1
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Ozkul S, Arbabzadeh O, Bisselink RJM, Kuipers NJM, Bruning H, Rijnaarts HHM, Dykstra JE. Selective adsorption in ion exchange membranes: The effect of solution ion composition on ion partitioning. WATER RESEARCH 2024; 254:121382. [PMID: 38471202 DOI: 10.1016/j.watres.2024.121382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/23/2024] [Accepted: 02/24/2024] [Indexed: 03/14/2024]
Abstract
Electrodialysis is a water desalination technology that enables selective separation of ions, making it a promising solution for sustainable water reuse. The selectivity of the process is mainly determined by the properties of ion exchange membranes that can vary depending on the composition of ions in water, such as water uptake and charge density. In this work, we studied selective adsorption of Na+ and K+ ions in various ion exchange membranes considering the effect of solution ion composition on membrane water volume fraction. For that purpose, we conducted membrane adsorption experiments using solutions with Na+ and K+ ions with different ion compositions including Li+, Ca2+ or Mg2+ ions at different concentrations (0.001 - 0.25 M). The experiments showed that with the total ion concentration and the amount of divalent ions in solution, the membrane water volume fraction decreases while the selective adsorption of the smaller (hydrated) K+ ions over the Na+ ions in the membrane increases. We developed a theoretical framework based on Boublik-Mansoori-Carnahan-Starling-Leland (BMCSL) theory to describe the effect of membrane water volume fraction on selective adsorption of the ions by including volumetric effects, such as size exclusion. The developed framework was used to describe ion partitioning results of the membrane adsorption experiments. In addition, the effect of solution ion composition on selective ion removal during electrodialysis operation was evaluated using experimental data and theoretical calculations. The results of this study show that considering volumetric effects can improve the ion partitioning description in ion exchange membranes for solutions with various ion compositions.
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Affiliation(s)
- S Ozkul
- Environmental Technology, Wageningen University & Research, Bornse Weilanden 9, Wageningen 6708 WG, the Netherlands
| | - O Arbabzadeh
- Environmental Technology, Wageningen University & Research, Bornse Weilanden 9, Wageningen 6708 WG, the Netherlands; Department of Civil, Environmental and Architectural Engineering, University of Padua, Via Marzolo 9, Padua 35131, Italy
| | - R J M Bisselink
- Food and Biobased Research, Wageningen University & Research, Bornse Weilanden 9, Wageningen 6708 WG, the Netherlands
| | - N J M Kuipers
- Food and Biobased Research, Wageningen University & Research, Bornse Weilanden 9, Wageningen 6708 WG, the Netherlands
| | - H Bruning
- Environmental Technology, Wageningen University & Research, Bornse Weilanden 9, Wageningen 6708 WG, the Netherlands
| | - H H M Rijnaarts
- Environmental Technology, Wageningen University & Research, Bornse Weilanden 9, Wageningen 6708 WG, the Netherlands
| | - J E Dykstra
- Environmental Technology, Wageningen University & Research, Bornse Weilanden 9, Wageningen 6708 WG, the Netherlands.
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2
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Lukiev IV, Mogelnitskaya YA, Mikhailov IV, Darinskii AA. Chains Stiffness Effect on the Vertical Segregation of Mixed Polymer Brushes in Selective Solvent. Polymers (Basel) 2023; 15:polym15030644. [PMID: 36771945 PMCID: PMC9919982 DOI: 10.3390/polym15030644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/15/2023] [Accepted: 01/24/2023] [Indexed: 01/28/2023] Open
Abstract
The microstructure of the binary polymer brushes in the selective solvent was studied using the numerical lattice self-consisting field approach. The case was considered when the selectivity to the solvent (the Flory-Huggins parameter χ) was varied only for one type of chains (responsive chains) while the others (non-responsive chains) remained hydrophilic (χ = 0). In such a brush, with an increase in the hydrophobicity of the responsive chains, a transition occurs between two two-layer microstructures. In the initial state the ends of the longer responsive chains are located near the external surface of the brush and those of non-responsive chains are inside the brush. When the hydrophobicity of the responsive chains becomes high enough then the reversed two-layer microstructure is formed, when the ends of non-responsive chains are located near the brush surface and the responsive chains collapse on the brush bottom. In contrast to previous works, the stiffness parameter (Kuhn segment length p) for one or for both types of chains was varied and its effect on the mechanism and characteristics of the transition was studied. If the stiffness of only responsive chains increases, then the transition occurs with the formation of an intermediate three-layer microstructure, where a layer of responsive chains is located between layers formed by non-responsive ones. If both types of chains have the same p, then the transition occurs gradually without the formation of an intermediate three-layer microstructure. For both cases, the effect of p on the critical value of χ*, corresponding to the transition point and on the steepness of the transition was investigated.
