1
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Naseri E, Ahmadi A. A review on wound dressings: Antimicrobial agents, biomaterials, fabrication techniques, and stimuli-responsive drug release. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111293] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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2
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Lv S, Peng W, Cao Y, Liu S, Wang W, Fan G, Huang Y, Song X. Synthesis and characterisation of a novel pH-sensitive flocculant and its flocculation performance. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118480] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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3
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Dey S, Roy A, Manna K, Pal S. The UCST phase transition of a dextran based copolymer in aqueous media with tunable thermoresponsive behavior. Polym Chem 2022. [DOI: 10.1039/d2py00626j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A hydrogen bonded UCST polymer has been developed by grafting of methacrylamide and acrylic acid on dextran via free radical polymerization.
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Affiliation(s)
- Shaon Dey
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM) Dhanbad-826004, India
| | - Arpita Roy
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM) Dhanbad-826004, India
| | - Kalipada Manna
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM) Dhanbad-826004, India
| | - Sagar Pal
- Department of Chemistry and Chemical Biology, Indian Institute of Technology (ISM) Dhanbad-826004, India
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4
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Kalyanaraman G, Rostami Najafabadi Z, Soares J, Trifkovic M. Flocculation Efficiency and Spatial Distribution of Water in Oil Sands Tailings Flocculated with a Partially Hydrophobic Graft Copolymer. ACS APPLIED MATERIALS & INTERFACES 2021; 13:43726-43733. [PMID: 34473464 DOI: 10.1021/acsami.1c12546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
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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Affiliation(s)
- Gayathri Kalyanaraman
- Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, 2500 University Drive, Calgary, Alberta T2N 1N4, Canada
| | - Zahra Rostami Najafabadi
- Department of Chemical and Materials Engineering, Donadeo Innovation Centre for Engineering, University of Alberta, 9211-116 Street NW, Edmonton, Alberta T6G 1H9, Canada
| | - João Soares
- Department of Chemical and Materials Engineering, Donadeo Innovation Centre for Engineering, University of Alberta, 9211-116 Street NW, Edmonton, Alberta T6G 1H9, Canada
| | - Milana Trifkovic
- Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, 2500 University Drive, Calgary, Alberta T2N 1N4, Canada
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5
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Effects of calcium chloride and poly(N,N-dimethylaminoethyl methacrylate) on the filtration rate of a bentonite suspension and the examination of the filtration mechanism. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Ng J, Osborn I, Harbottle D, Liu Q, Masliyah JH, Xu Z. Stimuli-Responsive Hybrid Polymer for Enhanced Solid-Liquid Separation of Industrial Effluents. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:6436-6443. [PMID: 31059240 DOI: 10.1021/acs.est.8b07074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In the current study, a novel stimuli-responsive hybrid polymer with aluminum hydroxide colloids incorporated into a cationic copolymer of N-isopropylacrylamide and N-[3-(dimethylamino)propyl]methacrylamide was synthesized to enhance the settling and filtration performance of fine clay suspensions. The conformation of the synthesized hybrid copolymer was shown to respond to changes in both temperature and pH. Compared with a cationic copolymer of similar structure without aluminum hydroxide colloids, settling and filtration rates were significantly enhanced using the hybrid copolymer, which is attributed to the synergy between the inorganic aluminum hydroxide cores and organic copolymer. While the ideal treatment protocol for the hybrid polymer involved the addition of the polymer at room temperature, followed by heating to 45 °C for enhanced settling and dewatering, the synergistic effect between colloidal cores and polymer also allowed the hybrid polymer to perform well when added at temperatures above the LCST, demonstrating the robustness of the hybrid polymer to the process environment. The ideal treatment protocol resulted in an optimal adsorption of polymer on clays before inducing a coil-globule transition to form large and dense flocs, resulting in a more porous filter cake.
