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O'Bryan CS, Murdoch TJ, Strickland DJ, Rose KA, Bendejacq D, Lee D, Composto RJ. Investigating the Sequence Specific Adsorption Behavior of Polypeptides at the Solid/Liquid Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:1740-1749. [PMID: 36637895 DOI: 10.1021/acs.langmuir.2c02292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Polymer adsorption at the solid/liquid interface depends not only on the chemical composition of the polymer but also on the specific placement of the monomers along the polymer sequence. However, challenges in designing polymers with well-controlled sequences have limited explorations into the role of polymer sequence on adsorption behavior to molecular simulations. Here, we demonstrate how the sequence control offered by polypeptide synthesis can be utilized to study the effects small changes in polymer sequence have on polymer adsorption behavior at the solid/liquid interface. Through a combination of quartz crystal microbalance with dissipation monitoring and total internal reflection ellipsometry, we study the adsorption behavior of three polypeptides, consisting of 90% lysine and 10% cysteine, onto a gold surface. We find different mechanisms are responsible for the adsorption of polypeptides and the resulting conformation on the surface. The initial adsorption of the polypeptides is driven by electrostatic interactions between the polylysine and the gold surface. Once adsorbed, the cysteine undergoes a thiol-Au reaction with the surface, altering the conformation of the polymer layer. Our findings suggest the conformation of the polypeptide layer is dependent on the placement of the cysteines within the sequence; polypeptide chains with evenly spaced cysteine groups adopt a more tightly bound "train" conformation as compared to polypeptides with closely grouped cysteine groups. We envision that the methodologies presented here to study sequence specific adsorption behaviors using polypeptides could be a valuable tool to complement molecular simulations studies.
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Affiliation(s)
- Christopher S O'Bryan
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
- Department of Material Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - Timothy J Murdoch
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - Daniel J Strickland
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
- Department of Material Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - Katie A Rose
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - Denis Bendejacq
- Complex Assemblies of Soft Matter Laboratory, IRL 3254, Solvay USA Inc., Bristol, Pennsylvania19007, United States
| | - Daeyeon Lee
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
| | - Russell J Composto
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
- Department of Material Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
- Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania19104, United States
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2
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O'Bryan CS, Rosenfeld J, Zhang A, Keller AW, Bendejacq D, Kagan CR, Murray CB, Lee D, Composto RJ. Electrochemically deposited molybdenum disulfide surfaces enable polymer adsorption studies using quartz crystal microbalance with dissipation monitoring (QCM-D). J Colloid Interface Sci 2022; 614:522-531. [PMID: 35121510 DOI: 10.1016/j.jcis.2022.01.098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 12/21/2021] [Accepted: 01/16/2022] [Indexed: 11/16/2022]
Abstract
Polymer and small molecules are often used to modify the wettability of mineral surfaces which facilitates the separation of valuable minerals such as molybdenum disulfide (MoS2) from gangue material through the process of froth flotation. By design, traditional methods used in the field for evaluating the separation efficacy of these additives fail to give proper access to adsorption kinetics and molecule conformation, crucial aspects of flotation where contact times may not allow for full thermodynamic equilibrium. Thus, there is a need for alternative methods for evaluating additives that accurately capture these features during the adsorption of additives at the solid/liquid interface. Here, we present a novel method for preparing MoS2 films on quartz crystals used for Quartz Crystal Microbalance with Dissipation (QCM-D) measurements through an electrochemical deposition process. The resulting films exhibit well-controlled structure, composition, and thickness and therefore are ideal for quantifying polymer adsorption. After deposition, the sensors can be annealed without damaging the quartz crystal, resulting in a phase transition of the MoS2 from the as-deposited, amorphous phase to the 2H semiconducting phase. Furthermore, we demonstrate the application of these sensors to study the interactions of additives at the solid/liquid interface by investigating the adsorption of a model polymer, dextran, onto both the amorphous and crystalline MoS2 surfaces. We find that the adsorption rate of dextran onto the amorphous surface is approximately twice as fast as the adsorption onto the annealed surface. These studies demonstrate the ability to gain insight into the short-term kinetics of interaction between molecules and mineral surface, behavior that is key to designing additives with superior separation efficiency.
