scholarly journals Adsorption of Polyelectrolytes at the Manganese Oxide(IV)–Polymer Solution Interface: Structure of Adsorbed Layers

2002 ◽  
Vol 20 (5) ◽  
pp. 511-522 ◽  
Author(s):  
S. Chibowski ◽  
M. Wiśniewska ◽  
M. Paszkiewicz

The influence of the molecular weight of polyelectrolytes on their adsorption and on the structure of the adsorbed layers at the manganese oxide(IV)–polymer solution interface was determined. Polyacrylic acid (PAA) and polyacrylamide (PAM) were applied as ionic polymers. An explanation was proposed for the observed changes in surface charge and zeta potential of the solid in the presence of these polymers. The thickness of the adsorption layer of PAA and PAM was determined and the free energies of adsorption of these polymers on the MnO2 surface were calculated from the zeta potential measurements.

2001 ◽  
Vol 19 (5) ◽  
pp. 397-407 ◽  
Author(s):  
S. Chibowski ◽  
M. Paszkiewicz

In the studies presented, the influence of the molecular weight of polyethylene glycol (PEG) on the adsorption and electrical properties at the metal oxide/polymer solution interface has been determined. The main factors responsible for the observed changes in the zeta potential and surface charge of titania were determined on the basis of the data obtained. It was demonstrated that changes in the ionic structure of the Stern layer depend on the molecular weight of PEG and its conformation. A possible mechanism for the changes in zeta potential both with pH and molecular weight was proposed on the basis of values of the surface charge difference (Δσ0) and the diffuse layer charge difference (Δσd) as determined in the presence and absence of the polymer. The thickness of the adsorption layer (δ) on the surface of titania was calculated from the zeta potential changes, both in the presence and absence of the polymer. A distinct influence of the PEG molecular weight was noted on the values of the adsorption layer thickness (δ) determined. The structures of the macromolecules in solution and at the solid/solution interface were compared and from the dependencies obtained some changes in the shape and dimensions of the polymer coils on passing from the bulk solution to the interface were proposed.


2001 ◽  
Vol 19 (5) ◽  
pp. 409-421 ◽  
Author(s):  
S. Chibowski ◽  
M. Wiśniewska

The influence of the molecular weight of polyacrylic acid (PAA) and polyacrylamide (PAM) as well as of inorganic contaminants on the ZrO2 surface on the adsorption and electrokinetic properties of the metal oxide/polyelectrolyte solution interface were studied for ZrO2 and Fe2O3 solid particles. The calculated concentrations of the various surface groups on ZrO2 and Fe2O3 enabled an investigation of the possible mechanism for the bonding of the studied polyelectrolytes with the surfaces of both oxides. PAA and PAM macromolecules bond with the solid surface mainly via the –OH groups of the oxides, which may interact with the carboxy groups of polyelectrolytes through hydrogen bridging. A comparison of the change in values of the diffuse layer charge with the surface charge enabled the principal factors responsible for the changes in the zeta potential of the oxides, e.g. pH, polymer molecular weight and concentration of the polymer solutions, to be evaluated. From such zeta potential values, it was possible to determine the free energies of adsorption of PAA and PAM on the surfaces of both oxides. The thicknesses of adsorbed polymer layers on Fe2O3 and ZrO2 were calculated on the basis of measurements of their suspension viscosities in the absence and presence of adsorbed polymer. It was shown that the thickness of the adsorption layer increased with increasing polymer molecular weight, pH and concentration of the polymer solution. Because the experimental determination of the number and the length of trains, loops and tails in such polyelectrolytes was not possible, the participation of such segments of polymer structure at the interface was computed using the Scheutjens–Fleer model of polymer adsorption. The polymer adsorption expressed as the number of equivalent monolayers was calculated and compared with the experimental data.