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Affiliation(s)
- Jason Ng
- Department of Chemical and Materials Engineering , University of Alberta , Edmonton , Alberta T6G 1H9 , Canada
| | - Ian Osborn
- Department of Chemical and Materials Engineering , University of Alberta , Edmonton , Alberta T6G 1H9 , Canada
| | - David Harbottle
- School of Chemical and Process Engineering , University of Leeds , Leeds LS2 9JT , U.K
| | - Qingxia Liu
- Department of Chemical and Materials Engineering , University of Alberta , Edmonton , Alberta T6G 1H9 , Canada
| | - Jacob H Masliyah
- Department of Chemical and Materials Engineering , University of Alberta , Edmonton , Alberta T6G 1H9 , Canada
| | - Zhenghe Xu
- Department of Chemical and Materials Engineering , University of Alberta , Edmonton , Alberta T6G 1H9 , Canada
- Department of Materials Science and Engineering , Southern University of Science and Technology , Shenzhen 518055 , China
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7
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Tan S, Saito K, Hearn MTW. Stimuli-responsive polymeric materials for separation of biomolecules. Curr Opin Biotechnol 2018; 53:209-223. [DOI: 10.1016/j.copbio.2018.02.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 02/12/2018] [Accepted: 02/12/2018] [Indexed: 10/17/2022]
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8
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Kato D, Sohn WY, Katayama K. Aggregation-Induced Expansion of Poly-( N-isopropyl acrylamide) Solutions Observed Directly by the Transient Grating Imaging Technique. ACS OMEGA 2018; 3:8484-8490. [PMID: 31458976 PMCID: PMC6645113 DOI: 10.1021/acsomega.8b01241] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 07/19/2018] [Indexed: 06/01/2023]
Abstract
The anomalous volume expansion of poly-(N-isopropyl acrylamide) (PNIPAM) solutions was observed during the thermally induced polymer phase transition of aqueous solutions having concentrations in the 3-7 wt % range. The process occurred on a millisecond time scale, and a laser temperature-jump time-resolved technique was used to bring about the process. After heating a solution with a pulse laser exploiting light absorption by dyes added to the solution itself, a phase transition was observed to take place, and the temporal changes associated with it were visualized through the transient grating imaging technique, whereby the solution was heated with a stripe pattern. We found several processes occurring on a millisecond time scale, all of which clearly took place after each PNIPAM molecule had collapsed structurally from a coiled to a globular conformation. During the so-called demixing process, the globular polymers aggregated with each other within 10 ms, and suddenly the polymer phase expanded as aggregation progressed further. After this process, the individual globular polymers reverted to their coiled conformation via hydration during the remixing process. We proposed that solution expansion was caused by the mutual entangling of multiple globular PNIPAM molecules, instead each globule polymer was separated.
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Affiliation(s)
- Daiki Kato
- Department
of Applied Chemistry, Chuo University, Tokyo 112-8551, Japan
| | - Woon Yong Sohn
- Department
of Applied Chemistry, Chuo University, Tokyo 112-8551, Japan
| | - Kenji Katayama
- Department
of Applied Chemistry, Chuo University, Tokyo 112-8551, Japan
- PRESTO,
Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
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9
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Sung Ng W, Connal LA, Forbes E, Mohanarangam K, Franks GV. In situ study of aggregate sizes formed in chalcopyrite-quartz mixture using temperature-responsive polymers. ADV POWDER TECHNOL 2018. [DOI: 10.1016/j.apt.2018.04.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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10
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Wilts EM, Herzberger J, Long TE. Addressing water scarcity: cationic polyelectrolytes in water treatment and purification. POLYM INT 2018. [DOI: 10.1002/pi.5569] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Emily M Wilts
- Department of Chemistry; Macromolecules Innovation Institute, Virginia Tech; Blacksburg USA
| | - Jana Herzberger
- Department of Chemistry; Macromolecules Innovation Institute, Virginia Tech; Blacksburg USA
| | - Timothy E Long
- Department of Chemistry; Macromolecules Innovation Institute, Virginia Tech; Blacksburg USA
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11
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Gumfekar SP, Soares JBP. A novel hydrophobically-modified polyelectrolyte for enhanced dewatering of clay suspension. CHEMOSPHERE 2018; 194:422-431. [PMID: 29227890 DOI: 10.1016/j.chemosphere.2017.12.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/26/2017] [Accepted: 12/02/2017] [Indexed: 06/07/2023]
Abstract
This work investigates the effect of multifunctional poly (N-isopropyl acrylamide/acrylic acid/N-tert-butylacrylamide) [p(NIPAM-AA-NTBA)] ternary polymer on the sedimentation of kaolin clay - a major fraction of oil sands tailings. A series of linear, uncross-linked p(NIPAM), p(NIPAM/AA), and p(NIPAM/AA/NTBM) were synthesized as random copolymers, where all monomer units were randomly arranged along the polymer backbone and connected by covalent bonds. The ternary copolymer, used as a flocculant, exhibited thermo-sensitivity, anionic nature, and hydrophobic association due to NIPAM, AA, and NTBM, respectively. As the ternary polymer is thermosensitive, it undergoes extended to coil-like conformation, i.e. hydrophilic to hydrophobic transition, above its lower critical solution temperature (LCST). The comonomers NIPAM (above LCST) and NTBM help expel water out of sediments due to their hydrophobicity, while AA promotes charge neutralization of the kaolin clay particles. The effect of number average molecular weight, charge density, and concentration of NTBM on settling behavior of kaolin suspension was examined. Settling test at 50 °C resulted in significantly higher settling rates compared to that at room temperature. Further, the quality of water recovered in each experiment was tested in terms of its turbidity. These results indicate that this novel ternary polymer can be employed to enhance the recovery of water from oil sands tailings containing clays.
