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Liu P, Nie S, Wang W, Zhang S, Bate B, Chen Y. CFD-DEM study on transport and retention behaviors of nZVI-clay colloids in porous media. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133048. [PMID: 38006862 DOI: 10.1016/j.jhazmat.2023.133048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 11/04/2023] [Accepted: 11/19/2023] [Indexed: 11/27/2023]
Abstract
Transportation process of nano scale zero valent iron (nZVI) in clay-rich soils is complicated and crucial for in-situ remediation of contaminated sites. A coupled computational fluid dynamic and discrete element method (CFD-DEM) was used to investigate the interplays of repulsive and attractive forces and the injection velocity of this process. The screened Coulomb's law was used to represent the electrostatic interaction, and surface energy density was introduced to represent the effects of the van der Waals interaction. A phase diagram was constructed to describe the interplay between injection velocity and repulsive force (in terms of charge of colloids). Under the boundary and initial conditions in this study, clogging formed at low repulsive force (colloidal charge = -1 ×10-15 C), where increment of injection velocity (from 0.002 m/s to 0.02 m/s) cannot prevent clogging, as in the case of bare nZVI transportation with limited mobility; On the other hand, excessive repulsive force (charge = -4 ×10-14 C) is detrimental to nZVI-clay transportation due to repulsion from the concentrated colloids in pore throats, a phenomenon as in the overuse of stabilizers and was defined as the "membrane repulsion effect" in this study. At moderate charge (-1 ×10-14 C), injection velocity increment induced clogging due to aggregates formed at the windward of cylinder and accumulated at the pore throats.
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Affiliation(s)
- Pengfei Liu
- Hypergravity Research Center, Zhejiang University, Hangzhou, China; Institute of Geotechnical Engineering, Zhejiang University, Hangzhou, China
| | - Shaokai Nie
- Institute of Geotechnical Engineering, Zhejiang University, Hangzhou, China
| | - Wenyuan Wang
- Institute of Geotechnical Engineering, Zhejiang University, Hangzhou, China
| | - Shuai Zhang
- Institute of Geotechnical Engineering, Zhejiang University, Hangzhou, China
| | - Bate Bate
- Institute of Geotechnical Engineering, Zhejiang University, Hangzhou, China.
| | - Yunmin Chen
- Hypergravity Research Center, Zhejiang University, Hangzhou, China; Institute of Geotechnical Engineering, Zhejiang University, Hangzhou, China
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2
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Yang Y, Yuan W, Hou J, You Z. Review on physical and chemical factors affecting fines migration in porous media. WATER RESEARCH 2022; 214:118172. [PMID: 35196620 DOI: 10.1016/j.watres.2022.118172] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/01/2022] [Accepted: 02/08/2022] [Indexed: 06/14/2023]
Abstract
Permeability reduction and formation damage in porous media caused by fines (defined as unconfined solid particles present in the pore spaces) migration is one of the major reasons for productivity decline. It is well accepted that particle detachment occurs under imbalanced torques arising from hydrodynamic and adhesive forces exerted on attached particles. This paper reviewed current understanding on primary factors influencing fines migration as well as mathematical formulations for quantification. We also introduced salinity-related experimental observations that contradict theoretical predictions based on torque balance criteria, such as delayed particle release and attachment-detachment hysteresis. The delay of particle release during low-salinity water injection was successfully explained and formulated by the Nernst-Planck diffusion of ions in a narrow contact area. In addition to the widely recognized explanation by surface heterogeneity and the presence of low-velocity regions, we proposed a hypothesis that accounts for the shifting of equilibrium positions, providing new insight into the interpretation of elusive attachment-detachment hysteresis both physically and mathematically. The review was finalized by discussing the quantification of anomalous salinity effect on adhesion force at low- and high-salinity conditions.
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Affiliation(s)
- Yulong Yang
- State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102200, China.
| | - Weifeng Yuan
- State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102200, China
| | - Jirui Hou
- State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102200, China
| | - Zhenjiang You
- Center for Sustainable Energy and Resources, Edith Cowan University, Joondalup, WA 6027, Australia; School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia; Centre for Natural Gas, The University of Queensland, Brisbane, QLD 4072, Australia.
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3
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Bonto M, Eftekhari AA, Nick HM. Electrokinetic behavior of artificial and natural calcites: A review of experimental measurements and surface complexation models. Adv Colloid Interface Sci 2022; 301:102600. [PMID: 35065336 DOI: 10.1016/j.cis.2022.102600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 01/06/2022] [Accepted: 01/09/2022] [Indexed: 11/28/2022]
Abstract
The surface charge of calcite in aqueous environments is essential to many industrial and environmental applications. Electrokinetic measurements are usually used to assess the calcite charging behavior and characterize its electrical double layer (EDL). Numerous surface complexation models (SCMs) have been proposed to interpret the effect of different surface interactions on the zeta potential. Because of their versatility, SCMs have also become important tools in reactive transport modeling. The research on enhanced oil recovery within the last decade has led to an increased number of publications reporting both zeta potential measurements and SCMs for calcite. Nonetheless, the measurements are often inconsistent and the reasons for choosing one model over another are unclear. In this work, we review the models proposed for calcite and address their main differences. We first collect a large number of published zeta potential measurements and then we fit a Diffuse Layer, Basic Stern, and Charge-Distribution Multi-Site Complexation models to a selected reliable dataset. For each model, we maintain a similar number of adjustable parameters. After optimizing the parameters of the models, we systematically compare their prediction capabilities against data obtained in monovalent and divalent electrolyte systems containing calcium, magnesium, sulfate, or carbonate. We show that, often, the discrepancies between the models and the experimental data can be explained by different levels of disequilibrium. Nonetheless, assumptions used in the development of the models may significantly reduce their extrapolability to variable chemical conditions. The poor agreement between the models tuned to electrokinetic data with surface charge measurements and dynamic retention from single-phase flowthrough tests show that zeta potential may not be the best type of data to characterize ion binding at the calcite surface. Including the effect of mineral impurities and temperature on the calcite surface speciation and electrokinetic behavior prevail as main challenges for reactive transport modeling.