Author(s):  
Ghazaleh Allaedini ◽  
Patrick Zhang

A total of nine polymers were first tested. Correlations between molecular weight and sludge settling rate were identified for three types of polymers with a general trend of higher molecular weight giving a faster settling rate. Among the non-ionic polymers, the medium molecular weight polymer produced the best results (1831.88 ppm). Among the cationic flocculants, the lowest molecular weight polymer resulted in more REEs distribution (2478.81 ppm). It was concluded that the super high molecular weight of anionic flocculants works best for treating phosphoric acid sludge which resulted in REE concentration of 2568.69 ppm. Five co-polymers with different anionic ratio were tested as well. A higher anionic ratio resulted in faster settlement. It was found that the higher was the anionic ratio of the flocculant, the higher was REE concentration in the final solids and the highest anionic ratio polymer resulted in 2999.64 ppm of REE. This trend was attributed to zeta potential change due to addition of the polymer.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 319 ◽  
Author(s):  
Bin Huang ◽  
Xiaohui Li ◽  
Cheng Fu ◽  
Ying Wang ◽  
Haoran Cheng

Previous studies showed the difficulty during polymer flooding and the low producing degree for the low permeability layer. To solve the problem, Daqing, the first oil company, puts forward the polymer-separate-layer-injection-technology which separates mass and pressure in a single pipe. This technology mainly increases the control range of injection pressure of fluid by using the annular de-pressure tool, and reasonably distributes the molecular weight of the polymer injected into the thin and poor layers through the shearing of the different-medium-injection-tools. This occurs, in order to take advantage of the shearing thinning property of polymer solution and avoid the energy loss caused by the turbulent flow of polymer solution due to excessive injection rate in different injection tools. Combining rheological property of polymer and local perturbation theory, a rheological model of polymer solution in different-medium-injection-tools is derived and the maximum injection velocity is determined. The ranges of polymer viscosity in different injection tools are mainly determined by the structures of the different injection tools. However, the value of polymer viscosity is mainly determined by the concentration of polymer solution. So, the relation between the molecular weight of polymer and the permeability of layers should be firstly determined, and then the structural parameter combination of the different-medium-injection-tool should be optimized. The results of the study are important for regulating polymer injection parameters in the oilfield which enhances the oil recovery with reduced the cost.


Langmuir ◽  
1995 ◽  
Vol 11 (7) ◽  
pp. 2621-2625 ◽  
Author(s):  
Lars Oedberg ◽  
Sussan Sandberg ◽  
Stefan Welin-Klintstroem ◽  
Hans Arwin

Langmuir ◽  
2007 ◽  
Vol 23 (4) ◽  
pp. 2083-2090 ◽  
Author(s):  
Jérôme Labille ◽  
Nicolas Fatin-Rouge ◽  
Jacques Buffle

Author(s):  
Władysław Janusz ◽  
Ewa Skwarek

AbstractThe aim of the study was the basic incidence on the phenomenon of adsorption that occurs at the hydroxyapatite/malic acid interface, leading to a change in the surface properties of hydroxyapatite, Analytical methods used in the research: X-ray diffraction (XRD) as well as by the, adsorption–desorption of nitrogen (ASAP), potentiometric titration. The specific adsorption of malic acid ions at the hydroxyapatite interface was investigated by means of the radioisotope method. The zeta potential of hydroxyapatite dispersions was determined by electrophoresis with Zetasizer Nano ZS90 by Malvern. The particle sizes of hydroxyapatite samples were analyzed using Masteriszer 2000 Malvern. Studies on the kinetics of malic acid on hydroxyapatite from a solution with an initial concentration of 1 mmol/dm3 have shown that the adsorption process is initially fast, followed by a slow adsorption step. An increase in the pH of the solution causes a decrease in the malic acid adsorption as a result of competition with hydroxyl ions. The presence of adsorbed malic acid was confirmed by the FTIR measurements. The effect of malic acid adsorption on the zeta potential and particle size distribution of hydroxyapatite in the NaCl solution was investigated.


2002 ◽  
Vol 20 (6) ◽  
pp. 573-582 ◽  
Author(s):  
S. Chibowski ◽  
M. Paszkiewicz ◽  
M. Wiśniewska

The influence of sodium dodecyl sulphate (SDS) on the adsorption properties of non-ionic polymers, i.e. polyethylene glycol (PEG) and polyvinyl alcohol (PVA), at the Al2O3/solution interface was studied. Measurements for various molecular weights and for various amounts of functional groups on the polymer macromolecules were undertaken and the results obtained discussed in the light of these variations. Studies of the mutual interactions of the polymer–surfactant system in aqueous solution were helpful in explaining the equilibria involved in the Al2O3/polymer solution system in the presence of SDS. The thickness of the adsorption layer was determined by viscometric methods and the influence of the degree of hydrolysis of PVA on the structure of the adsorption layer demonstrated.


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