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Affiliation(s)
- Sarang P Gumfekar
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada.
| | - João B P Soares
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada.
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12
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Gumfekar SP, Rooney TR, Hutchinson RA, Soares JBP. Dewatering Oil Sands Tailings with Degradable Polymer Flocculants. ACS APPLIED MATERIALS & INTERFACES 2017; 9:36290-36300. [PMID: 28945965 DOI: 10.1021/acsami.7b10302] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We synthesized hydrolytically degradable cationic polymers by micellar radical polymerization of a short-chain polyester macromonomer, polycaprolactone choline iodide ester methacrylate (PCL2ChMA) with two polyester units, and used them to flocculate oil sands mature fine tailings (MFT). We evaluated the flocculation performance of the homopolymer and copolymers with 30 mol % acrylamide (AM) by measuring initial settling rate (ISR), supernatant turbidity, and capillary suction time (CST) of the sediments. Flocculants made with trimethylaminoethyl methacrylate chloride (TMAEMC), the monomer corresponding to PCLnChMA with n = 0, have improved performance over poly(PCL2ChMA) at equivalent loadings due to their higher charge density per gram of polymer. However, MFT sediments flocculated using the PCL2ChMA-based polymers are easier to dewater (up to an 85% reduction in CST) after accelerated hydrolytic degradation of the polyester side chains. This study demonstrates the potential of designing cationic polymers that effectively flocculate oil sands tailings ponds, and also further dewater the resulting solids through polymer degradation.
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Affiliation(s)
- Sarang P Gumfekar
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2V4, Canada
| | - Thomas R Rooney
- Department of Chemical Engineering, Queen's University , Kingston, Ontario K7L 3N6, Canada
| | - Robin A Hutchinson
- Department of Chemical Engineering, Queen's University , Kingston, Ontario K7L 3N6, Canada
| | - João B P Soares
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2V4, Canada
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13
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Zhang D, Thundat T, Narain R. Flocculation and Dewatering of Mature Fine Tailings Using Temperature-Responsive Cationic Polymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:5900-5909. [PMID: 28514595 DOI: 10.1021/acs.langmuir.7b01160] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Temperature-responsive copolymer with cationic charge was prepared with N-isopropylacrylamide (NIPAm) and 2-aminoethyl methacrylamide hydrochloride (AEMA) by conventional free-radical polymerization. The flocculation performance of the copolymer, poly(AEMA-st-NIPAm), was compared to five different mixture ratios of polyNIPAm and cationic poly(acrylamide-st-diallyldimethylammonium chloride) (poly(AAm-st-DADMAC)). The effects of polymer mixture ratios, polymer dosages, and temperature on solid-liquid separation as a function of initial settling rates (ISR), supernatant turbidity, sediment solid content, and water recovery were investigated. Poly(NIPAm) can facilitate particles aggregation by bridging and hydrogen bonding under lower critical solution temperature (LCST); whereas, at temperature above LCST, the adsorption of poly(NIPAm) chains on particles can be enhanced by hydrophobic interaction. A two-step (25 °C → 50 °C → 25 °C) consolidation can further enhance the sediment solid content by polyNIPAm. While the neutral property of polyNIPAm resulted in high turbidity of supernatant, mixing with poly(AAm-st-DADMAC) increases the clarity of supernatant by neutralization of fine particles. The copolymer poly(AEMA-st-NIPAm) functions as a polyelectrolyte to enhance the polymer adsorption onto particles via electrostatic interactions, thus further improving ISR and supernatant clarity.
