Adsorption scaling theory for investigation of distance between clay-layers with adsorbed polymer and adsorption-isotherm versus polymer-concentration: Comparison to experiment

2021 ◽  
Vol 200 ◽  
pp. 110769
Author(s):  
Souad Ghyati ◽  
Said Kassou ◽  
El Hassan El Kinani ◽  
Mabrouk Benhamou
Keyword(s):  
Adsorption Isotherm ◽  
Polymer Concentration ◽  
Scaling Theory ◽  
Adsorbed Polymer ◽  
Clay Layers

Adsorption of monodisperse polybutadienes on carbon black, 1 Adsorption from dilute and semi-dilute solutions

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Kathy Vuillaume ◽  
Bassel Haidar ◽  
Alain Vidal
Keyword(s):  
Carbon Black ◽  
Polymer Chain ◽  
Anionic Polymerization ◽  
Polymer Concentration ◽  
Three Dimensional ◽  
Percolation Process ◽  
Molecular Weights ◽  
Polymer Filler ◽  
Adsorbed Polymer ◽  
Filler Network

Abstract A series of polybutadienes (PBs) of different molecular weights (in the range of 3000 to 120 000) but of identical microstructure (1,2-PB content ≈ 80%) was synthesized via anionic polymerization. The adsorption in solution of the various monodisperse PBs on carbon black (CB) was studied for different polymer/ CB ratios as well as for polymer and CB concentrations in the range of 0.1 to 100 g/l. The amount of adsorbed polymer was followed and was found to be essentially governed by the polymer concentration, which determines also the conformation of the polymer chain on the filler surface. CB concentration didn’t prove to be a pertinent parameter, whereas the polymer/filler ratio was found to control the formation of the three-dimensional polymer-filler network on the basis of a percolation process. Results are discussed with respect to the available theories.

Effect of Concentration on HPAM Retention in Porous Media

SPE Journal ◽  
2014 ◽  
Vol 19 (03) ◽  
pp. 373-380 ◽  
Author(s):  
Guoyin Zhang ◽  
R.S.. S. Seright
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Polymer Solution ◽  
Polymer Concentration ◽  
Retention Mechanism ◽  
Dynamic Measurements ◽  
Polymer Molecules ◽  
Adsorbed Polymer ◽  
Hydrolyzed Polyacrylamide ◽  
Polymer Retention

Summary This paper investigates the effect of hydrolyzed polyacrylamide (HPAM) polymer concentration on retention in porous media by use of both static and dynamic measurements. Consistent results by use of these two methods show that different polymer-retention behaviors exist in dilute, semidilute, and concentrated regions. In both the dilute and concentrated regions, polymer retention has little dependence on concentration. In contrast, in the semidilute region, polymer retention is concentration dependent. If a porous medium is first contacted sufficiently with dilute polymer solution to satisfy the retention, no significant additional retention occurs during exposure to higher HPAM concentrations. On the basis of the experimental results, a concentration-related retention mechanism is proposed that considers the orientation of the adsorbed polymer molecules and the interaction between molecular coils in solution. By use of this model, we explain why polymer retention does not show much dependence on concentration in the dilute and concentrated regimes. Further, in the semidilute region, we explain how moderate coil interactions lead to mixed adsorbed-polymer orientation and magnitude on rock surfaces, and retention becomes concentration dependent. In field applications of polymer and chemical floods, reduced polymer retention may be achieved by first injecting a low-concentration polymer bank.

scholarly journals Stabilizing Na-bentonite by Poly(Diallyl Dimethyl Ammonium Chloride) Adsorption

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Mohamed ABDEL-KHALEK ◽  
Ayman EL-MIDANY
Keyword(s):  
Adsorption Isotherm ◽  
Ammonium Chloride ◽  
Polymer Concentration ◽  
Chemical Properties ◽  
Freundlich Isotherm ◽  
Head Group ◽  
Polymer Addition ◽  
Dimethyl Ammonium Chloride ◽  
Dimethyl Ammonium ◽  
Diallyl Dimethyl Ammonium Chloride

