Chain conformation of polymers adsorbed to clay particles: effects of charge and concentration

Soft Matter ◽  
2021 ◽  
Author(s):  
Alan I. Nakatani ◽  
Carol E. Mohler ◽  
Stephanie Hughes
Keyword(s):  
Polymer Concentration ◽  
Chain Conformation ◽  
Clay Particle ◽  
Clay Particles

Schematic structure of PEO chains (red) adsorbed to a clay particle (blue) with increasing polymer concentration from (a) to (e).

scholarly journals Experimental Study of Profile Control with Foam Stabilized by Clay Particle and Surfactant

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 781 ◽  
Author(s):  
Songyan Li ◽  
Chenyu Qiao ◽  
Guowei Ji ◽  
Qun Wang ◽  
Lei Tao
Keyword(s):  
Anionic Surfactants ◽  
Resistance Factor ◽  
Clay Particle ◽  
Petroleum Engineering ◽  
Control Effect ◽  
Clay Particles ◽  
Profile Control ◽  
Water Cut ◽  
Deep Profile ◽  
Increasing Temperature

Foam is a kind of ideal fluid for profile control in petroleum engineering, which has attracted intense interests of scholars globally in recent years. In this study, a foam system stabilized with anionic surfactants and clay particles was proposed for profile control in reservoirs, and the formulation was optimized experimentally. Moreover, flooding experiments in visible porous media models and in sandpacks were conducted to test the plugging effect of the foam system on reservoirs, and the effects of different factors such as gas–liquid ratio, temperature and permeability on profile control were also evaluated. According to the experimental results, the clay-HY-2 system was elected for its satisfactory foamability, stability, and salinity resistance, and the optimum concentrations of HY-2 and clay particle are 0.6 wt% and 5.0 wt%, respectively. Compared with traditional foam fluids, the clay-HY-2 system can form denser and smaller bubbles in high- and middle-permeable layers, enhancing the plugging effect there, while there are less bubbles in low-permeable layers, i.e., the restriction on the flow in narrow structures is slight. The clay-HY-2 foam can perform the efficient and uniform profile control effect on sandpacks when the foam quality is around 50%. The resistance factor of the foam decrease gradually with the increasing temperature, however, the resistance factor remains higher than 350.0 when the temperature reaches 80.0 °C. When the permeability exceeds 1502.0 mD, the clay-HY-2 foam can perform deep profile control in reservoirs, and the resistance factor are not sensitive to the change of permeability when it exceeds 3038.0 mD. Besides, the site application case shows that the clay-HY-2 foam do have good profile control effect on reservoirs, i.e., improving oil production and declining water cut.

Influences of Change of Plasma on CBR of Eolian Sand

2011 ◽  
Vol 250-253 ◽  
pp. 3120-3127 ◽  
Author(s):  
Chang Ning Jin ◽  
Yu Hong Zhang
Keyword(s):  
Water Content ◽  
Clay Particle ◽  
Dry Density ◽  
Mechanism Analysis ◽  
Particle Content ◽  
Clay Particles ◽  
Eolian Sand ◽  
Cbr Test ◽  
Saturated Water Content ◽  
Test Result

The plasma in the eolian sand, included silt particle and clay particle, change easily and hugely. For studying their influences on the strength property of eolian sand, mixed silt particles and clay particles in different proportion into the eolian sand to carry out CBR test. The test result indicates that, along with the increase of silt particle and clay particle content the CBR value also increases within a certain range, which indicates the increase of silt particle and clay particle content can firstly improve the gradation of eolian sand; after the gradation is improved can obtain large compaction dry density, and at the same time also can enhance the earth strength, included the CBR value. The range of silt particle and clay particle content made the CBR value increase is also very large: ≤40% when formed under dry state, and ≤45% when formed under optimum or saturated water content; if the water content in forming could be retained at all times, the former could be ≤55% and the latter still ≤45%. The mechanism analysis further indicates that, when there were no excessive silt particles and clay particles, in the large range of silt particles and clay particles changing from small to large, the engineering nature of eolian sand will be improved due to the improvement of gradation, which is advantageous to the extensive application of dry compaction process; but the eolian sand formed by dry compaction is defective on microstructure, and so the requirements for silt particle and clay particle content should be more strict in practical works.

