kaldor ◽  
C. Bender Koch ◽  
B. W. Strobel ◽  
H. C. B. Hansen
Keyword(s):  
Carbon Tetrachloride ◽  
Ion Exchange ◽  
Exchange Process ◽  
Green Rust ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
Linear Alkylbenzene ◽  
Ion Exchange Process ◽  
Linear Alkylbenzene Sulphonate ◽  
Kinetics Of

AbstractGreen rusts, GRs, can act as both sorbents and reductants towards selected pollutants. Organo-GRs are expected to combine these properties with a high affinity for hydrophobic substances. A novel organo-GR, GRLAS, was synthesized by incorporating a mixture of linear alkylbenzenesulphonates (LAS) into the interlayer space of synthetic sulphate green rust, GRSO4 . Mössbauer analysis of GRLAS indicates that the structure of the organo-GR is very similar to that of the initial GRSO4 with regard to the FeII/FeIII ratio and local coordination of Fe atoms. X-ray diffraction demonstrates that the GRLAS formed was well ordered, although a mixture of surfactant was used for intercalation. The basal spacings of the GRLAS and the kinetics of the ion-exchange process were dependent on the initial surfactant loading; basal spacings of ~2.85 nm were obtained at LAS solution concentrations >10 mM. The ratio LASadsorbed/SO42–desorbed significantly exceeded the stoichiometric ratio of 2 during the initial part of the ion-exchange process (t = 5 h). However, this ratio was reached progressively with time. GRSO4 preferentially sorbed LAS homologues with long alkyl chains over short ones. Carbon tetrachloride was successfully adsorbed into GRLAS. The adsorption isotherm was linear with a distribution coefficient, Kd, of 505±19 litre kg–1.

scholarly journals Understanding the Ion Exchange Process in LDH Nanomaterials by Fast In Situ XRPD and PCA-Assisted Kinetic Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Luca Palin ◽  
Marco Milanesio ◽  
Wouter van Beek ◽  
Eleonora Conterosito
Keyword(s):  
Environmental Chemistry ◽  
Exchange Process ◽  
Ion Exchange Process ◽  
Anionic Clays ◽  
Interlayer Anion ◽  
Double Hydroxides ◽  
Kinetics Of ◽  
Positively Charged ◽  
Xrpd Pattern

Layered double hydroxides (LDHs) are nanomaterials with interesting properties finding applications in many fields, such as catalysis, environmental chemistry, and pharmaceuticals. They are anionic clays with positively charged layers and anions within the layers to reach neutrality. Their properties are defined by both composition and morphology. The composition can be tuned by exchanging the interlayer anion. The far more stable, common, and highly prevalent among natural LDHs is the carbonate anion thanks to its double negative charge. To adapt the properties of LDHs for technological applications, the challenge is to exchange the carbonate with the functionalizing monovalent anions in an effective and cheap way. In this study, the exchange of carbonate with nitrate ions is studied by in situ X-ray powder diffraction (XRPD). The exchange is carried out by a liquid-assisted grinding approach, inserting the mechanically ground dry sample in a capillary and then wetting it with a drop of nitric acid, while measuring the XRPD pattern. The kinetics of the process was investigated by the Avrami-Erofe’ev method; the reaction mechanism was determined using the advancing interface model and by analyzing the XRD peak shapes, which evidentiate changes in the crystallinity during the reaction. The reaction starts from the faces perpendicular to the layers and occurs along the channels, increasingly limited by diffusion when approaching the internal part of the crystals.

An ion-exchange process with thermal regeneration. VI. Factors influencing the titration curve shape of weak electrolyte resins

1968 ◽  
Vol 21 (11) ◽  
pp. 2703 ◽  
Author(s):  
BA Bolto ◽  
R McNeill ◽  
AS MacPherson ◽  
R Siudak ◽  
DE Weiss ◽  
...  
Keyword(s):  
Titration Curve ◽  
Exchange Process ◽  
Ion Pairs ◽  
Curve Shape ◽  
Thermal Regeneration ◽  
Weak Electrolyte ◽  
Ion Exchange Process ◽  
Titration Curves ◽  
Counter Ions ◽  
Primary Amino

An experimental study is presented which establishes that if the titration curve of a weak electrolyte resin is to exhibit a well-defined pH plateau, it must have a structure which is homofunctional and which is not too polar. Homofunctional mono- and di-alkylamino groups in a cross-linked hydrocarbon polymeric structure exhibit such a plateau. Polymers with non-polar backbones and primary amino or carboxyl groups possess sloping titration curves. The results can be accounted for by the formation of ion pairs with monovalent counter ions in the less polar structures, or with multivalent counter ions in more polar structures.

scholarly journals History, Introduction, and Kinetics of Ion Exchange Materials

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Sanjeev Kumar ◽  
Sapna Jain
Keyword(s):  
Ion Exchange ◽  
Exchange Process ◽  
Paper Briefly ◽  
Factors Affecting ◽  
Controlled Diffusion ◽  
Ion Exchange Process ◽  
History Of ◽  
Laboratory Tool ◽  
Kinetics Of ◽  
Kinetics Of Ion Exchange

During the last few decades, ion exchange materials have evolved from laboratory tool to industrial products with significant technical and commercial impact. The current paper briefly summarizes the history of the development of the ion exchange materials. The paper defines the ion exchange materials and their types. The paper signifies the kinetics involved in the ion exchange process with description of factors affecting the rate of ion exchange. The mechanism of ion exchange has also been delineated through schematic diagram, illustrating that there are two types of diffusion, film and particle controlled diffusion. A brief of mathematical approach for kinetics of ion exchange has also been incorporated.

Determination of the ion exchange process of K2Ti4O9 fibers at constant pH and modeling with statistical rate theory

RSC Advances ◽  
2015 ◽  
Vol 5 (90) ◽  
pp. 73474-73480 ◽  
Author(s):  
Chang Liu ◽  
Nanhua Wu ◽  
Jun Wang ◽  
Liangliang Huang ◽  
Xiaohua Lu
Keyword(s):  
Ion Exchange ◽  
Exchange Process ◽  
Rate Theory ◽  
Ion Exchange Process ◽  
Statistical Rate Theory ◽  
Constant Ph ◽  
Ion Exchange Kinetics ◽  
Exchange Kinetics ◽  
Kinetics Of

The ion exchange kinetics of K2Ti4O9 fibers at constant pH was determined precisely by ion-selective electrodes, and activity coefficients of ions in solutions were calculated by the Lu–Maurer equation.

scholarly journals Buffer effects on aqueous swelling kinetics of polyelectrolyte gels

1992 ◽  
Vol 45 (8) ◽  
pp. 1411-1423 ◽  
Author(s):  
Loretta Y. Chou ◽  
Harvey W. Blanch ◽  
John M. Prausnitz ◽  
Ronald A. Siegel
Keyword(s):  
Swelling Kinetics ◽  
Polyelectrolyte Gels ◽  
Kinetics Of ◽  
Buffer Effects
Sign in / Sign up

Export Citation Format

Share Document