Behavior of Polyelectrolyte Gels in Concentrated Solutions of Highly Soluble Salts

MRS Advances ◽  
2020 ◽  
Vol 5 (17) ◽  
pp. 907-915 ◽  
Author(s):  
Jessica L. Sargent ◽  
Xunkai Chen ◽  
Mitchell C. Brezina ◽  
Sebastian Aldwin ◽  
John A. Howarter ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
High Performance Concrete ◽  
Group Versus ◽  
Transition Metal Ions ◽  
Main Group ◽  
Ion Concentration ◽  
Polyelectrolyte Gels ◽  
Counter Ion ◽  
Versus Transition

ABSTRACTIonic hydrogels are an abundant class of materials with applications ranging from drug delivery devices to high performance concrete to baby diapers. A more thorough understanding of interactions between polyelectrolyte networks and ionic solutes is critical as these materials are further tailored for performance applications in highly targeted ionic environments. In this work, we seek to develop structure-property relationships between polyelectrolyte gels and environments containing high concentrations of multivalent ions. Specifically, this work seeks to elucidate the causes behind differences in hydrogel response to divalent ions of main group metals versus transition metals. PANa-co-PAM hydrogels containing low and high fractions of ionic groups are investigated in solutions of DI water, NaCl, CaCl2, and CuSO4 at concentrations ranging from 5 to 100 mM in order to understand 1) the transient or permanent nature of crosslinks produced in these networks by divalent counter-ions, 2) the role of polymer ionic content in these interactions, and 3) how these interactions scale with salt concentration. Gravimetric swelling and mechanical compression testing are employed to characterize water and salt-swollen hydrogels in order to develop guiding principles to control and manipulate material properties through polymer-counter-ion interactions. The work presented here confirms the formation of permanent crosslinks by transition metal ions, offers explanation for the behavioral discrepancy observed between ionic hydrogels and main group versus transition metal ions, and illustrates how such hydrogel properties scale with counter-ion concentration.

scholarly journals Metallo-Supramolecular Hydrogels from the Copolymers of Acrylic Acid and 4-(2,2′:6′,2″-terpyridin-4′-yl)styrene

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1152 ◽  
Author(s):  
Huiqin Zhang ◽  
Pan Liu ◽  
Zheng Chi ◽  
Xuegang Chen
Keyword(s):  
Transition Metal ◽  
Acrylic Acid ◽  
Metal Ions ◽  
Self Assembly ◽  
Wavelength Region ◽  
Transition Metal Ions ◽  
Ion Concentration ◽  
Iron Ions ◽  
Absorption Intensity ◽  
Dilute Aqueous Solution

Hydrophilic copolymers containing 2,2′:6′,2″-terpyridine moieties and acrylic acid (AA) units poly (acrylic acid-co-4-(2,2′:6′,2″-terpyridin-4′-yl)styrene) (P(AA-co-TPY)) were synthesized and characterized. Coordinated with different transition metal ions, the dilute aqueous solution of the copolymers exhibited red-shifted UV-vis absorption peaks of π-π* transition from 317 to 340 nm. Further, interacting with iron ions, the copolymer showed new absorption peaks at a longer wavelength region (570 nm) and the absorption intensity enhanced with increase of the ion concentration. When enough ions were added to coordinate with the 2,2′:6′,2″-terpyridine moieties, novel metallo-supramolecular hydrogels were obtained due to the formation of metal coordination bonds between polymer back bones and transition metal ions (Ni2+, Zn2+, Cd2+, Fe2+ and Cu2+), which acted as self-assembly crosslinking structures. The mechanical strength and morphology of the resulting metallo-supramolecular hydrogels have been investigated.

Anab initiomolecular orbital study comparing the bonding of the NH3and the H2O in the monoammines and the monohydrates of main group and transition metal ions

2003 ◽  
Vol 101 (15) ◽  
pp. 2451-2467 ◽  
Author(s):  
PHILIP GEORGE ◽  
JENNY P. GLUSKER ◽  
GEORGE D. MARKHAM ◽  
MENDEL TRACHTMAN ◽  
CHARLES W. BOCK
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Main Group ◽  
Orbital Study

Coordination compounds of thiabendazole with main group and transition metal ions

2002 ◽  
Vol 339 ◽  
pp. 532-542 ◽  
Author(s):  
Jean Michel Grevy ◽  
Fabiola Tellez ◽  
Sylvain Bernés ◽  
Heinrich Nöth ◽  
Rosalinda Contreras ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Coordination Compounds ◽  
Transition Metal Ions ◽  
Main Group

scholarly journals Selective Chromogenic Recognition of Copper(II) Ion by Thiacalix[4]arene Tetrasulfonate and Mechanism

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 612 ◽  
Author(s):  
Shufang Zhu ◽  
Lilin Lu
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Density Functional ◽  
Color Change ◽  
Bathochromic Shift ◽  
Transition Metal Ions ◽  
Water Soluble ◽  
Ion Concentration ◽  
Absorption Bands ◽  
Simple Method

Detection of biologically important transition metal ions such as copper by using a simple method is desirable and of great importance. In this work, we firstly reported that water-soluble thiacalix[4]arene tetrasulfonate (TCAS) exhibited selective chromogenic recognition towards copper(II) ion over other transition metal ions. Color change from colorless to salmon pink was observed in TCAS solution, weak bathochromic shift was induced in UV absorption spectrum of TCAS upon addition of copper(II) ion, and the absorbance of characteristic absorption band at 312 nm increased linearly with copper(II) ion concentration. The recognition mechanism of TCAS to copper(II) ion was investigated by a comparative study with calix[4]arene tetrasulfonate (CAS) and time-dependent density functional theory(TD-DFT) study, and the absorption bands were assigned based on transition orbital analysis.

scholarly journals Activation and inhibition of rabbit muscle pyruvate kinase by transition-metal ions

1975 ◽  
Vol 145 (1) ◽  
pp. 63-71 ◽  
Author(s):  
S Ainsworth ◽  
N Macfarlane
Keyword(s):  
Transition Metal ◽  
Comparative Study ◽  
Metal Ions ◽  
Pyruvate Kinase ◽  
Transition Metal Ions ◽  
Kinetic Constants ◽  
Ion Concentration ◽  
Rabbit Muscle ◽  
Bivalent Cation ◽  
Muscle Pyruvate Kinase

The paper reports a comparative study of the effects of Mn2+, Ni2+ and Co2+ on the reaction of ADP with phosphoenolypyruvate when catalysed by K+-activated rabbit muscle pyruvate kinase. The activation and subsequent inhibition that occurs as the bivalent ion concentration is increased is taken as evidence that the substrates of the enzyme are phosphoenolypyruvate, uncomplexed ADP and free bivalent cation. Kinetic constants for the binding of the bivalent cation to the enzyme are reported.

HREM Study of electron-induced surface radiation damage in ReO3

1991 ◽  
Vol 49 ◽  
pp. 636-637
Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Oxides ◽  
Electron Irradiation ◽  
Transition Metal Oxides ◽  
Carbon Film ◽  
Transition Metal Ions ◽  
Surface Radiation ◽  
Valence Transition ◽  
Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

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