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Affiliation(s)
- Dan Zhang
- Department of Chemical and Materials Engineering, Donadeo Innovation Centre in Engineering , Edmonton, Alberta T6G 1H9, Canada
| | - Thomas Thundat
- Department of Chemical and Materials Engineering, Donadeo Innovation Centre in Engineering , Edmonton, Alberta T6G 1H9, Canada
| | - Ravin Narain
- Department of Chemical and Materials Engineering, Donadeo Innovation Centre in Engineering , Edmonton, Alberta T6G 1H9, Canada
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14
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Qi L, You X, Cheng JH, Hu YY. Properties of flocs in sludge conditioning by a novel amphoteric polymer with different anionic degrees. POLYM ENG SCI 2017. [DOI: 10.1002/pen.24401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Liang Qi
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology; Guangzhou 510006 China
| | - Xia You
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology; Guangzhou 510006 China
| | - Jian-Hua Cheng
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology; Guangzhou 510006 China
| | - Yong-You Hu
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology; Guangzhou 510006 China
- State Key Lab of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology; Guangzhou 510640 China
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15
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Ng WS, Connal LA, Forbes E, Mohanarangam K, Franks GV. In situ investigation of aggregate sizes formed using thermo-responsive polymers: Effect of temperature and shear. J Colloid Interface Sci 2017; 494:139-152. [PMID: 28157632 DOI: 10.1016/j.jcis.2017.01.067] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 01/19/2017] [Accepted: 01/19/2017] [Indexed: 01/30/2023]
Abstract
Temperature-responsive flocculants, such as poly(N-isopropylacrylamide) (PNIPAM), induce reversible particle aggregation upon heating above a lower critical solution temperature (LCST). The aim of this work is to investigate the aggregation of ground iron ore using PNIPAM and conventional polyacrylamide (PAM) flocculants in a continuously-sheared suspension, through in situ chord length measurements using Focused Beam Reflectance Measurement techniques and real-time imaging of the particle aggregates. In the presence of uncharged PNIPAM, particle aggregation occurs only upon heating to the LCST, and the aggregates continue to grow with further heating. Subsequent cooling re-disperses the aggregates, and repeated heating causes reformation. Unlike uncharged PNIPAM, anionic PNIPAM produces aggregates at temperatures below the LCST due to the polymer chains binding to two different particles via attractive interactions between the acrylic acid groups and the hematite surfaces, and can be added at temperatures above the LCST due to the formation of charge-stabilised micelles. Under continuous shear, the flocculant most able to resist aggregate size reduction was anionic PAM, followed by PAM, anionic PNIPAM, PNIPAM (6MDa), and PNIPAM (122kDa). Reversible aggregate breakage was found with all samples, except with PNIPAM (6MDa) after being subjected to shear rates above 550s-1. Furthermore, heating of the PNIPAM-dosed suspensions at shear rates below 200s-1 produced larger and more breakage-resistant aggregates.
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Affiliation(s)
- Wei Sung Ng
- Chemical and Biomolecular Engineering, University of Melbourne, Parkville, VIC 3010, Australia; CSIRO Mineral Resources, Clayton, VIC 3168, Australia.
| | - Luke A Connal
- Chemical and Biomolecular Engineering, University of Melbourne, Parkville, VIC 3010, Australia.
| | | | | | - George V Franks
- Chemical and Biomolecular Engineering, University of Melbourne, Parkville, VIC 3010, Australia.
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16
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Lu H, Xiang L, Cui X, Liu J, Wang Y, Narain R, Zeng H. Molecular Weight Dependence of Synthetic Glycopolymers on Flocculation and Dewatering of Fine Particles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11615-11622. [PMID: 27741575 DOI: 10.1021/acs.langmuir.6b03072] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this study, poly(2-lactobionamidoethyl methacrylamide) of various molecular weights (MWs) was synthesized using conventional free-radical polymerization. The effect of MW and polymer dosage on the settling rate of kaolin particles, turbidity of the supernatant, mud-line position, and solid content was investigated to determine the flocculation performance. The interaction forces, polymer conformation, particle sizes, and MWs were determined using several techniques, including surface forces apparatus, atomic force microscopy (AFM), dynamic light scattering, and gel permeation chromatography. Our results reveal that the initial settling rate of kaolin particles and the clarity of supernatants increase with increasing MW of the glycopolymers. Surface force measurements and AFM imaging of the adsorbed polymer surfaces show strong polymer-particle adhesion and bridging attraction between the glycopolymers and clay surfaces, which increase with increasing MW of the glycopolymer. The strengthened bridging attraction with the polymer MW is attributed to the formation of stronger adhesion (e.g., via hydrogen bonding) between the fine particles and the abundant hydroxyl groups in the glycopolymers of higher MW, thus contributing to enhanced flocculation behaviors. Our results provide new insights into the development of eco-friendly polymer flocculants based on glycopolymers for an efficient solid-liquid separation in tailing treatment and into the fundamental understanding of associated intermolecular interactions and flocculation mechanisms.