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Affiliation(s)
- Christopher S O'Bryan
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, United States; Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, United States; Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, PA, United States
| | - Joseph Rosenfeld
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Aria Zhang
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Austin W Keller
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Denis Bendejacq
- Complex Assemblies of Soft Matter Laboratory, IRL 3254, Solvay USA Inc., Bristol, PA, United States
| | - Cherie R Kagan
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, United States; Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, United States; Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States
| | - Christopher B Murray
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, United States; Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States
| | - Daeyeon Lee
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, United States.
| | - Russell J Composto
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, United States; Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, PA, United States.
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The flotation separation of molybdenite from talc using zinc sulfate in sodium silicate system and related mechanism. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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4
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Yang B, Zeng M, Zhu H, Huang P, Li Z, Song S. Selective depression of molybdenite using a novel eco-friendly depressant in Cu-Mo sulfides flotation system. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.126683] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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5
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Flotation Separation of Chalcopyrite and Molybdenite Assisted by Microencapsulation Using Ferrous and Phosphate Ions: Part I. Selective Coating Formation. METALS 2020. [DOI: 10.3390/met10121667] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Porphyry Cu-Mo deposits, which are the most important sources of copper and molybdenum, are typically processed by flotation. In order to separate Cu and Mo minerals (mostly chalcopyrite and molybdenite), the strategy of depressing chalcopyrite while floating molybdenite has been widely adopted by using chalcopyrite depressants, such as NaHS, Na2S, and Nokes reagent. However, these depressants are potentially toxic due to their possibility to emit H2S gas. Thus, this study aims at developing a new concept for selectively depressing chalcopyrite via microencapsulation while using Fe2+ and PO43− forming Fe(III)PO4 coating. The cyclic voltammetry results indicated that Fe2+ can be oxidized to Fe3+ on the chalcopyrite surface, but not on the molybdenite surface, which arises from their different electrical properties. As a result of microencapsulation treatment using 1 mmol/L Fe2+ and 1 mmol/L PO43−, chalcopyrite was much more coated with FePO4 than molybdenite, which indicated that selective depression of chalcopyrite by the microencapsulation technique is highly achievable.
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6
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Amphiphilic cellulose and surfactant mixtures as green frothers in mineral flotation. 2. Flotation of chalcopyrite and Cu-containing tailings. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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A Review of Recent Advances in Depression Techniques for Flotation Separation of Cu–Mo Sulfides in Porphyry Copper Deposits. METALS 2020. [DOI: 10.3390/met10091269] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Porphyry copper deposits (PCDs) are some of the most important sources of copper (Cu) and molybdenum (Mo). Typically, the separation and recovery of chalcopyrite (CuFeS2) and molybdenite (MoS2), the major Cu and Mo minerals, respectively, in PCDs are achieved by two-step flotation involving (1) bulk flotation to separate Cu–Mo concentrates and tailings (e.g., pyrite, silicate, and aluminosilicate minerals) and (2) Cu–Mo flotation to separate chalcopyrite and molybdenite. In Cu–Mo flotation, chalcopyrite is depressed using Cu depressants, such as NaHS, Na2S, Nokes reagent (P2S5 + NaOH), and NaCN, meaning that it is recovered as tailings, while molybdenite is floated and recovered as froth product. Although conventionally used depressants are effective in the separation of Cu and Mo, they have the potential to emit toxic and deadly gases such as H2S and HCN when operating conditions are not properly controlled. To address these problems caused by the use of conventional depressants, many studies aimed to develop alternative methods of depressing either chalcopyrite or molybdenite. In this review, recent advances in chalcopyrite and molybdenite depressions for Cu–Mo flotation separation are reviewed, including alternative organic and inorganic depressants for Cu or Mo, as well as oxidation-treatment technologies, such as ozone (O3), plasma, hydrogen peroxide (H2O2), and electrolysis, which create hydrophilic coatings on the mineral surface.
