Investigation on thermodynamic parameters and stability of some polyelectrolyte complexes with respect to ionic strength of the medium

2008 ◽  
Vol 61 (2) ◽  
pp. 247-255 ◽  
Author(s):  
B. Vasheghani F. ◽  
F. H. Rajabi ◽  
M. H. Ahmadi ◽  
F. Mashhadi
Keyword(s):  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Polyelectrolyte Complexes

Polymerization of acrylonitrile initiated by peroxomonosulphate-thiols redox systems

1990 ◽  
Vol 55 (8) ◽  
pp. 2001-2007
Author(s):  
Gurusamy Manivannan ◽  
Pichai Maruthamuthu
Keyword(s):  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Thermal Polymerization ◽  
Reaction Scheme ◽  
Degree Of Polymerization ◽  
Reducing Agent ◽  
Redox Systems ◽  
Temperature Range ◽  
Rate Of Polymerization

Aqueous thermal polymerization of acrylonitrile (AN) initiated by peroxomonosulphate (HSO5-, PMS)-thiolactic acid (TLA) and PMS-thiomalic acid (TMA) redox systems has been carried out in the temperature range 30-50 °C. The effect of concentration of monomer, initiator, reducing agent, H+, and ionic strength on rate of polymerization, Rp, has been investigated under deaerated conditions. The Rp has been found to depend on, Rp ~ [AN]01.5 [PMS]0.5 [TLA]0.5 in PMS-TLA system and, Rp ~ [AN]02.0 [PMS]1.0 [TMA]0 in PMS-TMA system. The degree of polymerization (Xn) values and thermodynamic parameters have been evaluated. Suitable reaction scheme has been proposed and expressions for Rp and Xn have been obtained.

scholarly journals Potentiometric and spectrophotometric studies of the complexation of Schiff-base hydrazones containing the pyrimidine moiety

2003 ◽  
Vol 68 (10) ◽  
pp. 729-749 ◽  
Author(s):  
H.S. Seleem ◽  
B.A. El-Shetary ◽  
S.M.E. Khalil ◽  
M. Shebl
Keyword(s):  
Schiff Base ◽  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Stability Constants ◽  
Elemental Analysis ◽  
Mass Spectra ◽  
Dissociation Constants ◽  
The Stability ◽  
Pyrimidine Moiety ◽  
Metal Ligand

Three Schiff-base hydrazones (ONN ? donors) were prepared by condensation of 2-amino-4-hydrazino-6-methylpyrimidine with 2-hydroxyacetophenone 2-methoxybenzaldehyde and diacetyl to yield 2-OHAHP, 2-OMeBHPand DHP respectively. The structures of these ligands were elucidated by elemental analysis, UV, IR, 1H-NMR and mass spectra. The metal?ligand stability constants of Mn2+, Fe3+,Co2+,Ni2+,Cu2+, Zn2+,Cd2+,UO22+ and Th4+ chelates were determined potentiometrically in two different media (75%(v/v) dioxane?water and ethanol?water) at 283, 293, 303 and 313 K at an ionic strength of 0.05 M (KNO3). The thermodynamic parameters of the 1:1 and 1:2 complexes were evaluated and are discussed. The dissociation constants of 2-OHAHP, 2-OMeBHP and DHPligands and the stability constants of Co2+, Ni2 and Cu2+ with 2-OHAHP were determined spectrophotometrically in 75 % (v/v) dioxane?water.

Insights into cationic methyl violet 6B dye–kaolinite interactions: kinetic, equilibrium and thermodynamic studies

Clay Minerals ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 85-95 ◽  
Author(s):  
İ. Sargin ◽  
N. Ünlü
Keyword(s):  
Experimental Data ◽  
Ionic Strength ◽  
Adsorption Capacity ◽  
Thermodynamic Parameters ◽  
Adsorption Kinetics ◽  
Adsorption Process ◽  
Methyl Violet ◽  
Order Type ◽  
Kinetic And Thermodynamic Parameters ◽  
Initial Ph