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Affiliation(s)
- María Bonto
- Danish Hydrocarbon Research and Technology Centre, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark.
| | - Ali A Eftekhari
- Danish Hydrocarbon Research and Technology Centre, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
| | - Hamidreza M Nick
- Danish Hydrocarbon Research and Technology Centre, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
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Wu H, Renno AD, Foucaud Y, Rudolph M. Study of the Influence of the Crystallographic Orientation of Cassiterite Observed with Colloidal Probe Atomic Force Microscopy and its Implications for Hydrophobization by an Anionic Flotation Collector. ACS OMEGA 2021; 6:4212-4226. [PMID: 33644544 PMCID: PMC7908031 DOI: 10.1021/acsomega.0c03980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
In this study, the physicochemical behaviors of the (110), (100), as well as (001) of SnO2 were investigated by using high-resolution direct force spectroscopy. The measurements were conducted between a silica sphere and sample surfaces in 10 mmol/L KCl between pH 3.1 and 6.2 using colloidal probe atomic force microscopy (cp-AFM-hydrophilic). Dissimilar interactions were detected on different-oriented surfaces. The pH values where the force switched from positive to negative can be clearly distinguished and be ordered as SnO2(100) < SnO2(001) ≈ SnO2(110). By fitting the force curves in the Derjaguin-Landau-Verwey-Overbeck theory framework, anisotropic surface potentials were computed between the three sample surfaces following a similar trend as force interaction. To study the implication of crystallographic orientation to surfactant adsorption, we used Aerosol 22 (sulfosuccinamate) as an anionic collector for cassiterite flotation to functionalize the different samples at pH 3. The contact angle measurements, the topography visualizations by AFM, and the force measurement using cp-AFM with hydrophobized spheres (cp-AFM-hydrophobized) have shown that Aerosol 22 was adsorbed on the sample surfaces inhomogeneously. The adsorption followed the range of SnO2(110) > SnO2(100) > SnO2(001) in the concentration from 1 × 10-6 to 1 × 10-4 mol/L.
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Affiliation(s)
- Haosheng Wu
- Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), Helmholtz Institute Freiberg for Resource
Technology (HIF), Chemnitzer
Str. 40, Freiberg 09599, Germany
| | - Axel D. Renno
- Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), Helmholtz Institute Freiberg for Resource
Technology (HIF), Chemnitzer
Str. 40, Freiberg 09599, Germany
| | - Yann Foucaud
- ICSM,
Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, Bagnols-sur-Cèze 30207, France
| | - Martin Rudolph
- Helmholtz-Zentrum
Dresden-Rossendorf (HZDR), Helmholtz Institute Freiberg for Resource
Technology (HIF), Chemnitzer
Str. 40, Freiberg 09599, Germany
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Li D, Wang H, Li C, Liang Y, Yan X, Zhang H. Determination and modulation of the typical interactions among dispersed phases relevant to flotation applications: A review. Adv Colloid Interface Sci 2021; 288:102359. [PMID: 33422930 DOI: 10.1016/j.cis.2020.102359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/04/2020] [Accepted: 12/24/2020] [Indexed: 11/28/2022]
Abstract
Flotation is a process involving multi-components, multi-scales, and gas-liquid-solid three phases, where the material separation is achieved based on the difference in surface hydrophobicity of various constituents. In a flotation system, fluids are usually regarded as the continuous phase, while the dispersed phases refer to scattered particles, bubbles, and droplets with low solubility as a dispersion that is surrounded by the aqueous environment. Fundamentally, the interactions among dispersed phases exist throughout the flotation process, and play distinct roles during different periods. For example, the liquid collector-solid, solid-solid, bubble-bubble and gas bubble-solid interactions are closely associated with the particle surface modification, particle behavior, bubble size evolution and separation in flotation, respectively. Therefore, the influences of each stage are all worthy of concern, and should be spared sufficient attention, which requires to formulate a horizontal writing structure. In this review, instead of summarizing all available characterization techniques or measurements, certain typical examples or methods were consciously chosen to perform analysis or comparison, aiming to summarize recent studies on the determination and modulation of dispersed phase interactions. The determination on the interactions among dispersed phases is helpful for fundamentally understanding the microcosmic process connotations, and their modulation contributes to firmly providing macroscopic optimization schemes for practical applications. By integrating some typically available theoretical calculations and experimental measurements related to the dispersed phase interactions, the present article is devoted to revealing the influential factors, finding out the current challenges or knowledge gaps, and affording certain references or suggestions for future investigations.
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Affiliation(s)
- Danlong Li
- National Engineering Research Center for Coal Preparation and Purification, China University of Mining and Technology, 221116 Xuzhou, China; School of Chemical Engineering and Technology, China University of Mining and Technology, 221116 Xuzhou, China
| | - Hainan Wang
- National Engineering Research Center for Coal Preparation and Purification, China University of Mining and Technology, 221116 Xuzhou, China; School of Chemical Engineering and Technology, China University of Mining and Technology, 221116 Xuzhou, China
| | - Chenwei Li
- National Engineering Research Center for Coal Preparation and Purification, China University of Mining and Technology, 221116 Xuzhou, China; School of Chemical Engineering and Technology, China University of Mining and Technology, 221116 Xuzhou, China
| | - Yannan Liang
- National Engineering Research Center for Coal Preparation and Purification, China University of Mining and Technology, 221116 Xuzhou, China; School of Chemical Engineering and Technology, China University of Mining and Technology, 221116 Xuzhou, China
| | - Xiaokang Yan
- National Engineering Research Center for Coal Preparation and Purification, China University of Mining and Technology, 221116 Xuzhou, China; School of Chemical Engineering and Technology, China University of Mining and Technology, 221116 Xuzhou, China
| | - Haijun Zhang
- National Engineering Research Center for Coal Preparation and Purification, China University of Mining and Technology, 221116 Xuzhou, China; School of Chemical Engineering and Technology, China University of Mining and Technology, 221116 Xuzhou, China.
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6
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Huang S, Rahmani AM, Singletary T, Colosqui CE. Molecular dynamics and continuum analyses of the electrokinetic zeta potential in nanostructured slit channels. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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7
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Li K, Ma H. Rotation and Retention Dynamics of Rod-Shaped Colloids with Surface Charge Heterogeneity in Sphere-in-Cell Porous Media Model. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:5471-5483. [PMID: 30925063 DOI: 10.1021/acs.langmuir.9b00748] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Colloid surface charge heterogeneity was incorporated into a three-dimensional trajectory model, which simulated particle translation and rotation via a force/torque analysis, to study the transport and retention dynamics of rod-shaped colloids over a wide size range in porous media under unfavorable conditions (energy barriers to deposition exist). Our previous study Li , K. ; Ma , H. Deposition Dynamics of Rod-Shaped Colloids during Transport in Porous Media under Favorable Conditions , Langmuir , 2018 , 34 , 9 , 2967 - 2980 , 10.1021/acs.langmuir.7b03983 for rod transport under favorable conditions (lacking energy barriers) demonstrated that particle rotation due to the coupled effect of flow hydrodynamics and Brownian rotation governed rod transport and retention. In this work, we showed that the shape of a colloid affected both transport process and colloid-collector interactions, but shape alone could not make rods to overcome energy barriers of over tens of kT for attachment under unfavorable conditions. The location of colloid surface heterogeneity did not affect transport but predominantly affected colloid-surface interactions by influencing the likelihood of heterogeneity patches facing the collector due to particle rotation. For surface heterogeneity located on the end(s) of a colloid, rods displayed enhanced retention compared with spheres; for surface heterogeneity located on the middle band, rods showed less retention compared with spheres. It was more effective to arrest a traveling rod when surface heterogeneity was located on the end relative to the side, because the tumbling motion greatly increased the likelihood of the end to intercept collector surfaces, and also because a rod would experience less repulsion with an end-on orientation relative to the collector surface compared to a side-on orientation due to the curvature effect. The influences of the particle aspect ratio on retention strongly depended upon the location of colloid surface heterogeneity. Our findings demonstrated that rods had distinct rotation and retention behaviors from spheres under conditions typically encountered in the environment; thus, particle rotation should be considered when studying the transport process of nonspherical colloids or spherical particles with inhomogeneous surface properties.