scholarly journals Experimental and Development of Polymer-Clay based Hybrid Nanocomposites

2019 ◽  
Vol 9 (2) ◽  
pp. 4200-4204
Keyword(s):  
Epoxy Resin ◽  
Wear Test ◽  
Clay Particle ◽  
Polymer Materials ◽  
Project Work ◽  
Peroxide Radical ◽  
X Ray Diffraction ◽  
Clay Particles ◽  
X Ray ◽  
Nano Clay

The hybrid polymer was arranged by using of halloysite nano tubular particles in hand lay-up method. Natural polymer materials have nano-clay particles; the epoxy resin was a chemical reaction of bonding two materials. The polymer material and nano clay particles are bonding with the epoxy resin. The amount of benzyl peroxide-radical initiator was analyzed by X-Ray diffraction method. The polymer nano clay particle and glass fiber are reinforced with epoxy-resin hybrid composites. The weight fractions of nano clay particle are 1.5, 2.5, and 3.5 % (by weight.) and Halloysite Nano tubular (HNT) clay joined together with polymer clay. In this project work was carried out wear test, tensile Strength X-ray Diffraction and SEM. In this project work conducted by wear test by Varying the loads and percentage of nano clay particles can be studied

Influence of changes in methanol concentration on clay particle interactions

1989 ◽  
Vol 26 (1) ◽  
pp. 57-63 ◽  
Author(s):  
John M. E. Storey ◽  
J. Jeffrey Peirce
Keyword(s):  
Hydraulic Conductivity ◽  
Clay Particle ◽  
Methanol Concentration ◽  
Atterberg Limits ◽  
Organic Liquids ◽  
Compacted Clay ◽  
Particle Settling ◽  
Liner Material ◽  
Clay Particles ◽  
Alcohol Water

The interactions of clay particles with alcohol–water mixtures are investigated with hydraulic conductivity measurements, the electrophoretic mobilities of the suspended particles are measured, particle settling tests are carried out, and Atterberg limits are determined. Organic liquids frequently interact with clay particles in the clay liners of surface impoundments. Such fluids can cause changes in hydraulic conductivity of the liner material. This study looks at the effects of dilution of a liquid hydrocarbon with water on the properties of a clay soil. Tests with 20, 40, 60, 80, and 100% (by volume) methanol concentrations are used to investigate the changes in hydraulic conductivity of water-compacted clay samples. Particle settling tests, Atterberg limits, and electrophoretic mobility studies are used with the same concentrations to determine the effects of changing methanol concentration on clay particle behavior. The results indicate that higher concentrations of methanol cause an increase in the attraction between the clay particles, and the same concentrations also cause an increase in hydraulic conductivity. Key words: Atterberg limits, clay, electrophoresis, hydraulic conductivity, methanol, settling tests, zeta potential.

Water Sensitivity of Sandstones

1983 ◽  
Vol 23 (01) ◽  
pp. 55-64 ◽  
Author(s):  
Kartic C. Khilar ◽  
H. Scott Fogler
Keyword(s):  
Mathematical Model ◽  
Fresh Water ◽  
Flow Rate ◽  
Salt Concentration ◽  
Particle Migration ◽  
Clay Particle ◽  
Permeability Reduction ◽  
Clay Particles ◽  
Water Sensitivity ◽  
Shock Experiment