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Ketola A, Xiang W, Hjelt T, Pajari H, Tammelin T, Rojas OJ, Ketoja JA. Bubble Attachment to Cellulose and Silica Surfaces of Varied Surface Energies: Wetting Transition and Implications in Foam Forming. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:7296-7308. [PMID: 32510965 PMCID: PMC7660937 DOI: 10.1021/acs.langmuir.0c00682] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 06/06/2020] [Indexed: 05/25/2023]
Abstract
To better understand the complex system of wet foams in the presence of cellulosic fibers, we investigate bubble-surface interactions by following the effects of surface hydrophobicity and surface tension on the contact angle of captive bubbles. Bubbles are brought into contact with model silica and cellulose surfaces immersed in solutions of a foaming surfactant (sodium dodecyl sulfate) of different concentrations. It is observed that bubble attachment is controlled by surface wetting, but a significant scatter in the behavior occurs near the transition from partial to complete wetting. For chemically homogeneous silica surfaces, this transition during bubble attachment is described by the balance between the energy changes of the immersed surface and the frictional surface tension of the moving three-phase contact line. The situation is more complex with chemically heterogeneous, hydrophobic trimethylsilyl cellulose (TMSC). TMSC regeneration, which yields hydrophilic cellulose, causes a dramatic drop in the bubble contact angle. Moreover, a high interfacial tension is required to overcome the friction caused by microscopic (hydrophilic) pinning sites of the three-phase contact line during bubble attachment. A simple theoretical framework is introduced to explain our experimental observations.
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Affiliation(s)
- Annika
E. Ketola
- VTT
Technical Research Centre of Finland Ltd., P. O. Box 1603, FI-02150 Espoo, Finland
| | - Wenchao Xiang
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, FI-00076 Espoo, Finland
| | - Tuomo Hjelt
- VTT
Technical Research Centre of Finland Ltd., P. O. Box 1603, FI-02150 Espoo, Finland
| | - Heikki Pajari
- VTT
Technical Research Centre of Finland Ltd., P. O. Box 1603, FI-02150 Espoo, Finland
| | - Tekla Tammelin
- VTT
Technical Research Centre of Finland Ltd., P. O. Box 1603, FI-02150 Espoo, Finland
| | - Orlando J. Rojas
- Department
of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, FI-00076 Espoo, Finland
- Departments
of Chemical & Biological Engineering, Chemistry, and Wood Science, The University of British Columbia, 2360 East Mall, 2036 Main Mall,
and 2424 Main Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jukka A. Ketoja
- VTT
Technical Research Centre of Finland Ltd., P. O. Box 1603, FI-02150 Espoo, Finland
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9
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Wang J, Xie L, Lu Q, Wang X, Wang J, Zeng H. Electrochemical investigation of the interactions of organic and inorganic depressants on basal and edge planes of molybdenite. J Colloid Interface Sci 2020; 570:350-361. [DOI: 10.1016/j.jcis.2020.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/23/2020] [Accepted: 03/03/2020] [Indexed: 02/07/2023]
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10
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Tang X, Chen Y, Liu K, Peng Q, Zeng G, Ao M, Li Z. Reverse flotation separation of talc from molybdenite without addition of depressant: Effect of surface oxidation by thermal pre-treatment. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.124671] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Recent advances in studies of bubble-solid interactions and wetting film stability. Curr Opin Colloid Interface Sci 2019. [DOI: 10.1016/j.cocis.2019.09.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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12
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Atluri V, Jin J, Shrimali K, Dang L, Wang X, Miller JD. The hydrophobic surface state of talc as influenced by aluminum substitution in the tetrahedral layer. J Colloid Interface Sci 2019; 536:737-748. [PMID: 30415178 DOI: 10.1016/j.jcis.2018.10.085] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/24/2018] [Accepted: 10/26/2018] [Indexed: 10/28/2022]
Abstract
Talc is both an important industrial mineral product recovered by flotation, and also in other cases, a gangue mineral of concern in the flotation of certain sulfide ores, such as the PGM ores from South Africa and from the United States. The talc face surface is naturally hydrophobic with a water sessile drop contact angle of nearly 80°, which accounts for its flotation recovery in one case, and its contamination of sulfide mineral concentrates in other instances. Due to the presence of impurities in the talc structure the surface properties change. One such effect is the presence of aluminum, which can replace silicon in the silica tetrahedral layer of the talc structure. This results in a charge imbalance on the face surface because Si+4 is replaced by Al+3. Sessile drop contact angle and bubble attachment time measurements were made, and these results were compared to the results from molecular dynamics simulations (MDS). The extent of aluminum substitution in the silica tetrahedral layer was considered, and the sessile drop contact angle was found to decrease with increased aluminum content, decreasing from about 80° for no substitution (talc) to 0° for extensive substitution (phlogopite). The water film was found to be stable at the surface of highly aluminum substituted crystals due to the interaction between water molecules and the increased polarity of the surface state. This stable water film restricts the air bubble from attaching to such face surfaces. However, in the absence of aluminum substitution, no interactions between the water molecules and the face surface were observed and the air bubble readily attached to the face surface. This study provides additional understanding of how aluminum substitution in the tetrahedral layer affects the fundamental surface properties of talc, paving the way for the design of improved reagents for talc flotation as an industrial mineral product, and for talc depression in the recovery of sulfide mineral concentrates.