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Affiliation(s)
- Ke Li
- Department of Geology and Geophysics , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Huilian Ma
- Department of Geology and Geophysics , University of Utah , Salt Lake City , Utah 84112 , United States
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8
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Rasmuson A, VanNess K, Ron CA, Johnson WP. Hydrodynamic versus Surface Interaction Impacts of Roughness in Closing the Gap between Favorable and Unfavorable Colloid Transport Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2450-2459. [PMID: 30762346 DOI: 10.1021/acs.est.8b06162] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Recent experiments revealed that roughness decreases the gap in colloid attachment between favorable (repulsion absent) and unfavorable (repulsion present) conditions through a combination of hydrodynamic slip and surface interactions with asperities. Hydrodynamic slip was calibrated to experimentally observed tangential colloid velocities, demonstrating that slip length was equal to maximum asperity relief, thereby providing a functional relationship between slip and roughness metrics. Incorporation of the slip length in mechanistic particle trajectory simulations yielded the observed modest decrease in attachment over rough surfaces under favorable conditions, with the observed decreased attachment being due to reduced colloid delivery rather than decreased attraction. Cumulative interactions with multiple asperities acting within the zone of colloid-surface interaction were unable to produce the observed dramatic increased attachment and decreased reversibility with increased roughness under unfavorable conditions, necessitating inclusion of nanoscale attractive heterogeneity that was inferred to have codeveloped with roughness. Simulated attachment matched experimental observations when the spatial frequency of larger heterodomains (nanoscale zones of attraction) increased disproportionately relative to smaller heterodomains as roughness increased, whereas attachment was insensitive to asperity properties, including the number of interactions per asperity and asperity height; colloid detachment simulations were highly sensitive to these parameters. These cumulative findings reveal that hydrodynamic slip moderately decreases colloid bulk delivery, nanoscale heterogeneity dramatically enhances colloid attachment, and multiple interactions among asperities decrease detachment from rough surfaces.
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Affiliation(s)
- Anna Rasmuson
- Department of Geology and Geophysics , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Kurt VanNess
- Department of Geology and Geophysics , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Cesar A Ron
- Department of Geology and Geophysics , University of Utah , Salt Lake City , Utah 84112 , United States
| | - William P Johnson
- Department of Geology and Geophysics , University of Utah , Salt Lake City , Utah 84112 , United States
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10
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Collins L, Kilpatrick JI, Kalinin SV, Rodriguez BJ. Towards nanoscale electrical measurements in liquid by advanced KPFM techniques: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:086101. [PMID: 29990308 DOI: 10.1088/1361-6633/aab560] [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
Fundamental mechanisms of energy storage, corrosion, sensing, and multiple biological functionalities are directly coupled to electrical processes and ionic dynamics at solid-liquid interfaces. In many cases, these processes are spatially inhomogeneous taking place at grain boundaries, step edges, point defects, ion channels, etc and possess complex time and voltage dependent dynamics. This necessitates time-resolved and real-space probing of these phenomena. In this review, we discuss the applications of force-sensitive voltage modulated scanning probe microscopy (SPM) for probing electrical phenomena at solid-liquid interfaces. We first describe the working principles behind electrostatic and Kelvin probe force microscopies (EFM & KPFM) at the gas-solid interface, review the state of the art in advanced KPFM methods and developments to (i) overcome limitations of classical KPFM, (ii) expand the information accessible from KPFM, and (iii) extend KPFM operation to liquid environments. We briefly discuss the theoretical framework of electrical double layer (EDL) forces and dynamics, the implications and breakdown of classical EDL models for highly charged interfaces or under high ion concentrations, and describe recent modifications of the classical EDL theory relevant for understanding nanoscale electrical measurements at the solid-liquid interface. We further review the latest achievements in mapping surface charge, dielectric constants, and electrodynamic and electrochemical processes in liquids. Finally, we outline the key challenges and opportunities that exist in the field of nanoscale electrical measurements in liquid as well as providing a roadmap for the future development of liquid KPFM.
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Affiliation(s)
- Liam Collins
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America. Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
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11
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Li K, Ma H. Deposition Dynamics of Rod-Shaped Colloids during Transport in Porous Media under Favorable Conditions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:2967-2980. [PMID: 29400469 DOI: 10.1021/acs.langmuir.7b03983] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A three-dimensional computational modeling study of the deposition dynamics of rod-shaped colloids during transport in porous media under favorable conditions (no energy barrier to deposition) is presented. The objective was to explore the influences of the particle shape on colloid transport and retention. During simulation, both translation and rotation of ellipsoidal particles were tracked and evaluated based on an analysis of all forces and torques acting on the particle. We observed that the shape was a key factor affecting colloid transport and attachment. Rod particles exhibited enhanced retention compared with spheres of equivalent volume in the size range greater than ∼200 nm. The shape effect was the most pronounced for particles around 200 nm to 1 μm under simulated conditions. The shape effect was also strongly dependent upon the fluid velocity; it was most significant at high velocity, but not so at very low velocity. The above-described shape effect on retention was directly related to particle rotation dynamics due to the coupled effects from rotational diffusion and flow hydrodynamics. Rotational diffusion changed the particle orientation randomly, which caused the rod particles to drift considerably across flow streamlines for attachment in the size range from 200 nm to 1 μm. The hydrodynamic effect induced periodic particle rotation and oscillation, which rendered large-sized rod particles to behave like "spinning bodies," prescribed by their long axes so as to easily intercept with the collector surface for retention. Our findings demonstrated that the practice of using equivalent spheres to approximate rods is inadequate in predicting the transport fate and adhesion dynamics of rod-shaped colloids in porous media.