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Affiliation(s)
- Han Lu
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
| | - Li Xiang
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
| | - Xin Cui
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
| | - Jing Liu
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
| | - Yinan Wang
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
| | - Ravin Narain
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
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17
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Lu Q, Yan B, Xie L, Huang J, Liu Y, Zeng H. A two-step flocculation process on oil sands tailings treatment using oppositely charged polymer flocculants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 565:369-375. [PMID: 27179318 DOI: 10.1016/j.scitotenv.2016.04.192] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 04/29/2016] [Accepted: 04/29/2016] [Indexed: 06/05/2023]
Abstract
Water management and treatment of mineral tailings and oil sands tailings are becoming critical challenges for the sustainable development of natural resources. Polymeric flocculants have been widely employed to facilitate the flocculation and settling of suspended fine solid particles in tailings, resulting in the separation of released water and solid sediments. In this study, a new flocculation process was developed for the treatment of oil sands tailings by using two oppositely charged polymers, i.e. an anionic polyacrylamide and a natural cationic biopolymer, chitosan. The new process was able to not only improve the clarity of supernatant after settling but also achieve a high settling efficiency. Treatment of the oil sands tailings using pure anionic polyacrylamide showed relatively high initial settling rate (ISR) of ~10.3m/h but with poor supernatant clarity (>1000NTU); while the treatment using pure cationic polymer resulted in clear supernatant (turbidity as low as 22NTU) but relatively low ISR of >2m/h. In the new flocculation process, the addition of anionic polyacrylamide to the tailings was followed by a cationic polymer, which showed both a high ISR (~7.7m/h) and a low turbidity (71NTU) of the supernatant. The flocculation mechanism was further investigated via the measurements of floc size, zeta potential and surface forces. The new flocculation process was revealed to include two steps: (1) bridging of fine solids by anionic polyacrylamide, and (2) further aggregation and flocculation mediated by charge neutralisation of the cationic polymer, which significantly eliminated the fine solids in the supernatants as well as increases floc size. Our results provide insights into the basic understanding of the interactions between polymer flocculants and solid particles in tailings treatment, as well as the development of novel tailings treatment technologies.
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Affiliation(s)
- Qiuyi Lu
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4, Canada
| | - Bin Yan
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4, Canada
| | - Lei Xie
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4, Canada
| | - Jun Huang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4, Canada
| | - Yang Liu
- Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 2W2, Canada
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4, Canada.
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18
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Lu H, Wang Y, Li L, Kotsuchibashi Y, Narain R, Zeng H. Temperature- and pH-Responsive Benzoboroxole-Based Polymers for Flocculation and Enhanced Dewatering of Fine Particle Suspensions. ACS APPLIED MATERIALS & INTERFACES 2015; 7:27176-27187. [PMID: 26592529 DOI: 10.1021/acsami.5b09874] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Random copolymers based on N-isopropylacrylamide (NIPAAm) containing 2-aminoethyl methacrylamide hydrochloride (AEMA) and 5-methacrylamido-1,2-benzoboroxole (MAAmBo) were synthesized and subsequently evaluated for their performance in solid-liquid separation at various pH and temperatures. The strong interactions between benzoboroxole residues and kaolin hydroxyl groups were evaluated for the first time in the flocculation of fine particle suspensions. The lower critical solution temperatures (LCSTs) of PAMN decreases because of the hydrophobic nature of the benzoboroxole moieties, resulting in strong hydrophobic interaction at temperatures higher than the LCSTs. Temperature and pH responsive polymer, P(AEMA51-st-MAAmBo76-st-NIPAM381) (denoted as PAMN) shows the ability to induce fastest settling at a low dosage of 25 ppm and under the condition of pH 9 and 50 °C. The accelerated settling rate is considered to be due to the strong adhesion of benzoboroxole residues to the kaolin hydroxyl groups, the electrical double layer force, and the hydrophobic force. During condensation phase, increasing the pH of sediment to pH 11 could attain the most compact structure. Random copolymers containing benzoboroxole groups act as dispersants (due to pH-responsive character) rather than flocculants at pH 11, providing repulsive force that enables particles to rearrange their position and consolidate well. Through a two-step solid-liquid separation including settling phase and consolidation phase, rapid settling and compact sediment are feasible simultaneously.