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Affiliation(s)
- Venkata Atluri
- Department of Metallurgical Engineering, College of Mines and Earth Sciences, University of Utah, 135 S 1460 E, Room 412, Salt Lake City, UT 84112-0114, USA
| | - Jiaqi Jin
- Department of Metallurgical Engineering, College of Mines and Earth Sciences, University of Utah, 135 S 1460 E, Room 412, Salt Lake City, UT 84112-0114, USA
| | - Kaustubh Shrimali
- Department of Metallurgical Engineering, College of Mines and Earth Sciences, University of Utah, 135 S 1460 E, Room 412, Salt Lake City, UT 84112-0114, USA
| | - Liem Dang
- Physical Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA 99352, USA.
| | - Xuming Wang
- Department of Metallurgical Engineering, College of Mines and Earth Sciences, University of Utah, 135 S 1460 E, Room 412, Salt Lake City, UT 84112-0114, USA.
| | - Jan D Miller
- Department of Metallurgical Engineering, College of Mines and Earth Sciences, University of Utah, 135 S 1460 E, Room 412, Salt Lake City, UT 84112-0114, USA.
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14
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Xie L, Wang J, Huang J, Cui X, Wang X, Liu Q, Zhang H, Liu Q, Zeng H. Anisotropic Polymer Adsorption on Molybdenite Basal and Edge Surfaces and Interaction Mechanism With Air Bubbles. Front Chem 2018; 6:361. [PMID: 30211150 PMCID: PMC6124653 DOI: 10.3389/fchem.2018.00361] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 07/30/2018] [Indexed: 11/13/2022] Open
Abstract
The anisotropic surface characteristics and interaction mechanisms of molybdenite (MoS2) basal and edge planes have attracted much research interest in many interfacial processes such as froth flotation. In this work, the adsorption of a polymer depressant [i.e., carboxymethyl cellulose (CMC)] on both MoS2 basal and edge surfaces as well as their interaction mechanisms with air bubbles have been characterized by atomic force microscope (AFM) imaging and quantitative force measurements. AFM imaging showed that the polymer coverage on the basal plane increased with elevating polymer concentration, with the formation of a compact polymer layer at 100 ppm CMC; however, the polymer adsorption was much weaker on the edge plane. The anisotropy in polymer adsorption on MoS2 basal and edge surfaces coincided with water contact angle results. Direct force measurements using CMC functionalized AFM tips revealed that the adhesion on the basal plane was about an order of magnitude higher than that on the edge plane, supporting the anisotropic CMC adsorption behaviors. Such adhesion difference could be attributed to their difference in surface hydrophobicity and surface charge, with weakened hydrophobic attraction and strengthened electrostatic repulsion between the polymers and edge plane. Force measurements using a bubble probe AFM showed that air bubble could attach to the basal plane during approach, which could be effectively inhibited after polymer adsorption. The edge surface, due to the negligible polymer adsorption, showed similar interaction behaviors with air bubbles before and after polymer treatment. This work provides useful information on the adsorption of polymers on MoS2 basal/edge surfaces as well as their interaction mechanism with air bubbles at the nanoscale, with implications for the design and development of effective polymer additives to mediate the bubble attachment on solid particles with anisotropic surface properties in mineral flotation and other engineering processes.