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Affiliation(s)
- Ke Li
- Department of Geology and Geophysics , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Huilian Ma
- Department of Geology and Geophysics , University of Utah , Salt Lake City , Utah 84112 , United States
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12
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Adar RM, Andelman D, Diamant H. Electrostatics of patchy surfaces. Adv Colloid Interface Sci 2017; 247:198-207. [PMID: 28526129 DOI: 10.1016/j.cis.2017.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/30/2017] [Accepted: 04/03/2017] [Indexed: 10/19/2022]
Abstract
In the study of colloidal, biological and electrochemical systems, it is customary to treat surfaces, macromolecules and electrodes as homogeneously charged. This simplified approach is proven successful in most cases, but fails to describe a wide range of heterogeneously charged surfaces commonly used in experiments. For example, recent experiments have revealed a long-range attraction between overall neutral surfaces, locally charged in a mosaic-like structure of positively and negatively charged domains ("patches"). Here, we review experimental and theoretical studies addressing the stability of heterogeneously charged surfaces, their effect on ionic profiles in solution, and the interaction between two such surfaces. We focus on electrostatics, and highlight the important new physical parameters appearing in the heterogeneous case, such as the largest patch size and inter-surface charge correlations.
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13
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Nakashima T, Suhara H, Murata H, Shimoyama H. Method for Estimating the Charge Density Distribution on a Dielectric Surface. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:472-483. [PMID: 28399948 DOI: 10.1017/s1431927617000423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
High-quality color output from digital photocopiers and laser printers is in strong demand, motivating attempts to achieve fine dot reproducibility and stability. The resolution of a digital photocopier depends on the charge density distribution on the organic photoconductor surface; however, directly measuring the charge density distribution is impossible. In this study, we propose a new electron optical instrument that can rapidly measure the electrostatic latent image on an organic photoconductor surface, which is a dielectric surface, as well as a novel method to quantitatively estimate the charge density distribution on a dielectric surface by combining experimental data obtained from the apparatus via a computer simulation. In the computer simulation, an improved three-dimensional boundary charge density method (BCM) is used for electric field analysis in the vicinity of the dielectric material with a charge density distribution. This method enables us to estimate the profile and quantity of the charge density distribution on a dielectric surface with a resolution of the order of microns. Furthermore, the surface potential on the dielectric surface can be immediately calculated using the obtained charge density. This method enables the relation between the charge pattern on the organic photoconductor surface and toner particle behavior to be studied; an understanding regarding the same may lead to the development of a new generation of higher resolution photocopiers.
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Affiliation(s)
- Takuya Nakashima
- 1Faculty of Science and Technology,Meijo University,Tempaku-ku,Nagoya 468-8502,Japan
| | - Hiroyuki Suhara
- 2RICOH Co., Ltd.,810,Shimo-imaizumi,Ebina-shi,Kanagawa 243-0460,Japan
| | - Hidekazu Murata
- 1Faculty of Science and Technology,Meijo University,Tempaku-ku,Nagoya 468-8502,Japan
| | - Hiroshi Shimoyama
- 1Faculty of Science and Technology,Meijo University,Tempaku-ku,Nagoya 468-8502,Japan
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14
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Ding H, Rahman S. Experimental and theoretical study of wettability alteration during low salinity water flooding-an state of the art review. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2017.02.006] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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Johnson JN, Nourhani A, Peralta R, McDonald C, Thiesing B, Mann CJ, Lammert PE, Gibbs JG. Dynamic stabilization of Janus sphere trans-dimers. Phys Rev E 2017; 95:042609. [PMID: 28505853 DOI: 10.1103/physreve.95.042609] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Indexed: 06/07/2023]
Abstract
We experimentally investigated the self-assembly of chemically active colloidal Janus spheres into dimers. The trans-dimer conformation, in which the two active sites are oriented roughly in opposite directions and the particles are osculated at their equators, becomes dominant as the hydrogen peroxide fuel concentration increases. Our observations suggest high spinning frequency combined with little translational motion is at least partially responsible for the stabilization of the trans-dimer as activity increases.
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Affiliation(s)
- Joel N Johnson
- Department of Physics and Astronomy, Northern Arizona University, Flagstaff, Arizona 86011, USA
| | - Amir Nourhani
- Department of Physics and Astronomy, Northern Arizona University, Flagstaff, Arizona 86011, USA
- Center for Nanoscale Science, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Robert Peralta
- Department of Physics and Astronomy, Northern Arizona University, Flagstaff, Arizona 86011, USA
| | - Christopher McDonald
- Department of Physics and Astronomy, Northern Arizona University, Flagstaff, Arizona 86011, USA
| | - Benjamin Thiesing
- Department of Physics and Astronomy, Northern Arizona University, Flagstaff, Arizona 86011, USA
| | - Christopher J Mann
- Department of Physics and Astronomy, Northern Arizona University, Flagstaff, Arizona 86011, USA
| | - Paul E Lammert
- Center for Nanoscale Science, Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - John G Gibbs
- Department of Physics and Astronomy, Northern Arizona University, Flagstaff, Arizona 86011, USA
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16
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Li T, Jin Y, Huang Y, Li B, Shen C. Observed Dependence of Colloid Detachment on the Concentration of Initially Attached Colloids and Collector Surface Heterogeneity in Porous Media. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2811-2820. [PMID: 28190337 DOI: 10.1021/acs.est.6b06264] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Sand column experiments were conducted to examine the effects of the concentration of attached colloids (CAC) on their subsequent detachment upon decreasing solution ionic strength (IS). Different pore volumes of latex microparticle suspensions were injected into the columns to allow different amounts of colloids to attach at ISs of 0.001, 0.01, and 0.2 M. Then, deionized water was introduced to release the attached colloids. Results show that the fraction of attachments that were reversible to reduction of IS (FRA) increased with increasing CAC at a given IS if the sand was extensively treated using acids to reduce surface charge heterogeneity. This indicates that colloids were preferentially immobilized in sites favoring irreversible attachment and then gradually occupied reversible sites. In contrast, the FRA decreased with increasing CAC at 0.001 M in sand without the acid treatment, illustrating the opposite attachment sequence. Scanning electron microscope examinations reveal that the concave regions favored irreversible colloid attachment. Reversible attachment is likely due to immobilization on flat surfaces with charge heterogeneities, retention in stagnation point regions via secondary minimum association, ripening in the acid-treated sand, and capture of colloids by protruding asperities with charge heterogeneity in the untreated sand. At ISs of 0.01 and 0.2 M, the FRA was essentially independent of CAC in the untreated sand because the colloids were randomly attached on the sand surfaces over time.
