The agglomeration of high molecular mass polyacrylamide in aqueous solutions

Hecker, R. J.; Fawell, Phillip D.; Jefferson, Alan

doi:10.1002/(sici)1097-4628(19981212)70:11<2241::aid-app18>3.0.co;2-7

Cited by 16 publications

(8 citation statements)

References 22 publications

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“…From Figure 6, R g increased at higher pH* values. In a more acidic medium, HPAM had protonated acrylate anions; this consequently reduced the number of intramolecular bonds36 and reduced R g 43. The values of R g of 20–25 μm at pH* 3.0–3.5 and 120–170 μm at pH* 6.5–7.0 (Figure 6) suggested that there was a high agglomeration of polymer molecules; this was consistent with those reported by Hecker et al,43 who evaluated, by light scattering, the distribution of the R g of HPAM in deionized water with the addition of salts and organic cosolvents with mean values of 0.4 μm to individual polymer molecules.…”

Section: Resultssupporting

confidence: 86%

“…After IP, the acrylate anion {[CH(COO) − CH 2 ]} behaved as a branched polymer,45 and R g varied nonlinearly as a function of pH*. This behavior suggested that the anion interacted with acrylamide and protonated water,43 as reported for other polymer systems 46. In this pH* range, cation–anion bonds stabilized the bulb [ K 2 > K 1 (Table II)]; this reduced the rate of increase of R g with increasing pH*.…”

Section: Resultsmentioning

confidence: 67%

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Determination of the critical concentration of partially hydrolyzed polyacrylamide by potentiometry in an acidic medium

Gomes

Costa

2012

J of Applied Polymer Sci

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The literature presents different methods for quantifying and characterizing partially hydrolyzed polyacrylamide (HPAM) in solution. However, only a few of these are suitable for determining the critical overlap concentration (C \ ). The evaluation of C \ is important for describing the transition from the dilute to the semidilute regime, that is, when the solution depicts a characteristic viscosity at concentrations above C \ . This article describes the determination of C \ for HPAM in solution by potentiometry. The molecular weight, degree of hydrolysis, and polymerization degree are determined by mathematical manipulation of the constant of formation of aggregates, which is based on the law of mass action. The potentiometric curves were initially linear; asymptotic behavior followed. The inflection point was determined by the intersection, and the resulting equation of mathematical development statistically satisfied the experimental data and described the number of moles of monomers, the equilibrium constant for the formation of the aggregate, C \ , and the acidity constant of the polymer. The results for C \ , the degree of copolymerization, and the molecular weight proved that this method is a good alternative for the characterization of polymers with ionizable monomers and that are soluble in water.

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Section: Resultssupporting

confidence: 86%

Section: Resultsmentioning

confidence: 67%

Determination of the critical concentration of partially hydrolyzed polyacrylamide by potentiometry in an acidic medium

Gomes

Costa

2012

J of Applied Polymer Sci

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“…The conformations of the phPAA-FITC molecules were dynamically tracked under epi-fluorescence illumination at De = 41.46 (1 ml/h) and 414.6 (10 ml/h). Here, the observed phPAA-FITC molecules were polymer aggregates; this occurs naturally even at dilute concentrations 21 22 . Details of the molecular imaging setup have been included in the Methods section.…”

Section: Resultsmentioning

confidence: 75%

“…32 × 22 μm (β/α = 1.5), which was obtained by measuring ≈1000 polymer molecules under static conditions. It should be noted that the size of a single PAA molecule 29 (5 × 10 6 g/mol) is ≈1–2 μm, and the larger molecular size observed is the result of molecular aggregation 21 22 . Supplementary Table S2 shows the size distribution of the molecules, which has been subcategorized into 100 μm 2 incremental size ranges.…”