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Affiliation(s)
- Han Lu
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
| | - Yinan Wang
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
| | - Lin Li
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
| | - Yohei Kotsuchibashi
- International Center for Young Scientists (ICYS), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Japan
| | - Ravin Narain
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, Alberta T6G 2G6, Canada
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Qi L, Cheng JH, Liang XY, Hu YY. Synthesis and characterization of a novel terpolymer and the effect of its amphoteric property on the sludge flocculation. POLYM ENG SCI 2015. [DOI: 10.1002/pen.24238] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Liang Qi
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy; South China University of Technology; Guangzhou 510006 China
| | - Jian-Hua Cheng
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy; South China University of Technology; Guangzhou 510006 China
| | - Xiao-Yan Liang
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy; South China University of Technology; Guangzhou 510006 China
| | - Yong-You Hu
- Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy; South China University of Technology; Guangzhou 510006 China
- State Key Lab of Pulp and Paper Engineering; College of Light Industry and Food Science, South China University of Technology; Guangzhou 510640 China
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Beattie DA, Addai-Mensah J, Beaussart A, Franks GV, Yeap KY. In situ particle film ATR FTIR spectroscopy of poly (N-isopropyl acrylamide) (PNIPAM) adsorption onto talc. Phys Chem Chem Phys 2015; 16:25143-51. [PMID: 25330994 DOI: 10.1039/c4cp03161j] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The adsorption of poly(N-isopropyl acrylamide) (PNIPAM) onto talc from aqueous solutions has been studied using the in situ methodology of particle film attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy. PNIPAM was observed to adsorb significantly onto the talc particle film at a temperature below its lower critical solution temperature (LCST). Peak shifts were seen in the adsorbed layer FTIR spectrum that match those observed when PNIPAM solution is heated above its LCST. This observation indicates that adsorption causes a conformational re-arrangement similar to that seen when PNIPAM undergoes a coil-to-globule transition, in this case presumably induced by hydrophobic interactions between PNIPAM and the talc basal plane surface. The kinetics of adsorption are seen to be complex, with potential influences of conformational rearrangement and differential adsorption kinetics for the two dominant surface regions of talc particles. The adsorbed PNIPAM was seen to be exceptionally resistant to removal, with no desorption occurring when a background electrolyte solution was flowed over the adsorbed layer. Spectra acquired of the adsorbed polymer layer heated above the LCST reveal that a further conformational rearrangement takes place for the adsorbed layer, finalizing the transition from coil-to-globule that was initiated by the interaction with the mineral surface.
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Affiliation(s)
- David A Beattie
- Ian Wark Research Institute, University of South Australia, Mawson Lakes SA 5095, Australia.
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22
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Oyeneye OO, Xu WZ, Charpentier PA. Adhesive RAFT agents for controlled polymerization of acrylamide: effect of catechol-end R groups. RSC Adv 2015. [DOI: 10.1039/c5ra16193b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Synthesizing polyacrylamide (PAM) inorganic nanocomposites with stable tethering and controlled polymer length has been elusive.
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Affiliation(s)
- Olabode O. Oyeneye
- Department of Chemical and Biochemical Engineering
- University of Western Ontario
- London
- Canada
| | - William Z. Xu
- Department of Chemical and Biochemical Engineering
- University of Western Ontario
- London
- Canada
| | - Paul A. Charpentier
- Department of Chemical and Biochemical Engineering
- University of Western Ontario
- London
- Canada
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23
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Synthesis and electromechanical actuation of a temperature, pH, and electrically responsive hydrogel. JOURNAL OF POLYMER RESEARCH 2014. [DOI: 10.1007/s10965-014-0466-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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24
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Zhang Z, Zheng P, Cai D, An X, Shen W. Interaction of Ionic Surfactants with a Hydrophobic Modified Thermosensitive Polymer. J DISPER SCI TECHNOL 2014. [DOI: 10.1080/01932691.2013.805655] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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25
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Franks GV, O'Shea JP, Forbes E. Controlling thickener underflow rheology using a temperature responsive flocculant. AIChE J 2014. [DOI: 10.1002/aic.14469] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- George V. Franks
- Dept. of Chemical and Biomolecular Engineering; Australian Mineral Science Research Institute, University of Melbourne; Parkville Victoria 3010 Australia
| | - John-Paul O'Shea
- Dept. of Chemical and Biomolecular Engineering; Australian Mineral Science Research Institute, University of Melbourne; Parkville Victoria 3010 Australia
| | - Elizaveta Forbes
- Dept. of Chemical and Biomolecular Engineering; Australian Mineral Science Research Institute, University of Melbourne; Parkville Victoria 3010 Australia
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26
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Wang Y, Kotsuchibashi Y, Liu Y, Narain R. Temperature-responsive hyperbranched amine-based polymers for solid-liquid separation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:2360-2368. [PMID: 24533692 DOI: 10.1021/la5003012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Temperature-responsive hyperbranched polymers containing primary amines as pendent groups have been synthesized for solid-liquid separation of kaolinite clay suspension. The effects of temperature, polymer charge density, and polymer architecture on particle flocculation have been investigated. Suspensions treated with the temperature-responsive amine-based hyperbranched polymers showed remarkable separation of the fine particles at a low polymer dosage of 10 ppm and at testing temperatures of 40 °C. In comparison to other polymers studied (linear and hyperbranched homopolymers and copolymers), the temperature-responsive amine-based hyperbranched copolymers showed better particle flocculation at 40 °C, as evidenced by the formation of a thinner sediment bed without compromising the amount of clay particles being flocculated. This superior solid-liquid separation performance can be explained by the hydrophobic interaction of PNIPAM segments on particle surfaces or the capture of additional free particles or small floc due to the exposure of buried positive charges (because of the phase separation of the hydrophilic amines and hydrophobic PNIPAM part) at temperatures above the lower critical solution temperature (LCST).