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Affiliation(s)
- Tiantian Li
- Department of Soil and Water Sciences, China Agricultural University , Beijing 100193, China
| | - Yan Jin
- Department of Plant and Soil Sciences, University of Delaware , Newark, Delaware 19716, United States
| | - Yuanfang Huang
- Department of Soil and Water Sciences, China Agricultural University , Beijing 100193, China
| | - Baoguo Li
- Department of Soil and Water Sciences, China Agricultural University , Beijing 100193, China
| | - Chongyang Shen
- Department of Soil and Water Sciences, China Agricultural University , Beijing 100193, China
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Rasmuson A, Pazmino E, Assemi S, Johnson WP. Contribution of Nano- to Microscale Roughness to Heterogeneity: Closing the Gap between Unfavorable and Favorable Colloid Attachment Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2151-2160. [PMID: 28132502 DOI: 10.1021/acs.est.6b05911] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Surface roughness has been reported to both increase as well as decrease colloid retention. In order to better understand the boundaries within which roughness operates, attachment of a range of colloid sizes to glass with three levels of roughness was examined under both favorable (energy barrier absent) and unfavorable (energy barrier present) conditions in an impinging jet system. Smooth glass was found to provide the upper and lower bounds for attachment under favorable and unfavorable conditions, respectively. Surface roughness decreased, or even eliminated, the gap between favorable and unfavorable attachment and did so by two mechanisms: (1) under favorable conditions attachment decreased via increased hydrodynamic slip length and reduced attraction and (2) under unfavorable conditions attachment increased via reduced colloid-collector repulsion (reduced radius of curvature) and increased attraction (multiple points of contact, and possibly increased surface charge heterogeneity). Absence of a gap where these forces most strongly operate for smaller (<200 nm) and larger (>2 μm) colloids was observed and discussed. These observations elucidate the role of roughness in colloid attachment under both favorable and unfavorable conditions.
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Affiliation(s)
- Anna Rasmuson
- Department of Geology and Geophysics, University of Utah , Salt Lake City, Utah 84112, United States
| | - Eddy Pazmino
- Department of Extractive Metallurgy, Escuela Politécnica Nacional , Quito, Ecuador
| | - Shoeleh Assemi
- Department of Metallurgical Engineering, University of Utah , Salt Lake City, Utah 84112, United States
| | - William P Johnson
- Department of Geology and Geophysics, University of Utah , Salt Lake City, Utah 84112, United States
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18
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Adar RM, Andelman D, Diamant H. Electrostatic attraction between overall neutral surfaces. Phys Rev E 2016; 94:022803. [PMID: 27627373 DOI: 10.1103/physreve.94.022803] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Indexed: 06/06/2023]
Abstract
Two overall neutral surfaces with positively and negatively charged domains ("patches") have been shown in recent experiments to exhibit long-range attraction when immersed in an ionic solution. Motivated by the experiments, we calculate analytically the osmotic pressure between such surfaces within the Poisson-Boltzmann framework, using a variational principle for the surface-averaged free energy. The electrostatic potential, calculated beyond the linear Debye-Hückel theory, yields an overall attraction at large intersurface separations, over a wide range of the system's controlled length scales. In particular, the attraction is stronger and occurs at smaller separations for surface patches of larger size and charge density. In this large patch limit, we find that the attraction-repulsion crossover separation is inversely proportional to the square of the patch-charge density and to the Debye screening length.
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Affiliation(s)
- Ram M Adar
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - David Andelman
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Haim Diamant
- Raymond and Beverly Sackler School of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
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19
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Gao Z, Hu Y, Sun W, Drelich JW. Surface-Charge Anisotropy of Scheelite Crystals. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:6282-8. [PMID: 27269369 DOI: 10.1021/acs.langmuir.6b01252] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Atomic force microscopy was employed to measure the colloidal interactions between silicon nitride cantilever tips and scheelite crystal surfaces in 1 mM KCl solutions of varying pH. By fitting the Derjguin-Landau-Verwey-Overbeek (DLVO) theoretical model to the recorded force-distance curves, the surface-charge density and surface-potential values were calculated for three crystallographic surfaces including {112}, {101}, and {001}. The calculated surface-potential values were negative in both acidic and basic solutions and varied among crystallographic surfaces. The determined surface-potential values were within zeta-potential values reported in the literature for powdered scheelite minerals. The surface {101} was the most negatively charged surface, followed by {112} and {001}. The surface potential for {001} was only slightly affected by pH, whereas the surface potential for both {112} and {101} increased with increasing pH. Anisotropy in surface-charge density was analyzed in relation to the surface density of active oxygen atoms, that is, the density of oxygen atoms with one or two broken bond(s) within tungstate ions located in the topmost surface layer. On a surface with a higher surface density of active oxygen atoms, a larger number of OH(-) are expected to adsorb through hydrogen bonding, leading to a more negatively charged surface.
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Affiliation(s)
- Zhiyong Gao
- School of Minerals Processing and Bioengineering, Central South University , Changsha 410083, China
| | - Yuehua Hu
- School of Minerals Processing and Bioengineering, Central South University , Changsha 410083, China
| | - Wei Sun
- School of Minerals Processing and Bioengineering, Central South University , Changsha 410083, China
| | - Jaroslaw W Drelich
- Department of Materials Science and Engineering, Michigan Technological University , Houghton, Michigan 49931, United States
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20
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Ostvar S, Wood BD. Multiscale Model Describing Bacterial Adhesion and Detachment. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:5213-5222. [PMID: 27129780 DOI: 10.1021/acs.langmuir.6b00882] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Bacterial surfaces are complex structures with nontrivial adhesive properties. The physics of bacterial adhesion deviates from that of ideal colloids as a result of cell-surface roughness and because of the mechanical properties of the polymers covering the cell surface. In the present study, we develop a simple multiscale model for the interplay between the potential energy functions that characterize the cell surface biopolymers and their interaction with the extracellular environment. We then use the model to study a discrete network of bonds in the presence of significant length heterogeneities in cell-surface polymers. The model we present is able to generate force curves (both approach and retraction) that closely resemble those measured experimentally. Our results show that even small-length-scale heterogeneities can lead to macroscopically nonlinear behavior that is qualitatively and quantitatively different from the homogeneous case. We also report on the energetic consequences of such structural heterogeneity.
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Affiliation(s)
- Sassan Ostvar
- School of Chemical, Biological, and Environmental Engineering, Oregon State University , Corvallis, Oregon 97331, United States
| | - Brian D Wood
- School of Chemical, Biological, and Environmental Engineering, Oregon State University , Corvallis, Oregon 97331, United States
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21
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Liu J, Gaikwad R, Hande A, Das S, Thundat T. Mapping and Quantifying Surface Charges on Clay Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:10469-10476. [PMID: 26352908 DOI: 10.1021/acs.langmuir.5b02859] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Understanding the electrical properties of clay nanoparticles is very important since they play a crucial role in every aspect of oil sands processing, from bitumen extraction to sedimentation in mature fine tailings (MFT). Here, we report the direct mapping and quantification of surface charges on clay nanoparticles using Kelvin probe force microscopy (KPFM) and electrostatic force microscopy (EFM). The morphology of clean kaolinite clay nanoparticles shows a layered structure, while the corresponding surface potential map shows a layer-dependent charge distribution. More importantly, a surface charge density of 25 nC/cm(2) was estimated for clean kaolinite layers by using EFM measurements. On the other hand, the EFM measurements show that the clay particles obtained from the tailings demonstrate a reduced surface charge density of 7 nC/cm(2), which may be possibly attributed to the presence of various bituminous compounds residing on the clay surfaces.
