Compaction of TiO2 suspension utilizing hydrophilic/hydrophobic transition of cationic thermosensitive polymers

Sakohara, Shuji; Nishikawa, Kazuo

doi:10.1016/j.jcis.2004.06.002

Cited by 48 publications

(33 citation statements)

References 11 publications

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“…On the other hand, ionic temperature‐sensitive polymers are greatly impacted by the polymer ionic content as well as solution pH. Sakohara et al observed that copolymerization of NIPAM with a cationic monomer (N,N‐dimethylaminopropylacrylamide, DMAPAA) produced a copolymer with higher LCST. As the cationic content increased from 0.23 to 19.6 mol%, the LCST of the polymer gradually raised from 32 to almost 70 °C, respectively.…”

Section: Polymeric Flocculants For Oil Sand Tailings Treatmentmentioning

confidence: 99%

Water‐soluble polymers for oil sands tailing treatment: A Review

2015

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Efficient dewatering of oil sands tailings is imperative to reduce the environmental footprint of oil sands operators. Currently there is no mature technology capable of effectively treating oil sands tailings and completely eliminating the use of tailings ponds. Consolidated tailings and paste technology are the most extensively used dewatering methods. However, the high concentrations of divalent ions in the water recovered using the consolidated tailings process impedes the re-utilization of this water in the bitumen extraction process. Accumulation of ions does not occur in the case of paste technology; however, this technology, similarly to the consolidated tailings process, recovers only part of the water from tailings and produces high-water content sediments (25-30 wt. % solids) that sill requires special storage. This happens because the sediments produced by polyacrylamide (PAM) flocculants are not closely packed and require the application of other consolidation technologies (e.g., freeze-thaw, filtration, centrifugation) to obtain dry and self-supportive tailings. This review focuses on examining alternative flocculants that could potentially replace PAM polymers in mature and new dewatering technologies. Flocculants are a key element of many tailing treatments including paste technology and filtration. The "ideal" flocculant would increase the ability of these technologies to dewater tailings, resulting in higher water recovery and sediment consolidation without affecting water chemistry or increasing operational costs. This review presents a comparison between PAM flocculants and two promising alternative flocculants: inorganic-organic hybrid and temperature-sensitive polymers. Each flocculant type is evaluated in terms of its flocculation mechanisms and its dewatering efficacy.

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Section: Polymeric Flocculants For Oil Sand Tailings Treatmentmentioning

confidence: 99%

Water‐soluble polymers for oil sands tailing treatment: A Review

2015

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“…Indeed, "salting-out" of the isopropyl groups in NIPAM has been correlated with the increase in surface tension caused by aqueous salt solutions. 31 An additional driving force for salt-induced dehydration of P[NIPAM] TCNGs is the increase in osmotic pressure gradient between the polymer phase and bulk solution phase with added electrolyte. However, as pointed out by Lopez-Leon and colleagues, cationic P[NIPAM]-based TCNGs undergo salt-induced dehydration at a rate far in excess of the rate of collapse predicted solely on the basis of osmotic effects (D h α C s n , where n = 0.2 for a purely osmotic-driven mechanism, whereas values of n = 1 were reported).…”

Section: Dovepressmentioning

confidence: 99%

Characterization of complexation of poly (N-isopropylacrylamide-co-2-(dimethylamino) ethyl methacrylate) thermoresponsive cationic nanogels with salmon sperm DNA

Moselhy

Vira²,

Liu³

et al. 2009

IJN

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Thermoresponsive cationic nanogel (TCNG) networks based on N-isopropylacrylamide (NIPAM), 2-(dimethylamino)ethyl methacrylate (DMAEMA), and quaternary alkyl ammonium halide salts of DMAEMA (DMAEMAQ) were synthesized by dispersion polymerization technique. The thermoresponsive properties of TCNGs and TCNG-salmon sperm DNA (sasDNA) polyplexes were characterized in aqueous media of various pH and ionic strength. The distinct phase-transition properties of P[NIPAM/DMAEMA]/sasDNA and P[NIPAM/ DMAEMAQ]/sasDNA polyplexes were attributed to the condensing capability of polycations and to differences in the spatial distribution of structural charges in quaternized and nonquaternized networks. The findings demonstrate that stable TCNGs can be prepared with controllable responsive properties determined by the nature of the cationic charge incorporated and may have potential as vehicles for DNA delivery.

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“…The ability of PNIPAM to undergo controlled transitions from hydrophobic to highly hydrophilic has sparked considerable interest in its suitability as a surface modification reagent in minerals processing. A large number of studies have found PNIPAM to be a highly successful agent for facilitating mineral aggregation and consolidation [9][10][11][12][13][14][15], however questions remain regarding PNIPAM-induced aggregation mechanisms. In typical settling operations, flocculation occurs as a result of polymer bridging between mineral particles, which causes them to form aggregates [16].…”

Section: Introductionmentioning

confidence: 99%