Clay minerals have been modified by polymers for different applications. The polymer addition affects not only the surface propertiesbut also the rheological properties and the stability of the clay-polymer suspension as a whole. In the current study, the electro-chemical properties of bentonite particles in presence of poly diallyl dimethyl ammonium chloride (PDDACl) were investigated. Theseproperties were characterized by as zeta potential, adsorption isotherm, Fourier transform infrared (FTIR) and the apparent viscosityat different solid percent. The results indicated that the viscosity of the bentonite-PDDACl suspension not only increases by raising thepolymer concentration but also by increasing solids %. Adsorption of PDDACl polymer increases the positivity of bentonite surfaceas a function of polymer concentration, which could be explained mainly by electrostatic interaction of deficient metal ions at theoctahedral sheets of bentonite with the cationic head group of the polymer. The PDDACl adsorption isotherm on bentonite fits moreprobably Langmuir than Freundlich isotherm

Density Profiles of Semi-Dilute Polymer Solutions Near a Hard Wall: Monte Carlo Simulation

1989 ◽  
Vol 153 ◽  
Author(s):  
Wan Y. Shih ◽  
Wei-Heng Shih ◽  
Ilhan A. Aksay
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Polymer Solutions ◽  
Polymer Concentration ◽  
Scaling Theory ◽  
Hard Wall ◽  
Density Profiles ◽  
Bulk Properties ◽  
Dilute Polymer Solutions ◽  
Physical Quantities

A semi-dilute polymer solution is one in which polymers overla1p. The bulk properties of semi-dilute polymer solutions have been studied extensively and much has been known. The scaling theory has been very successful. 1,2 The predictions of the scaling theory about various physical quantities as a function of polymer concentration, c, have been confirmed experimentally. 1,3

scholarly journals Deposition of Synthetic and Bio-Based Polycations onto Negatively Charged Solid Surfaces: Effect of the Polymer Cationicity, Ionic Strength, and the Addition of an Anionic Surfactant

2020 ◽  
Vol 4 (3) ◽  
pp. 33 ◽  
Author(s):  
María Hernández-Rivas ◽  
Eduardo Guzmán ◽  
Laura Fernández-Peña ◽  
Andrew Akanno ◽  
Andrew Greaves ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Chemical Nature ◽  
Theoretical Calculations ◽  
Polymer Concentration ◽  
Mean Field ◽  
Chemical Properties ◽  
Industrial Applications ◽  
Polymer Chains ◽  
Charged Surfaces ◽  
Adsorbed Polymer

The deposition of layers of different polycations (synthetic or derived from natural, renewable resources) onto oppositely charged surfaces has been studied using ellipsometry and quartz crystal microbalance with dissipation monitoring (QCM-D). Information about the thickness of the deposited layers and their water content was ascertained. The adsorption of the different polycations onto negatively charged surfaces was found to be a complex process, which is influenced by the chemical nature of the polymer chains, ionic strength, polymer concentration and the addition of additives such as surfactants. The experimental picture shows a good agreement with theoretical calculations performed using the Self-Consistent Mean Field (SCF) approach. The results show that the electrostatically-driven deposition can be tuned by modifying the physico-chemical properties of the solutions and the chemical nature of the adsorbed polymer. This versatile approach is a big step forward in aiding the design of new polymers for many industrial applications and, in particular, the design of sustainable washing formulations for cosmetic applications.

