Temperature responsive flocculation and solid–liquid separations with charged random copolymers of poly(N-isopropyl acrylamide)

O'Shea, John-Paul; Qiao, Greg G.; Franks, George V.

doi:10.1016/j.jcis.2011.04.013

Cited by 56 publications

(46 citation statements)

References 38 publications

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“…This was attributed to interparticle forces in the sediment, switching from attractive (hydrophobic attraction above LCST) to repulsive (steric repulsion below LCST), causing the aggregate structures to rearrange and forcing water out of the sediments. In other words, the compressive yield stress of the sediments was now low enough to allow the bed to collapse due to gravitational forces, forcing the water out of the aggregate network . Figure shows a schematic of the proposed mechanism.…”

Section: Recent Advances In the Development Of Water Soluble Flocculantsmentioning

confidence: 99%

“…O'Shea et al. synthesized a series of random cationic poly(NIPAM‐ co ‐dimethylaminoethyl acrylate quaternary chloride) poly(NIPAM‐ co ‐DQA) and anionic poly(NIPAM‐ co ‐AA) to induce selective flocculation of silica and alumina, respectively . They observed that the counter‐charge flocculants adsorbed to the particles at temperatures above LCST, induced aggregation by charge neutralization, but no secondary consolidation was observed when cooling the suspension below LCST.…”

Section: Recent Advances In the Development Of Water Soluble Flocculantsmentioning

confidence: 99%

See 1 more Smart Citation

Water Soluble Polymer Flocculants: Synthesis, Characterization, and Performance Assessment

Vajihinejad

Gumfekar

Bazoubandi

et al. 2018

Macro Materials & Eng

135

108

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Water soluble polymer flocculants are important constituents of solid–liquid separation units for the treatment of a variety of process‐affected effluents. The systematic development of a flocculant relies on a good understanding of flocculation process, polymer synthesis, polymer characterization, and, not the least, flocculation performance assessment as desired for a particular treatment process, all of which are essential to establish meaningful relationships between flocculant microstructure and flocculation efficiency. The aim of this article is to communicate the bigger picture of this research area to the readers. The recent advances in the application of bio/natural, synthetic, and stimuli‐responsive flocculants are reviewed. Then, the basic polymer reaction engineering tools to control the microstructure of flocculants are provided and the techniques for the quantification of flocculant microstructure are concisely discussed. This is followed by a review of the methods used for the characterization of particle‐polymer force measurement, and flocculation/dewatering assessment with attention to the characterization of aggregate structures.

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Section: Recent Advances In the Development Of Water Soluble Flocculantsmentioning

confidence: 99%

Section: Recent Advances In the Development Of Water Soluble Flocculantsmentioning

confidence: 99%

Water Soluble Polymer Flocculants: Synthesis, Characterization, and Performance Assessment

Vajihinejad

Gumfekar

Bazoubandi

et al. 2018

Macro Materials & Eng

135

108

View full text Add to dashboard Cite

show abstract

“…Most of the smart polymers are environmentally responsive, including poly-(methacrylic acid), poly-(4-vinylpyridine) (Kan et al 2013), poly-(N-isopropyl-acrylamide) (Zoppe et al 2010), poly-(N,N-dimethylaminoethyl methacrylate) (Yi et al 2009), poly-(2-hydroxyethyl methacrylate), and poly-(ethylene glycol) methacrylates (Porsch et al 2011). Of these smart materials, temperature-responsive poly-(N-isopropyl acrylamide) PNIPAM has been widely studied and applied (Binkert et al 1991;O'Shea et al 2011). It exhibits lower critical solution temperatures (LCST) in the range of 32 °C to 33 °C, depending on the detailed microstructure of the macromolecules.…”

Section: Introductionmentioning

confidence: 99%

Temperature-Sensitive, Fluorescent Poly(N-Isopropyl-acrylamide)-Grafted Cellulose Nanocrystals for Drug Release

Wu¹,

Li²,

Liu³

et al. 2016

BioResources

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Cellulose nanocrystals (CNCs) grafted with fluorescent and thermoresponsive poly (N-isopropylacryalamide) (PNIPAM) brushes were prepared for encapsulation and the release of 5-fluorouracil (5-FU). The successful grafting was evidenced by Fourier transform infrared (FTIR) spectroscopy and solid-state 13C nuclear magnetic resonance ( 13 C NMR). Differential scanning calorimetry measurements suggested that the lower critical solution temperature of PNIPAM-grafted CNCs is close 32 °C. During polymerization, tuned fluorescence signatures were obtained by varying the dye dosages. At room temperature, the release amount of the loaded 5-FU was about 42% at a pH of 2.1, while this value approached 60% at a pH of 7.4. Both the cumulative release amount and the release rate were greatly increased when the temperature was raised to 37 °C. The novel PNIPAM-grafted CNCs with both fluorescence and stimulisensitive properties possess potential for application in intelligent drug delivery systems.

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“…Flocculation conditioning is the most conventional method to increase sludge dewatering efficiency and is useful especially in the separation of sludge [1][2][3][4]. Therefore, many chemical conditioners including polyaluminum chloride (PAC), ferric chloride (FeCl 3 ), and cationic polyacrylamide (CPAM) have been used for the treatment of sludge [5][6][7][8][9][10][11]. However, these conventional conditioners are no longer sufficient because of the increases in the volume of generated sludge and the deterioration of characteristics of the sludge [12].…”

Section: Introductionmentioning

confidence: 99%

Properties of flocs in sludge conditioning by a novel amphoteric polymer with different anionic degrees

et al. 2016

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This paper aimed to examine how the amphoteric conditioner poly (acrylamide‐′acryloyloxyethyl trimethyl ammonium chloride −2‐acrylamido‐2‐methyl‐propane sulfonate) (PADA) with different anionic degrees (AD) affected the properties of sludge flocs in the conditioning. The floc properties were characterized by morphological parameters (floc size distribution, fractal dimension, specific surface area, and pore volume), physical properties (floc strength and surface charge density), and chemical constituents (Fe3+, Al3+ and extracellular polymeric substances (EPS), including the polymeric proteins and carbohydrates). The results of this investigation revealed that (1) morphological properties of flocs were associated with anionic degree, particularly in the range of 0–4%, where the anionic degree led to a shift of the particle size toward groupings of larger diameter, meanwhile better regularity and increased compactness of floc structure formed. (2) The introduction of the anionic groups indeed had bad effects on flocs in terms of its stability and charge neutralization, but the downtrend could be inhibited by adjusting the anionic degree of polymer to a reasonable level. (3) The dissolved EPS for sludge followed a role of decreasing firstly then increasing with increased anionic degree, but the content of bound EPS kept nearly constant. (4) The polymer with anionic groups had apparent effects on enrichment of metal ions. POLYM. ENG. SCI., 57:197–205, 2017. © 2016 Society of Plastics Engineers

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Temperature responsive flocculation and solid–liquid separations with charged random copolymers of poly(N-isopropyl acrylamide)

Cited by 56 publications

References 38 publications

Water Soluble Polymer Flocculants: Synthesis, Characterization, and Performance Assessment

Water Soluble Polymer Flocculants: Synthesis, Characterization, and Performance Assessment

Temperature-Sensitive, Fluorescent Poly(N-Isopropyl-acrylamide)-Grafted Cellulose Nanocrystals for Drug Release

Properties of flocs in sludge conditioning by a novel amphoteric polymer with different anionic degrees

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