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Affiliation(s)
- Lei Xie
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | - Jingyi Wang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | - Jun Huang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | - Xin Cui
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | - Xiaogang Wang
- College of Material Science and Engineering, Heavy Machinery Engineering Research Center of Education Ministry, Taiyuan University of Science and Technology, Taiyuan, China
| | - Qingxia Liu
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | - Hao Zhang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | - Qi Liu
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
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Yin Z, Hu Y, Sun W, Zhang C, He J, Xu Z, Zou J, Guan C, Zhang C, Guan Q, Lin S, Khoso SA. Adsorption Mechanism of 4-Amino-5-mercapto-1,2,4-triazole as Flotation Reagent on Chalcopyrite. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:4071-4083. [PMID: 29489383 DOI: 10.1021/acs.langmuir.7b03975] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A novel compound 4-amino-5-mercapto-1,2,4-triazole was first synthesized, and its selective adsorption mechanism on the surface of chalcopyrite was comprehensively investigated using UV-vis spectra, zeta-potential, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy measurements (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and first principles calculations. The experimental and computational results consistently demonstrated that AMT would chemisorb onto the chalcopyrite surface by the formation of a five-membered chelate ring. The first principles periodic calculations further indicated that AMT would prefer to adsorb onto Cu rather than Fe due to the more negative adsorption energy of AMT on Cu in the chalcopyrite (001) surface, which was further confirmed by the coordination reaction energies of AMT-Cu and AMT-Fe based on the simplified cluster models at a higher accuracy level (UB3LYP/Def2-TZVP). The bench-scale results indicated that the selective index improved significantly when using AMT as a chalcopyrite depressant in Cu-Mo flotation separation.
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Affiliation(s)
- Zhigang Yin
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
| | - Yuehua Hu
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
| | - Wei Sun
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
| | - Chenyang Zhang
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
| | - Jianyong He
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
| | - Zhijie Xu
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
| | - Jingxiang Zou
- School of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry , Nanjing University , Nanjing 210023 , People's Republic of China
| | - Changping Guan
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
| | - Chenhu Zhang
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
| | - Qingjun Guan
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
| | - Shangyong Lin
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
| | - Sultan Ahmed Khoso
- School of Minerals Processing and Bioengineering , Central South University , Changsha , Hunan 410083 , People's Republic of China
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16
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Niu X, Ruan R, Xia L, Li L, Sun H, Jia Y, Tan Q. Correlation of Surface Adsorption and Oxidation with a Floatability Difference of Galena and Pyrite in High-Alkaline Lime Systems. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:2716-2724. [PMID: 29377706 DOI: 10.1021/acs.langmuir.7b04189] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
When it comes to Pb-Zn ores with high amounts of pyrite, the major problem encountered is the low separation efficiency between galena and pyrite. By virtue of high dosage of lime and collector sodium diethyl dithiocarbamate (DDTC), pyrite and zinc minerals are depressed, allowing the galena to be floated. However, there have been significant conflicting reports on the flotation behavior of galena at high pH. In this context, correlation of the surface adsorption and oxidation with the floatability difference of galena and pyrite in high-alkaline lime systems would be a key issue for process optimization. Captive bubble contact angle measurements were performed on freshly polished mineral surfaces in situ exposed to lime solutions of varying pH as a function of immersion time. Furthermore, single mineral microflotation tests were conducted. Both tests indicated that the degree of hydrophobicity on the surfaces of galena and pyrite increased in the presence of DDTC at natural or mild pulp pH. While in a saturated lime solution, at pH 12.5, DDTC only worked for galena, but not for pyrite. Surface chemistry analysis by time-of-flight secondary ion mass spectrometry (Tof-SIMS) confirmed the preference of DDTC on the galena surface at pH 12.5, which contributed to a merit recovery. Further important evidence through measurements of Tof-SIMS, ion chromatography, and high-performance liquid chromatography indicated that in high-alkaline lime systems, the merit floatability of galena could exclude the insignificant contribution of elemental sulfur (S8) and was dominantly attributed by the strong adsorption of DDTC. In contrast, the poor flotation response of pyrite at high pH was due to the prevailing adsorption of CaOH+ species. This study provides an important surface chemistry evidence for a better understanding of the mechanism on the better selectivity in the galena-pyrite separation adopting high-alkaline lime systems.
