Swelling-contraction of sodium polyacrylate hydrogels in media with various pH values

Elyashevich, G. K.; Bel’nikevich, N. G.

doi:10.1134/s0965545x09050095

Cited by 25 publications

(12 citation statements)

References 9 publications

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“…in the degree of swelling for the ratio of 1 : 1.5 was probably due to the fact that the number of intermolecular crosslinks reached high values. It is known [6] that Q eq of polyelectrolyte gels depends on the degree of crosslinking and decreases with its rising.…”

Section: Methodsmentioning

confidence: 99%

Polymeric hydrogels based on polyhexamethylene guanidine hydrochloride and formaldehyde

2015

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Section: Methodsmentioning

confidence: 99%

Polymeric hydrogels based on polyhexamethylene guanidine hydrochloride and formaldehyde

2015

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“…Grade 1 has a water absorbent capacity 1.5 times greater than that of grade 2. According to the work done by [28], this could be due directly to the gradation of the polymer particles. Buffer solutions with pH in the range 1-13 were used to assess the pH sensitivity of SAP hydrogels.…”

Section: Sap Dosages Calculation and Expression For The Absorbency Pamentioning

confidence: 99%

“…Besides, their absorption capacity will depend on various physico-chemical parameters such as temperature, pH of the slurry, composition and concentration of the chemical elements in the tailings slurry, presence of salts and/or cations, etc. [18,[26][27][28]. The main objective of this paper is to assess the potential use of superabsorbent polymers (SAPs) for mine tailings slurry dewatering and to obtain densified tailings for surface storage.…”

Section: Introductionmentioning

confidence: 99%

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Dewatering of Mine Tailings Slurries Using Superabsorbent Polymers (SAPs) Reclaimed from Industrial Reject of Baby Diapers: A Preliminary Study

et al. 2019

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Traditional deposition of tailings slurry in a tailings storage facility (TSF) can create risks of dike failure. In order to minimize these risks and slurry spillage, the surface deposition technique of densified tailings (DT) through dewatering of the slurry has emerged. The DT technique has the potential to maximize water reuse, improve the shear strength of surface tailings, and reduce the ecological footprint of TSF. The consistency of DT covers a continuum ranging from thickened state, to paste state, to dry state. Despite its efficiency and economic feasibility, DT densification using thickeners sometimes proves unable to achieve the design target solids mass concentration (C w% ). Hence, the use of superabsorbent polymers (SAPs) seems to represent a promising alternative, owing to their higher water absorbent capacity. In this paper, superabsorbent polymers (SAPs) reclaimed from industrial reject of baby diapers (Na-polyacrylates) are explored as a promising alternative to mine tailings slurries dewatering. To this end, laboratory-scale dewatering tests have been performed using two grades of Na-polyacrylate SAPs (grade 1 SAP = SAG-A06P coarse-grained, and grade 2 = SAG-M01P-100 medium-grained) for the tailings slurries densification. A higher water absorbency (or swelling capacity) was observed using the coarser SAPs (SAG-A06P) compared to the finer SAPs (SAG-M01P-100). The preliminary results showed that a SAP volume dosage in the range 10-13 kg of SAP/m 3 of slurry allowed achieving a final solids mass concentration (C w%_final ) ≥ 70%, despite the occurrence of gel-blocking phenomenon.Minerals 2019, 9, 785 2 of 18 the slurry. The thickened tailings technology has the potential to maximize water reuse, improve the shear strength of surface tailings, and reduce the ecological footprint of TSF by taking up a smaller area and volume [9,10]. The consistency of dewatered-or densified-tailings covers a continuum ranging from slurry state to thickened state (like molasses), to paste state (like toothpaste), and finally to dry state (like soil) [11]. In the mining industry, this consistency is usually defined according to the pulp mass density or the solids mass concentration (C w% = 100 × M dry-tailings /M slurry ). Thus, the thickened tailings would have a final C w% of between 45% and 70%, the paste tailings with a final C w% of between 70% and 85%, and the dehydrated tailings with a final C w% of greater than 85% [11,12].When the operation is underground, an alternative or supplement to the surface storage would be returning to the voids created up to 50% of the tailings in the form of cemented paste backfill [1,10,[13][14][15]. When sulphide minerals in mine waste stored in surface are exposed to air and in the presence of water and their acid neutralization potential is not sufficient, or has been exhausted [1], these waste can produce acid mine drainage (AMD). Due to the stringent environmental regulations, these large amounts of wastes must be managed adequately. More often than not, the mining industry...

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“…They comprise a wide range of applications like for example hygiene products, pharmaceuticals, food additives, sensors, and biosensors [17,18]. For alkaline solutions, hydrogel electrolytes like cross-linked sodium polyacrylate [19][20][21], acidic polyvinyl alcohol/polyacrylic acid blend cross-linked with glutaraldehyde [22], or poly(acrylate-co-acrylamide) [23] have been studied. In this work, a flexible Hg|HgO|OH − reference electrode with poly(acrylic acid) partial Na-salt graftpoly(ethylene oxide) hydrogel immobilized electrolyte is presented.…”

Section: Introductionmentioning

confidence: 99%

Hydrogel-based flexible micro-reference electrodes for use in alkaline and neutral pH solutions

Schimo

Grill

Kollender

et al. 2016

J Solid State Electrochem

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Two types of nonbreakable, flexible microreference electrodes filled with gel-electrolytes were prepared for use in solutions with alkaline and neutral pH. The electrodes are intended for electrochemical measurements, in which chloride-free conditions are important. Due to the flexible, bendable construction of the electrodes, electrochemical experiments at locations difficult to access with common reference electrodes are enabled. Hg|HgO-type electrodes were prepared from amalgamated Au wires, followed by oxidation of the amalgam, which is mounted in a PTFE tube filled with 0.1M NaOH solution immobilized in a PAA-g-PEO gel. The potential of this type of electrode was found to be 0.162 ± 0.002 V (SHE) at room temperature. Cu|CuSO 4 electrodes, consisting of a Cu wire immersed in a saturated CuSO 4 solution jellied with gelatin, showed a stable open-circuit potential of 0.312 ± 0.001 V (SHE). Further characterization of the electrodes was performed in terms of electrochemical impedance spectroscopy and micro-polarization measurements. As an alternative to the flexible electrodes, rigid electrodes in glass enclosure were fabricated in analogy to the flexible-type electrodes.

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Swelling-contraction of sodium polyacrylate hydrogels in media with various pH values

Cited by 25 publications

References 9 publications

Polymeric hydrogels based on polyhexamethylene guanidine hydrochloride and formaldehyde

Polymeric hydrogels based on polyhexamethylene guanidine hydrochloride and formaldehyde

Dewatering of Mine Tailings Slurries Using Superabsorbent Polymers (SAPs) Reclaimed from Industrial Reject of Baby Diapers: A Preliminary Study

Hydrogel-based flexible micro-reference electrodes for use in alkaline and neutral pH solutions

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