Enhanced dewatering of oil sands tailings by a novel water-soluble cationic polymer

Vajihinejad, Vahid; Gumfekar, Sarang P.; Dixon, Daniel V.; Silva, Marco Antônio; Soares, João B. P.

doi:10.1016/j.seppur.2020.118183

Cited by 16 publications

(13 citation statements)

References 23 publications

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“…Attempts to resolve the issue by varying the composition of the mobile phase and column priming were unsuccessful. This is consistent with prior reports that GPC analysis of hydrophobically modified cationic polymers, which have a tendency for aggregation and flocculation, has been notoriously difficult. , Therefore, the molecular weights were assessed by alternative methodsDLS and AF4 measurements using water-soluble polyphosphazene standards, which were characterized as described previously . Note that the hydrodynamic dimensions of polymers determined by DLS were earlier successfully correlated with their molecular masses determined using GPC with static light scattering detection or analytical ultracentrifugation. , Here, the DLS molecular masses were evaluated from the diameter–molecular mass calibration curves using z-average hydrodynamic diameters (Figure S5) and are shown in Table .…”

Section: Resultssupporting

confidence: 80%

“…However, compared to GPC, interactions with the stationary phase are further minimized as separation is achieved by applying a cross-flow of a mobile phase against the surface of a semipermeable membrane . The applicability of this method to the molecular mass analysis of polymers has been also successfully demonstrated previously. , Figure S6 shows AF4 fractograms of both fluorinated polymers along with representative profiles of the molecular standards and the calibration curve. AF4 results were in agreement with DLS measurements indicating that the molecular masses of both polymers were in excess of 100 kDa, and the molecular mass of PFAP-O was somewhat higher than that of PFAP-A (Table ).…”

Section: Resultsmentioning

confidence: 78%

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Cationic Fluoropolyphosphazenes: Synthesis and Assembly with Heparin as a Pathway to Hemocompatible Nanocoatings

Marin

Brito

Sukhishvili

et al. 2021

ACS Appl. Bio Mater.

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The development of state-of-the-art blood-contacting devices can be advanced through integrating hemocompatibility, durability, and anticoagulant functionalities within engineered nanoscale coatings. To enable all-aqueous assembly of nanocoatings combining omniphobic fluorinated features with the potent anticoagulant activity of hydrophilic heparin, two fluoropolymers containing cationic functionalities were synthesizedpoly[(trifluoroethoxy)(dimethylaminopropyloxy)phosphazene], PFAP-O, and poly[(trifluoroethoxy)(dimethylaminopropylamino)phosphazene], PFAP-A. Despite a relatively high content of fluorinated pendant groupsapproximately 50% (mol) in eachboth polymers displayed solubility in aqueous solutions and were able to spontaneously form stable supramolecular complexes with heparin, as determined by dynamic light scattering and asymmetric flow field-flow fractionation methods. Heparin-containing coatings were then assembled by layer-by-layer deposition in aqueous solutions. Nanoassembled coatings were evaluated for potential thrombogenicity in three important categories of in vitro testscoagulation by thrombin generation, platelet retention, and hemolysis. In all assays, heparin-containing fluoro-coatings consistently displayed superior performance compared to untreated titanium surfaces or fluoro-coatings assembled using poly(acrylic acid) in the absence of heparin. Short-term stability studies revealed the noneluting nature of these noncovalently assembled coatings.

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Section: Resultssupporting

confidence: 80%

Section: Resultsmentioning

confidence: 78%

Cationic Fluoropolyphosphazenes: Synthesis and Assembly with Heparin as a Pathway to Hemocompatible Nanocoatings

Marin

Brito

Sukhishvili

et al. 2021

ACS Appl. Bio Mater.

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“…The MFT was diluted to 5 wt % to achieve uniform mixing, attain rapid settling, and identify the difference in performance upon flocculant addition. ,, The dilution was performed using deionized water, and the slurry was homogenized by mixing it at 300 rpm for 1 min prior to the addition of a flocculant. The flocculation tests used a mixture of the diluted MFT, 2000 ppm of EPDM- g -HPMAs, and 1000 ppm of Ca 2+ (1 M CalCl 2 ), totaling 1000 mL.…”

Section: Materials and Methodsmentioning

confidence: 99%

Flocculation Efficiency and Spatial Distribution of Water in Oil Sands Tailings Flocculated with a Partially Hydrophobic Graft Copolymer

Kalyanaraman

Najafabadi

Soares

et al. 2021

ACS Appl. Mater. Interfaces

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This work investigates the effect of partially hydrophobic grafted polymers on flocculation and dewatering of oil sands mature fine tailings. Here, we combine confocal microscopy and rheology to investigate how the graft density of ethylene-propylene-diene grafted with hydrolyzed poly(methyl acrylate) (EPDM-g-HPMA) affects its dispersion in water and flocculation efficiency in terms of sediment solids content and long-term dewatering of oil sands tailings. Increasing the graft density from 30 to 50% makes the flocculant easier to disperse, increases the rate of initial dewatering, and also enhances the viscoelastic response of the flocculated sediments. Conversely, the long-term rheological properties of the flocculated sediments were similar for all flocculants. Tri-dimensional microscopic details of the spatial distribution of water within the flocculated sludge provide novel insights into the performance of the flocculants. Increasing the graft density in EPDM-g-HPMA traps more water within the individual flocs and, consequently, decreases the post-flocculation dewatering rate. Our systematic approach confirms the importance of the spatial distribution of water in the flocculated sediment, which depends on how the flocculant is dispersed and how it retains water in the flocs.

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“…Currently, there is growing interest, especially in the oil industry, in the synthesis of hydrosoluble acrylamide-derivative co-or terpolymers with high molecular weights which are stable at high temperatures in the presence of saline media. [1][2][3][4][5][6] The synthesis of these macromolecules can be achieved by different synthesis methods such as aqueous solution polymerization, 7-10 mass polymerization, and inverse microemulsion polymerization. 11,12 Nonetheless, each method features a series of advantages and disadvantages that have to be considered.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis of water-soluble ionic terpolymers by inverse microemulsion and solution polymerization methods

et al. 2022

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Enhanced dewatering of oil sands tailings by a novel water-soluble cationic polymer

Cited by 16 publications

References 23 publications

Cationic Fluoropolyphosphazenes: Synthesis and Assembly with Heparin as a Pathway to Hemocompatible Nanocoatings

Cationic Fluoropolyphosphazenes: Synthesis and Assembly with Heparin as a Pathway to Hemocompatible Nanocoatings

Flocculation Efficiency and Spatial Distribution of Water in Oil Sands Tailings Flocculated with a Partially Hydrophobic Graft Copolymer

Synthesis of water-soluble ionic terpolymers by inverse microemulsion and solution polymerization methods

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