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Affiliation(s)
- Jun Liu
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2 V4, Canada
| | - Ravi Gaikwad
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2 V4, Canada
| | - Aharnish Hande
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2 V4, Canada
| | - Siddhartha Das
- Department of Mechanical Engineering, University of Maryland , College Park, Maryland 20742, United States
| | - Thomas Thundat
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2 V4, Canada
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22
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Bargozin H, Hadadhania RA, Faraji H, Yavari M. The DLVO Energy Interaction of Nanorough Surfaces by Spherical Coordinates. J DISPER SCI TECHNOL 2015. [DOI: 10.1080/01932691.2015.1070356] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Bargozin H, Hadadhania RA, Amiri TY. Influence of Chemical Heterogeneity and Nanoscale Roughness on the DLVO Energy Interaction by Spherical Coordinates. J DISPER SCI TECHNOL 2015. [DOI: 10.1080/01932691.2015.1063064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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24
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Herman D, Walz JY. Effects of metal oxide nanoparticles on the stability of dispersions of weakly charged colloids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:4844-4852. [PMID: 25860256 DOI: 10.1021/acs.langmuir.5b00745] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The stability behavior of dispersions of weakly charged silica colloids was studied in the presence of highly charged metal oxide nanoparticles. Experiments were performed using 5 nm zirconia as well as 10 nm alumina nanoparticles (both positively charged), which were added to 0.1 vol % suspensions of 1.0 μm silica microparticles at the silica IEP. Both types of nanoparticles provided effective stabilization of the silica; i.e., the silica suspensions were stabilized for longer than the observation period (greater than 12 h). Stability was observed at zirconia concentrations as low as 10(-4) vol % and at an alumina concentration of 10(-2) vol %. The nanoparticles adsorbed onto the microparticle surfaces (confirmed via SEM imaging), which increased the zeta-potential of the silica. Force profile measurements performed with colloidal probe atomic force microscopy showed that the adsorption was effectively irreversible.
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Affiliation(s)
- David Herman
- †Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - John Y Walz
- ‡Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506, United States
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25
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Xie J, Lin J, Wang Y, Li M, Zhang J, Zhou X, He Y. Colloid-associated plutonium aged at room temperature: evaluating its transport velocity in saturated coarse-grained granites. JOURNAL OF CONTAMINANT HYDROLOGY 2015; 172:24-32. [PMID: 25462640 DOI: 10.1016/j.jconhyd.2014.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 10/08/2014] [Accepted: 10/23/2014] [Indexed: 06/04/2023]
Abstract
The fate and transport of colloidal contaminants in natural media are complicated by physicochemical properties of the contaminants and heterogeneous characteristics of the media. Size and charge exclusion are two key microscopic mechanisms dominating macroscopic transport velocities. Faster velocities of colloid-associated actinides than that of (3)H2O were consistently indicated in many studies. However, dissociation/dissolution of these sorbed actinides (e.g., Pu and Np), caused by their redox reactions on mineral surfaces, possibly occurred under certain chemical conditions. How this dissolution is related to transport velocities remains unanswered. In this study, aging of the colloid-associated Pu (pseudo-colloid) at room temperature and transport through the saturated coarse-grained granites were performed to study whether Pu could exhibit slower velocity than that of (3)H2O (UPu/UT <1). The results show that oxidative dissolution of Pu(IV) associated with the surfaces of colloidal granite particles took place during the aging period. The relative velocity of UPu/UT declined from 1.06 (unaged) to 0.745 (135 d) over time. Size exclusion limited to the uncharged nano-sized particles could not explain such observed UPu/UT <1. Therefore, the decline in UPu/UT was ascribed to the presence of electrostatic attraction between the negatively charged wall of granite pore channels and the Pu(V)O2(+), as evidenced by increasing Pu(V)O2(+) concentrations in the suspensions aged in sealed vessels. As a result of this attraction, Pu(V)O2(+) was excluded from the domain closer to the centerline of pore channels. This reveals that charge exclusion played a more important role in dominating UPu than the size exclusion under the specific conditions, where oxidative dissolution of colloid-associated Pu(IV) was observed in the aged suspensions.
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Affiliation(s)
- Jinchuan Xie
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China.
| | - Jianfeng Lin
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China
| | - Yu Wang
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China
| | - Mei Li
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China
| | - Jihong Zhang
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China
| | - Xiaohua Zhou
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China
| | - Yifeng He
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China
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26
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Yu D, Yang H, Wang H, Cui Y, Yang G, Zhang J, Wang J. Interactions between colloidal particles in the presence of an ultrahighly charged amphiphilic polyelectrolyte. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:14512-14521. [PMID: 25397589 DOI: 10.1021/la503033k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A novel amphiphilic polyelectrolyte denoted as PAGC8 and a traditional amphiphilic polyelectrolyte denoted as PASC8 were prepared. PAGC8 consisted of gemini-type surfactant segment based on 1,3-bis (N,N-dimethyl-N-octylammonium)-2-propyl acrylate dibromide, while PASC8 incorporated acryloyloxyethyl-N,N-dimethyl-N-dodecylammonium bromide as single chain surfactant units within its repeat unit structure. Turbidity, stability, and zeta potential measurements were performed in the presence of PAGC8 and PASC8, respectively, to evaluate their effectiveness in inducing solid/liquid separations. It was found that the maximum transmittance was observed before the zeta potential values reached the isoelectric point, implying that not only charge neutralization but also charge-patch mechanism contributed to the separation process. Colloid probe atomic force microscopy technique was introduced to directly determine the interactions between surfaces in the presence of ultrahighly charged amphiphilic polyelectrolyte. On the basis of the AFM results, we have successfully interpreted the influence of the charge density of the polyelectrolytes on the phase stability. Electrostatic interaction played the dominant role in the flocculation processes, although both electrostatic interaction and hydrophobic effect provided contributions to the colloidal dispersions. The attractions upon surfaces approach in the case of PAGC8 were significantly larger than that of PASC8 due to the higher charge density. The strong peeling events upon retraction in the presence of PAGC8 implied that the hydrophobic effect was stronger than that of PASC8, which displayed the loose pulling events. A strong attraction was identified at shorter separation distances for both systems. However, these interactions cannot be successfully described by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloid stability due to the participation of charge-patch and strong hydrophobic effect. To account for the additional interactions, we proposed an extended DLVO empirical model to explain the non-DLVO forces in the systems. A reasonable physical model was also proposed to further describe the interactions between surfaces in the two amphiphilic polyelectrolyte systems.