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Affiliation(s)
- Xiaopeng Niu
- CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences , Beijing 100190, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Renman Ruan
- CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences , Beijing 100190, China
| | - Liuyin Xia
- Surface Science Western, Research Park, University of Western Ontario , London, Ontario N6G0J3, Canada
| | - Li Li
- CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences , Beijing 100190, China
| | - Heyun Sun
- CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences , Beijing 100190, China
| | - Yan Jia
- CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences , Beijing 100190, China
| | - Qiaoyi Tan
- CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences , Beijing 100190, China
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17
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Role of Collectors and Depressants in Mineral Flotation: A Theoretical Analysis Based on Extended DLVO Theory. MINERALS 2017. [DOI: 10.3390/min7110223] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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18
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Kinetics of the bubble attachment and quartz flotation in mixed solutions of cationic and non-ionic surface-active substances. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2017.03.063] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Xie L, Shi C, Cui X, Zeng H. Surface Forces and Interaction Mechanisms of Emulsion Drops and Gas Bubbles in Complex Fluids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:3911-3925. [PMID: 28178417 DOI: 10.1021/acs.langmuir.6b04669] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The interactions of emulsion drops and gas bubbles in complex fluids play important roles in a wide range of biological and technological applications, such as programmable drug and gene delivery, emulsion and foam formation, and froth flotation of mineral particles. In this feature article, we have reviewed our recent progress on the quantification of surface forces and interaction mechanisms of gas bubbles and emulsion drops in different material systems by using several complementary techniques, including the drop/bubble probe atomic force microscope (AFM), surface forces apparatus (SFA), and four-roll mill fluidic device. These material systems include the bubble-self-assembled monolayer (SAM), bubble-polymer, bubble-superhydrophobic surface, bubble-mineral, water-in-oil and oil-in-water emulsions with interface-active components in oil production, and oil/water wetting on polyelectrolyte surfaces. The bubble probe AFM combined with reflection interference contrast microscopy (RICM) was applied for the first time to simultaneously quantify the interaction forces and spatiotemporal evolution of a confined thin liquid film between gas bubbles and solid surfaces with varying hydrophobicity. The nanomechanical results have provided useful insights into the fundamental interaction mechanisms (e.g., hydrophobic interaction in aqueous media) at gas/water/solid interfaces, the stabilization/destabilization mechanisms of emulsion drops, and oil/water wetting mechanisms on solid surfaces. A long-range hydrophilic attraction was found between water and polyelectrolyte surfaces in oil, with the strongest attraction for polyzwitterions, contributing to their superior water wettability in oil and self-cleaning capability of oil contamination. Some remaining challenges and future research directions are discussed and provided.
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Affiliation(s)
- Lei Xie
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Chen Shi
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Xin Cui
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
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Xie L, Wang J, Yuan D, Shi C, Cui X, Zhang H, Liu Q, Liu Q, Zeng H. Interaction Mechanisms between Air Bubble and Molybdenite Surface: Impact of Solution Salinity and Polymer Adsorption. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:2353-2361. [PMID: 28191980 DOI: 10.1021/acs.langmuir.6b04611] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The surface characteristics of molybdenite (MoS2) such as wettability and surface interactions have attracted much research interest in a wide range of engineering applications, such as froth flotation. In this work, a bubble probe atomic force microscope (AFM) technique was employed to directly measure the interaction forces between an air bubble and molybdenite mineral surface before/after polymer (i.e., guar gum) adsorption treatment. The AFM imaging showed that the polymer coverage on the surface of molybdenite could achieve ∼5.6, ∼44.5, and ∼100% after conditioning in 1, 5, and 10 ppm polymer solution, respectively, which coincided with the polymer coverage results based on contact angle measurements. The electrolyte concentration and surface treatment by polymer adsorption were found to significantly affect bubble-mineral interaction and attachment. The experimental force results on bubble-molybdenite (without polymer treatment) agreed well with the calculations using a theoretical model based on the Reynolds lubrication theory and augmented Young-Laplace equation including the effect of disjoining pressure. The overall surface repulsion was enhanced when the NaCl concentration decreased from 100 to 1 mM, which inhibited the bubble-molybdenite attachment. After conditioning the molybdenite surface in 1 ppm polymer solution, it was more difficult for air bubbles to attach to the molybdenite surface due to the weakened hydrophobic interaction with a shorter decay length. Increasing the polymer concentration to 5 ppm effectively inhibited bubble attachment on mineral surface, which was mainly due to the much reduced hydrophobic interaction as well as the additional steric repulsion between the extended polymer chains and bubble surface. The results provide quantitative information on the interaction mechanism between air bubbles and molybdenite mineral surfaces on the nanoscale, with useful implications for the development of effective polymer depressants and fundamental understanding of bubble-solid interactions in mineral flotation. The methodologies used in this work can be readily extended to studying similar interfacial interactions in many other engineering applications such as froth flotation deinking and bitumen extraction in oil sands industry.