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Affiliation(s)
- Ivan V. Lukiev
- Center for Chemical Engineering, ITMO University, 197101 St. Petersburg, Russia
| | | | - Ivan V. Mikhailov
- Institute of Macromolecular Compounds, Russian Academy of Sciences, 199004 St. Petersburg, Russia
| | - Anatoly A. Darinskii
- Institute of Macromolecular Compounds, Russian Academy of Sciences, 199004 St. Petersburg, Russia
- Correspondence: ; Tel.: +7-911-280-9517
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3
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Generation of Fermat's spiral patterns by solutal Marangoni-driven coiling in an aqueous two-phase system. Nat Commun 2022; 13:7206. [PMID: 36418301 PMCID: PMC9684484 DOI: 10.1038/s41467-022-34368-5] [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: 03/17/2022] [Accepted: 10/24/2022] [Indexed: 11/27/2022] Open
Abstract
The solutal Marangoni effect is attracting increasing interest because of its fundamental role in many isothermal directional transport processes in fluids, including the Marangoni-driven spreading on liquid surfaces or Marangoni convection within a liquid. Here we report a type of continuous Marangoni transport process resulting from Marangoni-driven spreading and Marangoni convection in an aqueous two-phase system. The interaction between a salt (CaCl2) and an anionic surfactant (sodium dodecylbenzenesulfonate) generates surface tension gradients, which drive the transport process. This Marangoni transport consists of the upward transfer of a filament from a droplet located at the bottom of a bulk solution, coiling of the filament near the surface, and formation of Fermat's spiral patterns on the surface. The bottom-up coiling of the filament, driven by Marangoni convection, may inspire automatic fiber fabrication.
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4
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A nonionic polymer-brush-grafted PVDF membrane to analyse fouling during the filtration of oil/water emulsions. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2021.119644] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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5
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Durmaz EN, Sahin S, Virga E, de Beer S, de Smet LCPM, de Vos WM. Polyelectrolytes as Building Blocks for Next-Generation Membranes with Advanced Functionalities. ACS APPLIED POLYMER MATERIALS 2021; 3:4347-4374. [PMID: 34541543 PMCID: PMC8438666 DOI: 10.1021/acsapm.1c00654] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/10/2021] [Indexed: 05/06/2023]
Abstract
The global society is in a transition, where dealing with climate change and water scarcity are important challenges. More efficient separations of chemical species are essential to reduce energy consumption and to provide more reliable access to clean water. Here, membranes with advanced functionalities that go beyond standard separation properties can play a key role. This includes relevant functionalities, such as stimuli-responsiveness, fouling control, stability, specific selectivity, sustainability, and antimicrobial activity. Polyelectrolytes and their complexes are an especially promising system to provide advanced membrane functionalities. Here, we have reviewed recent work where advanced membrane properties stem directly from the material properties provided by polyelectrolytes. This work highlights the versatility of polyelectrolyte-based membrane modifications, where polyelectrolytes are not only applied as single layers, including brushes, but also as more complex polyelectrolyte multilayers on both porous membrane supports and dense membranes. Moreover, free-standing membranes can also be produced completely from aqueous polyelectrolyte solutions allowing much more sustainable approaches to membrane fabrication. The Review demonstrates the promise that polyelectrolytes and their complexes hold for next-generation membranes with advanced properties, while it also provides a clear outlook on the future of this promising field.