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Affiliation(s)
- Danfeng Yu
- Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences , No. 2, 1st North Street, Zhongguancun, Beijing 100190, P. R. China
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Lin F, Esmaeili P, Long J, Bara B, Yeung A. Random charge variations at the bitumen–water interface: Characterization by autocorrelation. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.03.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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28
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Pazmino E, Trauscht J, Dame B, Johnson WP. Power law size-distributed heterogeneity explains colloid retention on soda lime glass in the presence of energy barriers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:5412-5421. [PMID: 24773424 DOI: 10.1021/la501006p] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This article concerns reading the nanoscale heterogeneity thought responsible for colloid retention on surfaces in the presence of energy barriers (unfavorable attachment conditions). We back out this heterogeneity on glass surfaces by comparing mechanistic simulations incorporating discrete heterogeneity with colloid deposition experiments performed across a comprehensive set of experimental conditions. Original data is presented for attachment to soda lime glass for three colloid sizes (0.25, 1.1, and 1.95 μm microspheres) under a variety of ionic strengths and fluid velocities in an impinging jet system. A comparison of mechanistic particle trajectory simulations incorporating discrete surface heterogeneity represented by nanoscale zones of positive charge (heterodomains) indicates that a power law size distribution of heterodomains ranging in size from 120 to 60 nm in radius was able to explain the observed retention for all conditions examined. In contrast, uniform and random placement of single-sized heterodomains failed to capture experimentally observed colloid retention across the range of conditions examined.
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Affiliation(s)
- Eddy Pazmino
- Department of Geology and Geophysics, University of Utah , Salt Lake City, Utah 84112, United States
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Perni S, Preedy EC, Prokopovich P. Success and failure of colloidal approaches in adhesion of microorganisms to surfaces. Adv Colloid Interface Sci 2014; 206:265-74. [PMID: 24342736 DOI: 10.1016/j.cis.2013.11.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/12/2013] [Accepted: 11/13/2013] [Indexed: 12/31/2022]
Abstract
Biofilms are communities of cells attached to surfaces, their contributions to biological process may be either a benefit or a threat depending on the microorganism involved and on the type of substrate and environment. Biofilm formation is a complex series of steps; due to the size of microorganisms, the initial phase of biofilm formation, the bacterial adhesion to the surface, has been studied and modeled using theories developed in colloidal science. In this review the application of approaches such as Derjaguin, Landau, Verwey, Overbeek (DLVO) theory and its extended version (xDLVO), to bacterial adhesion is described along with the suitability and applicability of such approaches to the investigation of the interface phenomena regulating cells adhesion. A further refinement of the xDLVO theory encompassing the brush model is also discussed. Finally, the evidences of phenomena neglected in colloidal approaches, such as surface heterogeneity and fluid flow, likely to be the source of failure are defined.
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30
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Xie J, Lin J, Zhou X, Li M, Zhou G. Plutonium partitioning in three-phase systems with water, colloidal particles, and granites: new insights into distribution coefficients. CHEMOSPHERE 2014; 99:125-133. [PMID: 24280054 DOI: 10.1016/j.chemosphere.2013.10.049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 08/26/2013] [Accepted: 10/16/2013] [Indexed: 06/02/2023]
Abstract
The traditional sorption experiments commonly treated the colloid-associated species of low-solubility contaminants as immobile species resulted from the centrifugation or ultrafiltration, and then solid/liquid distribution coefficients (Ks/d) were determined. This may lead to significantly underestimated mobility of the actinides in subsurface environments. Accordingly, we defined a new distribution coefficient (Ks/d+c) to more adequately describe the mobile characteristics of colloidal species. The results show that under alkaline aqueous conditions the traditional Ks/d was 2-3 orders of magnitude larger than the Ks/d+c involving the colloidal species of (239)Pu. The colloid/liquid distribution coefficients Kc/d≫0 (∼10(6)mL/g) revealed strong competition of the colloidal granite particles with the granite grains for Pu. The distribution percentages of Pu in the three-phase systems, depending on various conditions such as particle concentrations, Na(+) concentrations, pH and time, were determined. Moreover, we developed the thermodynamic and kinetic complexation models to explore the interaction of Pu with the particle surfaces.
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Affiliation(s)
- Jinchuan Xie
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China.
| | - Jianfeng Lin
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China
| | - Xiaohua Zhou
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China
| | - Mei Li
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China
| | - Guoqing Zhou
- Northwest Institute of Nuclear Technology, P.O. Box 69-14, Xi'an City, Shanxi Province 710024, PR China
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31
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Shen C, Lazouskaya V, Zhang H, Li B, Jin Y, Huang Y. Influence of surface chemical heterogeneity on attachment and detachment of microparticles. Colloids Surf A Physicochem Eng Asp 2013. [DOI: 10.1016/j.colsurfa.2013.04.048] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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32
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Ben-Yaakov D, Andelman D, Diamant H. Interaction between heterogeneously charged surfaces: surface patches and charge modulation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:022402. [PMID: 23496521 DOI: 10.1103/physreve.87.022402] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Indexed: 06/01/2023]
Abstract
When solid surfaces are immersed in aqueous solutions, some of their charges can dissociate and leave behind charged patches on the surface. Although the charges are distributed heterogeneously on the surface, most of the theoretical models treat them as homogeneous. For overall non-neutral surfaces, the assumption of surface charge homogeneity is rather reasonable since the leading terms of two such interacting surfaces depend on the nonzero average charge. However, for overall neutral surfaces the nature of the surface charge distribution is crucial in determining the intersurface interaction. In the present work we study the interaction between two charged surfaces across an aqueous solution for several charge distributions. The analysis is preformed within the framework of the linearized Poisson-Boltzmann theory. For periodic charge distributions the interaction is found to be repulsive at small separations, unless the two surface distributions are completely out-of-phase with respect to each other. For quenched random charge distributions we find that due to the presence of the ionic solution in between the surfaces, the intersurface repulsion dominates over the attraction in the linear regime of the Poisson-Boltzmann theory. The effect of quenched charge heterogeneity is found to be particularly substantial in the case of large charged domains.