Computer averaging of lattice images of poly-4-methyl-pentene-1 (P4mp1): Noise created artifacts

1987 ◽  
Vol 45 ◽  
pp. 388-389
Author(s):  
P. Pradère ◽  
J.F. Revol ◽  
R. St. John Manley
Keyword(s):  
Low Dose ◽  
Polymer Concentration ◽  
Processing System ◽  
Limiting Factor ◽  
Dilute Solution ◽  
New Techniques ◽  
Dose Unit ◽  
Lattice Images ◽  
Dose Imaging ◽  
Imaging Conditions

Although radiation damage is the limiting factor in HREM of polymers, new techniques based on low dose imaging at low magnification have permitted lattice images to be obtained from very radiation sensitive polymers such as polyethylene (PE). This paper describes the computer averaging of P4MP1 lattice images. P4MP1 is even more sensitive than PE (total end point dose of 27 C m-2 as compared to 100 C m-2 for PE at 120 kV). It does, however, have the advantage of forming flat crystals from dilute solution and no change in d-spacings is observed during irradiation.Crystals of P4MP1 were grown at 60°C in xylene (polymer concentration 0.05%). Electron microscopy was performed with a Philips EM 400 T microscope equipped with a Low Dose Unit and operated at 120 kV. Imaging conditions were the same as already described elsewhere. Enlarged micrographs were digitized and processed with the Spider image processing system.

Preparation and In-vitro Evaluation of Fe3O4 Encapsulated by Chitosan Loaded Capecitabine Nanoparticles for the Treatment of Breast Cancer

2016 ◽  
Vol 6 (3) ◽  
Author(s):  
Shanmuganathan S. ◽  
Nigma S. ◽  
Anbarasan B. ◽  
Harika B.
Keyword(s):  
Fe3o4 Nanoparticles ◽  
Polymer Concentration ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
In Vitro Evaluation ◽  
Sem Image ◽  
Therapeutic Molecules ◽  
Dialysis Method ◽  
Vitro Release

Nanoparticulate Carriers which is biodegradable, biocompatible and bio adhesive have significant feasible applications for administration of therapeutic molecules. The present study was aimed to formulate and optimise Capecitabine loaded Chitosan-Fe3O4 Nanoparticles and to study the in-vitro evaluation by sigma dialysis method. Capecitabine loaded chitosan – Fe3O4 nanoparticles batches with different ratios of drug: polymer (1:1, 1:2, 1:3, 1:4, 1:5, 1:6) were prepared by ionic gelation method. Increase in polymer concentration increases the nanoparticle drug content. Entrapment efficiency was 60.12% with drug to polymer ratio F3 (1:3). In-vitro release was found to be 65.20% for 12 hrs. Capecitabine from chitosanFe3O4 nanoparticles SEM image reveals discrete spherical structure and particles with size range of 100-500nm. FTIR studies represent the functional groups present with no characteristics change in formulations. Samples stored at refrigerator conditions showed better stability compared with samples kept at other conditions during 8 weeks of storage.

Influence of Formulation Variables and Processing Techniques on Drug Release from Carbopol-971 based Matrix Tablets of Cinnarizine and Nimodipine.

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Singh K. ◽  
Pandit K. ◽  
Mishra N.
Keyword(s):  
Drug Release ◽  
Release Rate ◽  
Polymer Concentration ◽  
Matrix Tablets ◽  
Wet Granulation ◽  
Weight Variation ◽  
Diffusion Controlled ◽  
The Matrix ◽  
Processing Techniques ◽  
Formulation Variables

The matrix tablets of cinnarizine and nimodipine were prepared with varying ratio of Carbopol- 971P and co-excipients of varying hydrophilicity (i.e. dicalcium phosphate and spray dried lactose) by direct compression and wet granulation using alcoholic mucilage. The prepared tablets were evaluated for weight variation, hardness and friability. The influence of concentration of the matrix forming material and co-excipients on the release rate of the drug was studied. The release rate of Cinnarizine (more soluble drug) from tablets followed diffusion controlled mechanism whereas for nimodipine (less soluble drug), the drug release followed case-II or super case- II transport mechanism based on Korsmeyer- Peppas equation. The results indicated that the drug release from matrix tablets was increases with increase in hydrophilicity of drug and co-excipients. The release of drug also increased with thermal treatment and decreasing polymer concentration.

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