Abstract Experimental and theoretical studies have been carried out to elucidate the mechanism of water sensitivity of Berea sandstone and to quantify a number of important parameters. Based on the results of a number of novel experiments, a physical model has been developed. In this model, clay particles are released only when the salt concentration falls below a critical salt concentration. These colloidal clay particles remain dispersed in fresh water and are carried with the flowing fluid until they are captured at a local pore constriction, thereby decreasing the permeability. A mathematical model based on this mechanism has been developed. This model contains two parameters stemming from the rate equations of the release and capture of clay particles. Correlations of these parameters with flow rate and temperature are presented. Introduction The water sensitivity of sandstone is a colloidal phenomenon whereby the permeability of the sandstone is decreased rapidly and significantly after the sandstone is contacted with fresh water. This phenomenon is demonstrated by a standard water shock experiment in which the flow through a sandstone core is changed abruptly from salt water to fresh water. The results of a standard water shock experiment are shown in Fig. 1. The normalized permeability (k/kl) drops from 1.0 to about 0.01 after only 2 or 3 PV of fresh water have been forced through the core. Permeability reduction resulting from water sensitivity is of serious concern to the oil- and gas-producing industries. Water sensitivity, first recognized during waterflooding of petroleum reservoirs, is now a concern in many other field operations that require aqueous solutions, such as drilling, solution mining, and stimulation. Even though water sensitivity in sandstone has been recognized for 35 years, the literature on this subject is limited. The works of Gray,1 Mungan,2,3 Jones,4 and Hewitt5 are among the most widely cited. These papers document the phenomenon and concur that the water sensitivity results from clay swelling, clay particle migration, or a combination of these effects, depending on the composition of the sandstone. Clay particle migration is the most important mechanism of permeability reduction since sandstones containing very little or no swelling clays and a considerable amount of migratory or dispersible clays such as kaolinite and illite are water-sensitive. Gray,1 Mungan,2,3 and Jones4 have reported results relating permeability reduction to clay particle migration. Previous studies investigated the effects of salt solutions, pH, and rate of decrease in salinity on the water sensitivity of sandstone. However, an in-depth analysis of the processes of dispersion and plugging of clay particles and how these processes are affected by flow rate, temperature, and salt concentration has not been reported in the literature. Some effects have been explained inadequately or incorrectly. These are discussed in detail elsewhere.6 In addition, a mathematical model describing quantitatively the permeability reduction with time and other parameters has not been developed. Such a model would aid in understanding the dynamics of this phenomenon as well as in designing preventive measures. The study of water sensitivity is also of general scientific interest since the phenomenon involves a number of colloidal and interfacial phenomena, such as flocculation, peptization, filtration, and adsorption. Practical considerations and scientific interests warrant a comprehensive study of this phenomenon. In this paper, a mathematical model is developed, and comparisons with experimental observations are made. These observations include permeability restoration with saltwater reversal, sequential permeability reduction, effect of flow rate, and core length.

scholarly journals Stochastic modeling of kaolinite transport through a sand filter

2019 ◽  
Vol 56 (11) ◽  
pp. 1573-1583 ◽  
Author(s):  
Jongmuk Won ◽  
Susan E. Burns
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Porous Media ◽  
Clay Particle ◽  
Coarse Grained ◽  
Sand Particle ◽  
Soil Matrix ◽  
Clay Particles ◽  
Grain Size Distributions ◽  
Coarse Grained Soil

Accurately modeling the transport of clay particles through coarse-grained porous media is essential to engineering applications ranging from filtration and drainage, groundwater flow modeling, to contaminant transport. However, predicting the retention and clogging behavior of clay particles within a coarse-grained soil matrix is extremely challenging because clay particles can aggregate and form clusters with a variety of fabrics depending on the prevailing geochemistry of the pore fluid (i.e., pH and ionic strength). The work performed in this study developed a stochastic model to investigate the uncertainty of clay particle transport in porous media using random sampling at a given grain-size distribution to account for inherent uncertainty of the size of clay clusters being transported. Results demonstrated that the model proposed in this work can evaluate upper and lower boundaries of retention profiles of clay particles in a sand medium at given mean and standard deviation of grain-size distributions. In addition, the deterministic approach (using median sizes of sand and clay particles in the simulation) underestimated the mass of retained particles at small size ratios of clay particle size/sand particle size when compared with the stochastic prediction, which would result in nonconservative design.