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Affiliation(s)
- Dan Ben-Yaakov
- Raymond & Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
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33
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Henry C, Minier JP, Lefèvre G. Towards a description of particulate fouling: from single particle deposition to clogging. Adv Colloid Interface Sci 2012; 185-186:34-76. [PMID: 23141134 DOI: 10.1016/j.cis.2012.10.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 09/19/2012] [Accepted: 10/02/2012] [Indexed: 10/27/2022]
Abstract
Particulate fouling generally arises from the continuous deposition of colloidal particles on initially clean surfaces, a process which can even lead to a complete blockage of the fluid cross-section. In the present paper, the initial stages of the fouling process (which include single-particle deposition and reentrainment) are first addressed and current modelling state-of-the-art for particle-turbulence and particle-wall interactions is presented. Then, attention is specifically focused on the later stages (which include multilayer formation, clogging and blockage). A detailed review of experimental works brings out the essential mechanisms occurring during these later stages: as for the initial stages, it is found that clogging results from the competition between particle-fluid, particle-surface and particle-particle interactions. Numerical models that have been proposed to reproduce the later stages of fouling are then assessed and a new Lagrangian stochastic approach to clogging in industrial cases is detailed. These models further confirm that, depending on hydrodynamical conditions (the flow velocity), fluid characteristics (such as the ionic strength) as well as particle and substrate properties (such as zeta potentials), particle deposition can lead to the formation of either a single monolayer or multilayers. The present paper outlines also future numerical developments and experimental works that are needed to complete our understanding of the later stages of the fouling process.
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Leite FL, Bueno CC, Da Róz AL, Ziemath EC, Oliveira ON. Theoretical models for surface forces and adhesion and their measurement using atomic force microscopy. Int J Mol Sci 2012. [PMID: 23202925 PMCID: PMC3497299 DOI: 10.3390/ijms131012773] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The increasing importance of studies on soft matter and their impact on new technologies, including those associated with nanotechnology, has brought intermolecular and surface forces to the forefront of physics and materials science, for these are the prevailing forces in micro and nanosystems. With experimental methods such as the atomic force spectroscopy (AFS), it is now possible to measure these forces accurately, in addition to providing information on local material properties such as elasticity, hardness and adhesion. This review provides the theoretical and experimental background of afs, adhesion forces, intermolecular interactions and surface forces in air, vacuum and in solution.
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Affiliation(s)
- Fabio L. Leite
- Nanoneurobiophysics Research Group, Department of Physics, Chemistry and Mathematics, Federal University of São Carlos (UFSCar), P.O. Box 3031, CEP 18052-780, Sorocaba, São Paulo, Brazil; E-Mails: (C.C.B.); (A.L.D.R.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +55-015-3229-6014; Fax: +55-015-3229-5902
| | - Carolina C. Bueno
- Nanoneurobiophysics Research Group, Department of Physics, Chemistry and Mathematics, Federal University of São Carlos (UFSCar), P.O. Box 3031, CEP 18052-780, Sorocaba, São Paulo, Brazil; E-Mails: (C.C.B.); (A.L.D.R.)
| | - Alessandra L. Da Róz
- Nanoneurobiophysics Research Group, Department of Physics, Chemistry and Mathematics, Federal University of São Carlos (UFSCar), P.O. Box 3031, CEP 18052-780, Sorocaba, São Paulo, Brazil; E-Mails: (C.C.B.); (A.L.D.R.)
| | - Ervino C. Ziemath
- Institute of Geosciences and Exact Sciences, São Paulo State University (UNESP), P.O. Box 178, CEP 13550-970, Rio Claro, São Paulo, Brazil; E-Mail:
| | - Osvaldo N. Oliveira
- Institute of Physics of São Carlos, University of São Paulo (USP), P.O. Box 369, CEP 13560-970, São Carlos, São Paulo, Brazil; E-Mail:
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Silica-iron oxide magnetic nanoparticles modified for gene delivery: a search for optimum and quantitative criteria. Pharm Res 2012; 29:1344-65. [PMID: 22222384 DOI: 10.1007/s11095-011-0661-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 12/19/2011] [Indexed: 01/01/2023]
Abstract
PURPOSE To optimize silica-iron oxide magnetic nanoparticles with surface phosphonate groups decorated with 25-kD branched polyethylenimine (PEI) for gene delivery. METHODS Surface composition, charge, colloidal stabilities, associations with adenovirus, magneto-tranduction efficiencies, cell internalizations, in vitro toxicities and MRI relaxivities were tested for the particles decorated with varying amounts of PEI. RESULTS Moderate PEI-decoration of MNPs results in charge reversal and destabilization. Analysis of space and time resolved concentration changes during centrifugation clearly revealed that at >5% PEI loading flocculation gradually decreases and sufficient stabilization is achieved at >10%. The association with adenovirus occurred efficiently at levels over 5% PEI, resulting in the complexes stable in 50% FCS at a PEI-to-iron w/w ratio of ≥7%; the maximum magneto-transduction efficiency was achieved at 9-12% PEI. Primary silica iron oxide nanoparticles and those with 11.5% PEI demonstrated excellent r(2)* relaxivity values (>600 s(-1)(mM Fe)(-1)) for the free and cell-internalized particles. CONCLUSIONS Surface decoration of the silica-iron oxide nanoparticles with a PEI-to-iron w/w ratio of 10-12% yields stable aqueous suspensions, allows for efficient viral gene delivery and labeled cell detection by MRI.
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Linares EM, Jannuzzi SAV, Galembeck F. Electrostatic contributions in the increased compatibility of polymer blends. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:15199-15205. [PMID: 22008021 DOI: 10.1021/la2029998] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Successful blending of different polymers to make a structural or functional material requires overcoming limitations due to immiscibility and/or incompatibility that arise from large polymer-polymer interfacial tensions. In the case of latex blends, the combination of capillary adhesion during the blended dispersion drying stage with electrostatic adhesion in the final product is an effective strategy to avoid these limitations, which has been extended to a number of polymer blends and composites. This work shows that adhesion of polymer domains in blends made with natural rubber and synthetic latexes is enhanced by electrostatic adhesion that is in turn enhanced by ion migration, according to the results from scanning electric potential microscopy. The additional attractive force between domains improves blend stability and mechanical properties, broadening the possibilities and scope of latex blends, in consonance with the "green chemistry" paradigm. This novel approach based on electrostatic adhesion can be easily extended to multicomponent systems, including nonpolymers.
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Affiliation(s)
- Elisângela M Linares
- Institute of Chemistry, University of Campinas, P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil
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The model of hydrophobic attraction in the framework of classical DLVO forces. Adv Colloid Interface Sci 2011; 168:149-66. [PMID: 21752345 DOI: 10.1016/j.cis.2011.06.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Revised: 06/13/2011] [Accepted: 06/14/2011] [Indexed: 11/22/2022]
Abstract
The present article focuses on the analysis of experimental data and interpreting of the influence of water depletion near hydrophobic particles and nanobubbles formed on their surface or in the space between them on van der Waals and electrostatic components of interparticle interaction. It is shown that the difference between simplified and more detailed models of DLVO forces explains the nature and main characteristics of hydrophobic attraction.
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