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Affiliation(s)
- Elif Nur Durmaz
- Membrane
Science and Technology, MESA+ Institute for Nanotechnology, Faculty
of Science and Technology, University of
Twente, Enschede 7500 AE, The Netherlands
| | - Sevil Sahin
- Laboratory
of Organic Chemistry, Wageningen University, 6708 WE Wageningen, The Netherlands
| | - Ettore Virga
- Membrane
Science and Technology, MESA+ Institute for Nanotechnology, Faculty
of Science and Technology, University of
Twente, Enschede 7500 AE, The Netherlands
- Wetsus, European
Centre of Excellence for Sustainable Water
Technology, Oostergoweg
9, 8911 MA Leeuwarden, The Netherlands
| | - Sissi de Beer
- Sustainable
Polymer Chemistry Group, Department of Molecules and Materials MESA+
Institute for Nanotechnology, University
of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Louis C. P. M. de Smet
- Laboratory
of Organic Chemistry, Wageningen University, 6708 WE Wageningen, The Netherlands
| | - Wiebe M. de Vos
- Membrane
Science and Technology, MESA+ Institute for Nanotechnology, Faculty
of Science and Technology, University of
Twente, Enschede 7500 AE, The Netherlands
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6
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Gresham IJ, Murdoch TJ, Johnson EC, Robertson H, Webber GB, Wanless EJ, Prescott SW, Nelson ARJ. Quantifying the robustness of the neutron reflectometry technique for structural characterization of polymer brushes. J Appl Crystallogr 2021. [DOI: 10.1107/s160057672100251x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Neutron reflectometry is the foremost technique for in situ determination of the volume fraction profiles of polymer brushes at planar interfaces. However, the subtle features in the reflectometry data produced by these diffuse interfaces challenge data interpretation. Historically, data analyses have used least-squares approaches that do not adequately quantify the uncertainty of the modeled profile and ignore the possibility of other structures that also match the collected data (multimodality). Here, a Bayesian statistical approach is used that permits the structural uncertainty and multimodality to be quantified for polymer brush systems. A free-form model is used to describe the volume fraction profile, minimizing assumptions regarding brush structure, while only allowing physically reasonable profiles to be produced. The model allows the total volume of polymer and the profile monotonicity to be constrained. The rigor of the approach is demonstrated via a round-trip analysis of a simulated system, before it is applied to real data examining the well characterized collapse of a thermoresponsive brush. It is shown that, while failure to constrain the interfacial volume and consider multimodality may result in erroneous structures being derived, carefully constraining the model allows for robust determination of polymer brush compositional profiles. This work highlights that an appropriate combination of flexibility and constraint must be used with polymer brush systems to ensure the veracity of the analysis. The code used in this analysis is provided, enabling the reproduction of the results and the application of the method to similar problems.
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7
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Pan C, Cao X, Tang L, Zhang Y, He H, Yin T, Piao H, Tang X. Phospholipid Complex of ICA and ICA II Prepared by Wet Media Milling for Improving Bioavailability. EUR J LIPID SCI TECH 2018. [DOI: 10.1002/ejlt.201700317] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Caiyun Pan
- School of Pharmacy, Shenyang Pharmaceutical University; 103 Wenhua Road Shenyang 110016 China
| | - Xiuxiu Cao
- School of Pharmacy, Shenyang Pharmaceutical University; 103 Wenhua Road Shenyang 110016 China
| | - Lihua Tang
- School of Pharmacy, Shenyang Pharmaceutical University; 103 Wenhua Road Shenyang 110016 China
| | - Yu Zhang
- School of Pharmacy, Shenyang Pharmaceutical University; 103 Wenhua Road Shenyang 110016 China
| | - Haibing He
- School of Pharmacy, Shenyang Pharmaceutical University; 103 Wenhua Road Shenyang 110016 China
| | - Tian Yin
- School of Pharmacy, Shenyang Pharmaceutical University; 103 Wenhua Road Shenyang 110016 China
| | - Hongyu Piao
- School of Pharmacy, Shenyang Pharmaceutical University; 103 Wenhua Road Shenyang 110016 China
| | - Xing Tang
- School of Pharmacy, Shenyang Pharmaceutical University; 103 Wenhua Road Shenyang 110016 China
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8
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Zhu PW, Chen L. Synergistic Effects of Bound Micelles and Temperature on the Flexibility of Thermoresponsive Polymer Brushes. J Phys Chem B 2016; 120:11595-11606. [PMID: 27750008 DOI: 10.1021/acs.jpcb.6b08696] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The persistence length is a key parameter for the quantitative interpretation of the flexibility of polymers. We have studied complexes composed of a spherical poly(N-isopropylacrylamide) (PNIPAM) brush and a sodium dodecyl sulfate micelle in an effort to characterize the flexibility of tethered PNIPAM below the lower critical solution temperature TLCST. An analytical mean-field model is used to describe the persistence length Lp in a broad range of ψ, the number of bound micelles per chain. The persistence length of micelle-constrained PNIPAM is quantitatively correlated with the thermal energy kBT, electrostatic repulsion fC, and effective excluded-volume parameter νeff. The persistence length per ψ, which depends on T and fC, is found to scale with a synergistic effect fC/(ψkBT). The results reveal that the bound-micelle charges affecting the persistence length are analogous to the fixed charges of polyelectrolytes, though the bound micelles are separated by a large number of neutral monomers. The extension ⟨L⟩ of micelle-constrained PNIPAM decreases as ⟨L⟩ ∼ fC-βF with fC, where βF ≈ 0.58-0.8 depending on ψ, but as the universal power law ⟨L⟩ ∼ (fC/kBT)-0.6 with the synergistic effect fC/(kBT), irrespective of ψ. In spite of the intricate interplay among the multiple components in the system, the extension scales as a function of νeff as ⟨L⟩ ∼ (νeff/ψLp)-βV, where βV ≈ 0.35 for the significant monomer interaction and βV ≈ 0.2 for the weak or negligible monomer interaction.