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Affiliation(s)
- Yinan Wang
- Department of Chemical and Materials Engineering, University of Alberta , 116 Street and 85 Avenue, Edmonton, AB T6G 2G6, Canada
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27
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Lv S, Sun T, Zhou Q, Liu J, Ding H. Synthesis of starch-g-p(DMDAAC) using HRP initiation and the correlation of its structure and sludge dewaterability. Carbohydr Polym 2014; 103:285-93. [DOI: 10.1016/j.carbpol.2013.12.036] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/11/2013] [Accepted: 12/12/2013] [Indexed: 10/25/2022]
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28
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Thermal responsive hydrogels based on semi interpenetrating network of poly(NIPAm) and cellulose nanowhiskers. Carbohydr Polym 2014; 102:159-66. [DOI: 10.1016/j.carbpol.2013.10.054] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 10/05/2013] [Accepted: 10/11/2013] [Indexed: 11/23/2022]
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29
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Iritani E, Katagiri N, Washizu T, Hwang KJ, Cheng TW. Combined Effect of Reversible Flocculation and Ultrahigh Pressure in High-Level Deliquoring Attained by Expression of Activated Sludge. KAGAKU KOGAKU RONBUN 2014. [DOI: 10.1252/kakoronbunshu.40.396] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Eiji Iritani
- Department of Chemical Engineering, Nagoya University
| | | | | | - Kuo-Jen Hwang
- Department of Chemical and Materials Engineering, Tamkang University
| | - Tung-Wen Cheng
- Department of Chemical and Materials Engineering, Tamkang University
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30
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Combination of Natural and Thermosensitive Polymers in Flocculation of Fine Silica Dispersions. ACTA ACUST UNITED AC 2013. [DOI: 10.1155/2013/242684] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A novel strategy for faster and better flocculation in solid-liquid separation processes is reported: the use of the natural polyelectrolyte chitosan (CH2500) in combination with the biocompatible thermosensitive polymer poly(N-vinylcaprolactam) (PNVCL). Silica dispersions (Aerosil OX50) were used as model and evaluated by means of analytical centrifuge, laser diffraction, and turbidimetry studies. Results show that the sedimentation velocity is doubled by addition of PNVCL and that at 45°C the density of the sediment is 33% higher, as compared to the use of CH2500 only. This results from the temperature sensitive behavior of PNVCL that phase-separate expelling water at temperatures higher than its LCST (32–34°C) leading to compaction of the flocs. By using this strategy the sediment is more compact, contains less water, and contains a very small amount of biodegradable CH2500 and biocompatible PNVCL.
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31
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Yan X, Chai L, Li Q. Effect of Precipitant Additives on the Sludge Settling and Compacting Performance for Heavy Metal Wastewater Treatment. SEP SCI TECHNOL 2013. [DOI: 10.1080/01496395.2012.753083] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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32
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Sakohara S, Kawachi T, Gotoh T, Iizawa T. Consolidation of suspended particles by using dual ionic thermosensitive polymers with incorporated a hydrophobic component. Sep Purif Technol 2013. [DOI: 10.1016/j.seppur.2012.12.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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33
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Mori T, Tsubaki J, O'Shea JP, Franks GV. Hydrostatic pressure measurement for evaluation of particle dispersion and flocculation in slurries containing temperature responsive polymers. Chem Eng Sci 2013. [DOI: 10.1016/j.ces.2012.02.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lemanowicz M, Kuźnik W, Gibas M, Dzido G, Gierczycki A. Impact of heating method on the flocculation process using thermosensitive polymer. WATER RESEARCH 2012; 46:4091-4098. [PMID: 22658925 DOI: 10.1016/j.watres.2012.05.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 05/05/2012] [Accepted: 05/08/2012] [Indexed: 06/01/2023]
Abstract
The impact of suspension heating method on the flocculation process using thermosensitive polymer is reported in this paper. In experiments a model suspension of chalk in RO water (purified by Reverse Osmosis) was destabilized using a copolymer of N-isopropylacrylamide (NIPAM) and cationic diallyldimethyl ammonium chloride (DADMAC). The measurements were made using a laboratory setup consisting of a mixing tank with four baffles, Rushton turbine, laser particle sizer Analysette 22 by Fritsch and a system of pump and thermostating devices. Two different modes of heating were used. In the first case the temperature of the system was gently raised above the Lower Critical Solution Temperature (LCST) using an electrical heater placed inside the tank, while in the second case the system temperature was rapidly raised by an injection of hot water directly into the tank. It was proven that heating method as well as the polymer concentration was crucial to the shape and size of created flocs.