Structural component of the swelling pressure of calcium clays

Soil Research ◽  
1991 ◽  
Vol 29 (2) ◽  
pp. 209 ◽  
Author(s):  
JP Quirk ◽  
RM Pashley
Keyword(s):  
Structural Component ◽  
Swelling Pressure ◽  
Normal Structure ◽  
Disjoining Pressure ◽  
Clay Particle ◽  
Clay Particles ◽  
Structural Force

The presence of a major repulsive ion-induced structural force or disjoining pressure between Ca-clay particles is demonstrated. This arises from the perturbation of the normal structure for water to distances of about 50 A. This force operates in slit-shaped pores between clay particles and is opposed principally by attractive ion-ion correlation forces in regions of clay particle overlap.

Qualitative Analysis of the Effect of Polymer Solution and Suspension Properties on the Electrospinning of Nanocomposite Fibers

2013 ◽  
Vol 686 ◽  
pp. 65-70 ◽  
Author(s):  
Khryslyn Araño ◽  
Michael Leo Dela Cruz ◽  
Eden May Dela Pena ◽  
Leslie Joy L. Diaz
Keyword(s):  
Polymer Solution ◽  
Polymer Concentration ◽  
Electrospinning Process ◽  
Sem Images ◽  
Xrd Pattern ◽  
Clay Particles ◽  
Polymer Molecules ◽  
Modified Montmorillonite ◽  
Nanocomposite Fibers ◽  
Common Defect

Nanocomposite fibers produced via electrospinning have very large surface area by virtue of their nanometer diameter sizes thereby making them very attractive for various applications such as for adsorption of contaminants from wastewater. In this study, a highly adsorbing nanoparticle, iron-modified montmorillonite was used as filler in the nanocomposite. The effects of polymer solution and suspension properties such as polymer concentration, clay loading, and filler type on the electrospinning of the nanocomposite were investigated using a 2k factorial design of experiment. The types of montmorillonite used were zero valent iron-MMT (ZVIMMT) and iron (III)-MMT (FeMMT). It was found from the SEM images that finer fibers were generated from suspensions with lower polymer concentration in the solution specifically at 5 wt% and from suspensions with ZVIMMT particles as filler. However, a common defect in nanofibers called beads was also observed in the fibers produced from 5 wt% polymer concentration. TEM micrographs confirmed that the ZVIMMT fibers have smaller diameter than the FeMMT fibers. In addition, it was recognized that the layered structure of the clay is still intact after the electrospinning process. The XRD pattern of the fibers revealed that the clay particles were intercalated with the polymer molecules based on the calculated d-spacing. Furthermore, elemental analysis on the bead and string regions of the electrospun fibers confirmed the presence of polymer and montmorillonite particles in both regions.

Deciphering the science behind electrocoagulation remove suspended clay particles from water

2004 ◽  
Vol 50 (12) ◽  
pp. 177-184 ◽  
Author(s):  
P.K. Holt ◽  
G.W. Barton ◽  
C.A. Mitchell
Keyword(s):  
Batch Reactor ◽  
Clay Particle ◽  
Removal Mechanism ◽  
Dissolved Air Flotation ◽  
Clay Particles ◽  
Hydrogen Bubbles ◽  
Air Flotation ◽  
Aluminium Anode ◽  
Dissolved Air

Electrocoagulation removes pollutant material from water by a combination of coagulant delivered from a sacrificial aluminium anode and hydrogen bubbles evolved at an inert cathode. Rates of clay particle flotation and settling were experimentally determined in a 7 L batch reactor over a range of currents (0.25-2.0 A) and pollutant loadings (0.1-1.7 g/L). Sedimentation and flotation are the dominant removal mechanism at low and high currents, respectively. This shift in separation mode can be explained by analysing the reactor in terms of a published dissolved air flotation model.

Application of a Simple Cold Stub to the Direct Observation of Frozen Hydrated Sand

1973 ◽  
Vol 31 ◽  
pp. 212-213
Author(s):  
John M. Wehrung ◽  
Richard J. Harniman
Keyword(s):  
United States ◽  
Surface Water ◽  
Direct Observation ◽  
Controlled Study ◽  
Clay Particles ◽  
Organic Debris ◽  
Rock Formations ◽  
Water Tables ◽  
Permeable Rock ◽  
Natural Means

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.

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