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Affiliation(s)
- Lei Xie
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Jingyi Wang
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Duowei Yuan
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Chen Shi
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Xin Cui
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Hao Zhang
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Qi Liu
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Qingxia Liu
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 1H9, Canada
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Some physicochemical aspects of water-soluble mineral flotation. Adv Colloid Interface Sci 2016; 235:190-200. [PMID: 27346329 DOI: 10.1016/j.cis.2016.06.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 05/19/2016] [Accepted: 06/06/2016] [Indexed: 11/22/2022]
Abstract
Some physicochemical aspects of water-soluble mineral flotation including hydration phenomena, associations and interactions between collectors, air bubbles, and water-soluble mineral particles are presented. Flotation carried out in saturated salt solutions, and a wide range of collector concentrations for effective flotation of different salts are two basic aspects of water-soluble mineral flotation. Hydration of salt ions, mineral particle surfaces, collector molecules or ions, and collector aggregates play an important role in water-soluble mineral flotation. The adsorption of collectors onto bubble surfaces is suggested to be the precondition for the association of mineral particles with bubbles. The association of collectors with water-soluble minerals is a complicated process, which may include the adsorption of collector molecules or ions onto such surfaces, and/or the attachment of collector precipitates or crystals onto the mineral surfaces. The interactions between the collectors and the minerals include electrostatic and hydrophobic interactions, hydrogen bonding, and specific interactions, with electrostatic and hydrophobic interactions being the common mechanisms. For the association of ionic collectors with minerals with an opposite charge, electrostatic and hydrophobic interactions could have a synergistic effect, with the hydrophobic interactions between the hydrophobic groups of the previously associated collectors and the hydrophobic groups of oncoming collectors being an important attractive force. Association between solid particles and air bubbles is the key to froth flotation, which is affected by hydrophobicity of the mineral particle surfaces, surface charges of mineral particles and bubbles, mineral particle size and shape, temperature, bubble size, etc. The use of a collector together with a frother and the use of mixed surfactants as collectors are suggested to improve flotation.
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Suyantara GPW, Hirajima T, Elmahdy AM, Miki H, Sasaki K. Effect of kerosene emulsion in MgCl2 solution on the kinetics of bubble interactions with molybdenite and chalcopyrite. Colloids Surf A Physicochem Eng Asp 2016. [DOI: 10.1016/j.colsurfa.2016.04.039] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Wu J, Delcheva I, Ngothai Y, Krasowska M, Beattie DA. Bubble-surface interactions with graphite in the presence of adsorbed carboxymethylcellulose. SOFT MATTER 2015; 11:587-99. [PMID: 25515526 DOI: 10.1039/c4sm02380c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The adsorption of carboxymethylcellulose (CMC), and the subsequent effect on bubble-surface interactions, has been studied for a graphite surface. CMC adsorbs on highly oriented pyrolytic graphite (HOPG) in specific patterns: when adsorbed from a solution of low concentration it forms stretched, isolated and sparsely distributed chains, while upon adsorption from a solution of higher concentration, it forms an interconnected network of multilayer features. The amount and topography of the adsorbed CMC affect the electrical properties as well as the wettability of the polymer-modified HOPG surface. Adsorption of CMC onto the HOPG surface causes the zeta potential to be more negative and the modified surface becomes more hydrophilic. This increase in both the absolute value of zeta potential and the surface hydrophilicity originates from the carboxymethyl groups of the CMC polymer. The effect of the adsorbed polymer layer on wetting film drainage and bubble-surface/particle attachment was determined using high speed video microscopy to monitor single bubble-surface collision, and single bubble Hallimond tube flotation experiments. The time of wetting film drainage and the time of three-phase contact line spreading gets significantly longer for polymer-modified HOPG surfaces, indicating that the film rupture and three-phase contact line expansion were inhibited by the presence of polymer. The effect of longer drainage times and slower dewetting correlated with reduced flotation recovery. The molecular kinetic (MK) model was used to quantify the effect of the polymer on dewetting dynamics, and showed an increase in the jump frequency for the polymer adsorbed at the higher concentration.
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Affiliation(s)
- Jueying Wu
- Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.
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