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Affiliation(s)
- Marcin Lemanowicz
- Department of Chemical and Process Engineering, Faculty of Chemistry, Silesian University of Technology, ul. ks. M. Strzody 7, 44-100 Gliwice, Poland.
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Yang Y, Mijalis AJ, Fu H, Agosto C, Tan KJ, Batteas JD, Bergbreiter DE. Reversible Changes in Solution pH Resulting from Changes in Thermoresponsive Polymer Solubility. J Am Chem Soc 2012; 134:7378-83. [DOI: 10.1021/ja211315e] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Yanfei Yang
- Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012, United States
| | - Alexander J. Mijalis
- Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012, United States
| | - Hui Fu
- Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012, United States
| | - Cynthia Agosto
- Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012, United States
| | - Kristine J. Tan
- Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012, United States
| | - James D. Batteas
- Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012, United States
| | - David E. Bergbreiter
- Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012, United States
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36
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Budgin AM, Kabachii YA, Shifrina ZB, Valetsky PM, Kochev SS, Stein BD, Malyutin A, Bronstein LM. Functionalization of magnetic nanoparticles with amphiphilic block copolymers: self-assembled thermoresponsive submicrometer particles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:4142-4151. [PMID: 22303838 DOI: 10.1021/la205056k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
For the first time the four block copolymers derived from 1-alkyl[2-(acryloyloxy)ethyl]dimethylammonium bromides with hexyl (ADA) or cetyl (ADHA) groups and 2-hydroxyethylacrylate (HEA) or N-isopropylacrylamide (NIPAM) were synthesized and employed for functionalization of monodisperse iron oxide nanoparticles (NPs). The polyADA (pADA) or polyADHA (pADHA) block consists of long hydrophobic tails (C(6) or C(16)) connected to a positively charged quaternary ammonium group, making this block amphiphilic. The second block was either fully hydrophilic (pHEA) or thermoresponsive (pNIPAM). The dependence of the NP coating on the length of the hydrophobic tail in the amphiphilic block, the composition of the hydrophilic block, and the NP sizes have been studied. Unusual self-assembling of iron oxide NPs into well-defined composite submicrometer particles was observed for pADHA-b-pNIPAM in the wide range of concentrations (at the pADHA repeating unit concentrations of 0.065 × 10(-2)-2.91 × 10(-2) mmol/mL per 1 mg/mL NPs) but only two concentrations, 1.62 × 10(-2) and 1.94 × 10(-2) mmol/mL, led to regular spherical particles. The thermoresponsive behavior of these composite particles was tested using ζ-potential and dynamic light scattering measurements, while the morphology of particles was characterized by transmission electron microscopy. Coating of NPs with pADHA-b-pHEA results in the formation of individually coated NPs. The different composite particle morphologies are explained by different properties of pHEA and pNIPAM. It is demonstrated that the composite particles based on pADHA-b-pNIPAM are responsive to a magnetic field and can be recommended as magnetic stoppers in biorelated membrane separations. The incorporation of Pd species in submicrometer particles makes them promising candidates for catalytic applications as magnetically recoverable catalysts with a high magnetic response.
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Affiliation(s)
- Angela M Budgin
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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O'Shea JP, Qiao GG, Franks GV. Temperature-responsive solid-liquid separations with charged block-copolymers of poly(N-isopropyl acryamide). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:905-913. [PMID: 22070408 DOI: 10.1021/la2038872] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Temperature responsive charged block-copolymers of poly(N-isopropylacrylamide) (PNIPAM) have been used in the solid-liquid separation of alumina mineral particles from aqueous solution. The effects of temperature, polymer charge-sign and fraction of charged segment have been investigated. Batch settling and adsorption studies showed that rapid sedimentation results for suspensions with polymers of opposite charge-sign to the particle surface-charge (counterionic) at 50 °C. Cooling the suspensions after flocculation at 50 °C was found to increase the final solids volume fraction of the sediment beds formed through a mechanism related to partial desorption of polymer and the reduction of the hydrophobic attraction. Suspension stability results after dosing with polymers of similar charge-sign to the particle surface-charge (co-ionic) at both 25 and 50 °C. Increasing the amount of polymer charge increased the influence of polymer charge-sign on the adsorption and solid-liquid separation behavior. The performance of the charged block copolymers are compared to that of the random charged copolymer and neutral homopolymer PNIPAM structures.
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Affiliation(s)
- John-Paul O'Shea
- Department of Chemical and Biomolecular Engineering, Australian Mineral Science Research Institute, The University of Melbourne, Victoria, 3010 Australia
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