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Affiliation(s)
- Peng-Wei Zhu
- Department of Materials Science and Engineering and ‡Department of Chemical Engineering, Monash University , Clayton, VIC 3800, Australia
| | - Luguang Chen
- Department of Materials Science and Engineering and ‡Department of Chemical Engineering, Monash University , Clayton, VIC 3800, Australia
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9
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10
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Riley JK, An J, Tilton RD. Ionic Surfactant Binding to pH-Responsive Polyelectrolyte Brush-Grafted Nanoparticles in Suspension and on Charged Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:13680-13689. [PMID: 26649483 DOI: 10.1021/acs.langmuir.5b03757] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The interactions between silica nanoparticles grafted with a brush of cationic poly(2-(dimethylamino) ethyl methacrylate) (SiO2-g-PDMAEMA) and anionic surfactant sodium dodecyl sulfate (SDS) is investigated by dynamic light scattering, electrophoretic mobility, quartz crystal microbalance with dissipation, ellipsometry, and atomic force microscopy. SiO2-g-PDMAEMA exhibits pH-dependent charge and size properties which enable the SDS binding to be probed over a range of electrostatic conditions and brush conformations. SDS monomers bind irreversibly to SiO2-g-PDMAEMA at low surfactant concentrations (∼10(-4) M) while exhibiting a pH-dependent threshold above which cooperative, partially reversible SDS binding occurs. At pH 5, SDS binding induces collapse of the highly charged and swollen brush as observed in the bulk by DLS and on surfaces by QCM-D. Similar experiments at pH 9 suggest that SDS binds to the periphery of the weakly charged and deswollen brush and produces SiO2-g-PDMAEMA/SDS complexes with a net negative charge. SiO2-g-PDMAEMA brush collapse and charge neutralization is further confirmed by colloidal probe AFM measurements, where reduced electrosteric repulsions and bridging adhesion are attributed to effects of the bound SDS. Additionally, sequential adsorption schemes with SDS and SiO2-g-PDMAEMA are used to enhance deposition relative to SiO2-g-PDMAEMA direct adsorption on silica. This work shows that the polyelectrolyte brush configuration responds in a more dramatic fashion to SDS than to pH-induced changes in ionization, and this can be exploited to manipulate the structure of adsorbed layers and the corresponding forces of compression and friction between opposing surfaces.