Section: Methodsmentioning

confidence: 98%

Visualization of polymer relaxation in viscoelastic turbulent micro-channel flow

Tai

Lim

Lam

2015

Sci Rep

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In micro-channels, the flow of viscous liquids e.g. water, is laminar due to the low Reynolds number in miniaturized dimensions. An aqueous solution becomes viscoelastic with a minute amount of polymer additives; its flow behavior can become drastically different and turbulent. However, the molecules are typically invisible. Here we have developed a novel visualization technique to examine the extension and relaxation of polymer molecules at high flow velocities in a viscoelastic turbulent flow. Using high speed videography to observe the fluorescein labeled molecules, we show that viscoelastic turbulence is caused by the sporadic, non-uniform release of energy by the polymer molecules. This developed technique allows the examination of a viscoelastic liquid at the molecular level, and demonstrates the inhomogeneity of viscoelastic liquids as a result of molecular aggregation. It paves the way for a deeper understanding of viscoelastic turbulence, and could provide some insights on the high Weissenberg number problem. In addition, the technique may serve as a useful tool for the investigations of polymer drag reduction.

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“…y a un poids moléculaire ou une longueur de chaîne optimale pour l'efficacité de la floculation [15]. Ce graphique met en évidence une augmentation de Sa turbidité de la surverse en fonction de l'augmentation de la concentration du polymère.…”

Section: Stabilité Des Suspensions Colloïdalesunclassified

Étude sur la clarification d'une suspension de boue rouge et de liqueur Bayer par floculation /

Normandin¹

2005

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UIUQAC Mise en garde/AdviceAfin de rendre accessible au plus grand nombre le résultat des travaux de recherche menés par ses étudiants gradués et dans l'esprit des règles qui régissent le dépôt et la diffusion des mémoires et thèses produits dans cette Institution, l'Université du Québec à Chicoutimi (UQAC) est fière de rendre accessible une version complète et gratuite de cette oeuvre.Motivated by a desire to make the results of its graduate students' research accessible to all, and in accordance with the rules governing the acceptation and diffusion of dissertations and theses in this Institution, the Université du Québec à Chicoutimi (UQAC) is proud to make a complete version of this work available at no cost to the reader.L'auteur conserve néanmoins la propriété du droit d'auteur qui protège ce mémoire ou cette thèse. Ni le mémoire ou la thèse ni des extraits substantiels de ceux-ci ne peuvent être imprimés ou autrement reproduits sans son autorisation.The author retains ownership of the copyright of this dissertation or thesis. Neither the dissertation or thesis, nor substantial extracts from it, may be printed or otherwise reproduced without the author's permission. observées entre tes résultats obtenus par ce test et ceux obtenus pour tes decanteurs en usine. L'objectif principal de ce projet était de réduire la quantité de matières particulares en suspension dans la surverse à un niveau inférieur à oeux retrouvé actuellement en usine. Pour arriver à réaliser une étude comparative sur ia clarté d'une surverse, la méthodologie du test du cylindre a été optimisée afin de réduire la variabilité des mesures de vitesse de décantation pour des essais effectués dans les mêmes conditions expérimentales. L'optimisation de la méthodologie du test du cylindre a permis de réduire considérablement la variabilité des mesures de vitesse. Des écarts de 5% et moins sont maintenant obtenus pour des vitesses de sédimentation entre un polymère d'essai et un polymère témoin. Les essais de clarté ont été réalisés en deux parties : une première partie des essais a été effectuée aux conditions d'opération retrouvées en usine, au niveau des decanteurs secondaires ou laveurs, et la seconde partie des essais a été réalisée aux conditions d'opération retrouvées en usine, dans tes decanteurs à haut rendement (DHR). Les variables à l'étude sont le type d'agents de floculation, le dosage et la séquence 3. Réduire la quantité de matières particulaires en suspension dans la surverse à un niveau inférieur à ceux retrouvés actuellement en usine.

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The agglomeration of high molecular mass polyacrylamide in aqueous solutions

Cited by 16 publications

References 22 publications

Determination of the critical concentration of partially hydrolyzed polyacrylamide by potentiometry in an acidic medium

Determination of the critical concentration of partially hydrolyzed polyacrylamide by potentiometry in an acidic medium

Visualization of polymer relaxation in viscoelastic turbulent micro-channel flow

Étude sur la clarification d'une suspension de boue rouge et de liqueur Bayer par floculation /

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