AbstractIn this study, adsorption and adsorption kinetics of methyl violet dye from aqueous solutions onto kaolinite were investigated. The effects of adsorbent dosage, pH, ionic strength, contact time, temperature and initial dye concentration were studied. Kinetic and thermodynamic parameters were determined using experimental data. Adsorption capacity decreased with increasing ionic strength. Changes in the initial pH of the dye solution in a range close to the dye's natural pH (i.e. ∼ pH 5.0) values affected adsorption capacity slightly, indicating that adsorption studies could be carried out at the dye's natural pH. The adsorption process followed the Freundlich-type adsorption isotherms and pseudo-second order type adsorption kinetics. However, an intraparticle diffusion process was found to have effects in adsorption processes. Thermodynamic parameters were calculated from the experimental data and enthalpy of the adsorption, ΔH0, was found to be –6.82 kJ mol–1, indicating physisorption nature of the adsorption. Other thermodynamic parameters, ΔS0 and DG0, were also calculated. Negative values of ΔG0 indicated that the adsorption process for methyl violet on kaolinite is spontaneous.

scholarly journals The influence of ionic strength and mixing ratio on the colloidal stability of PDAC/PSS polyelectrolyte complexes

Soft Matter ◽  
2015 ◽  
Vol 11 (37) ◽  
pp. 7392-7401 ◽  
Author(s):  
Yanpu Zhang ◽  
Erol Yildirim ◽  
Hanne S. Antila ◽  
Luis D. Valenzuela ◽  
Maria Sammalkorpi ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Colloidal Stability ◽  
Mixing Ratio ◽  
Polyelectrolyte Complexes ◽  
Over Time

Over time, polyelectrolyte complexes aggregate, dissolve, or remain colloidally stable.

Calcium—malonate complexes in aqueous solution. Thermodynamic parameters and their ionic strength dependence

1984 ◽  
Vol 72 (3) ◽  
pp. 305-322 ◽  
Author(s):  
Pier G. Daniele ◽  
Alessandro de Robertis ◽  
Silvio Sammartano ◽  
Carmelo Rigano
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Ionic Strength Dependence ◽  
Strength Dependence

Joint interaction of ethidium bromide and methylene blue with DNA. The effect of ionic strength on binding thermodynamic parameters

2016 ◽  
Vol 34 (7) ◽  
pp. 1377-1382 ◽  
Author(s):  
Poghos O. Vardevanyan ◽  
Ara P. Antonyan ◽  
Marine A. Parsadanyan ◽  
Margarita A. Torosyan ◽  
Armen T. Karapetian
Keyword(s):  
Methylene Blue ◽  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Ethidium Bromide

Alginate Polyelectrolyte Ionotropic Gels-XVI. Kinetics and Chemical Equilibria Studies for Heterogeneous Ion Exchange of Polyvalent Metal Ions in Alginate Gel Complexes

1992 ◽  
Vol 4 (3) ◽  
pp. 173-179 ◽  
Author(s):  
S. A. El-Shatoury ◽  
R. M. Hassan ◽  
A. A. Said
Keyword(s):  
Ionic Strength ◽  
Ion Exchange ◽  
Metal Ions ◽  
Thermodynamic Parameters ◽  
Coordination Geometry ◽  
Ionic Radii ◽  
Chemical Equilibria ◽  
Polyvalent Metal ◽  
Alginate Gel ◽  
Counter Ions

The kinetics or chemical equilibria of exchange of Ca(II), Sr(II), Ba(I), Zn(II), Cd(II), Al(III), Fe(III), Se(IV), Ce(IV) and Th(IV) counter ions in alginate gel complexes by H+ ions have been investigated titrimetrically and conductimetrically at a constant ionic strength of 0.1 mol/dm3. The thermodynamic parameters have been evaluated and are discussed in terms of ionic radii and polarizability of the metal ions, coordination geometry, and stability of the gel complexes.

Emerging trends in the dynamics of polyelectrolyte complexes

2020 ◽  
Vol 22 (42) ◽  
pp. 24157-24177
Author(s):  
Suvesh Manoj Lalwani ◽  
Chikaodinaka I. Eneh ◽  
Jodie L. Lutkenhaus
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Water Content ◽  
Dynamic Responses ◽  
Polyelectrolyte Complexes ◽  
Emerging Trends

Polyelectrolyte complexes (PECs) exhibit varying dynamic responses depending upon the ionic strength, water content, temperature, pH, and molecular weight.

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