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Affiliation(s)
| | - Junxue An
- KTH Royal Institute of Technology , School of Chemical Science and Engineering, Department of Chemistry, Surface and Corrosion Science, Stockholm SE-100 44, Sweden
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11
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Yang Z, Tarabara VV, Bruening ML. Adsorption of Anionic or Cationic Surfactants in Polyanionic Brushes and Its Effect on Brush Swelling and Fouling Resistance during Emulsion Filtration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:11790-9. [PMID: 26442835 DOI: 10.1021/acs.langmuir.5b01938] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Atom transfer radical polymerization of ionic monomers from membrane surfaces yields polyelectrolyte brushes that swell in water and repel oil droplets to resist fouling during filtration of oil-in-water emulsions. However, surfactant adsorption to polyelectrolyte brushes may overcome this fouling resistance. This work examines adsorption of cationic and anionic surfactants in polyanionic brushes and the effect of these surfactants on emulsion filtration. In situ ellipsometry with films on flat surfaces shows that brushes composed of poly(3-sulfopropyl methacrylate salts) (pSPMK) swell 280% in water and do not adsorb sodium dodecyl sulfate (SDS). pSPMK-modified microfiltration membranes reject >99.9% of the oil from SDS-stabilized submicron emulsions, and the specific flux through these modified membranes is comparable to that through NF270 nanofiltration membranes. Moreover, the brush-modified membranes show no decline in flux over a 12 h filtration, whereas the flux through NF270 membranes decreases by 98.7%. In contrast, pSPMK brushes adsorb large quantities of cetyltrimethylammonium bromide (CTAB), and at low chain densities the brushes collapse in the presence of this cationic surfactant. Filtration of CTAB-stabilized emulsions through pSPMK-modified membranes gives minimal oil rejection, presumably due to the brush collapse. Thus, the fouling resistance of polyelectrolyte brush-modified membranes clearly depends on the surfactant composition in a particular emulsion.
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Affiliation(s)
- Zhefei Yang
- Department of Chemistry and ‡Department of Civil and Environmental Engineering, Michigan State University , East Lansing, Michigan 48824, United States
| | - Volodymyr V Tarabara
- Department of Chemistry and ‡Department of Civil and Environmental Engineering, Michigan State University , East Lansing, Michigan 48824, United States
| | - Merlin L Bruening
- Department of Chemistry and ‡Department of Civil and Environmental Engineering, Michigan State University , East Lansing, Michigan 48824, United States
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12
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Zhang R, Ma S, Wei Q, Ye Q, Yu B, van der Gucht J, Zhou F. The Weak Interaction of Surfactants with Polymer Brushes and Its Impact on Lubricating Behavior. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b01267] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Ran Zhang
- State Key Laboratory
of Solid Lubrication Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Rd, 730000 Lanzhou, China
- University
of Chinese Academy of Sciences, 100049 Beijing, China
| | - Shuanhong Ma
- State Key Laboratory
of Solid Lubrication Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Rd, 730000 Lanzhou, China
- University
of Chinese Academy of Sciences, 100049 Beijing, China
| | - Qiangbing Wei
- State Key Laboratory
of Solid Lubrication Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Rd, 730000 Lanzhou, China
| | - Qian Ye
- State Key Laboratory
of Solid Lubrication Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Rd, 730000 Lanzhou, China
| | - Bo Yu
- State Key Laboratory
of Solid Lubrication Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Rd, 730000 Lanzhou, China
| | - Jasper van der Gucht
- Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, NL-6703
HB Wageningen, The Netherlands
| | - Feng Zhou
- State Key Laboratory
of Solid Lubrication Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Tianshui Middle Rd, 730000 Lanzhou, China
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13
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Romeis D, Sommer JU. Binary and Bidisperse Polymer Brushes: Coexisting Surface States. ACS APPLIED MATERIALS & INTERFACES 2015; 7:12496-12504. [PMID: 25723841 DOI: 10.1021/am507959k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In the present work, we consider polydispersity effects on a mixed polymer brush. Two types of polymer chains with different solvent selectivity being densely grafted together onto an impenetrable surface are forming a binary mixed polymer brush. Using a numerical quasi off-lattice self-consistent field method for heterogeneous chains we study the brush profile upon varying the strength of solvent selectivity (e.g., temperature) and the degree of polymerization of the two chain types (N1 and N2, respectively). For a monodisperse brush (N1 = N2) it is well-known, that the two types of polymers segregate into a two-layer structure, if the difference in solvent selectivity is increased. The state where the chains exposed to their good solvent forming the top layer of the brush can be frustrated for shorter chains and an inversion of the layering takes place. In the inverted state, the top layer is formed by long chains exposed to poor solvent covering the layer of shorter chains. By varying the solvent selectivity of the long chains we show that coexistence of the two states occurs,which indicates a discontinuous phase transition scenario for the switching process. We consider further the case of a very low fraction of short chains and find these chains to undergo a conformational transition of first order from a "coil" state, found deep inside the compact brush layer, to a "flower" state, stretching to the top of the brush upon varying the strength of the solvent selectivity. At the transition both states are found to be quasi-stable with an energy barrier of the order of the chain length in units of kBT. The discontinuous nature of the switching process by combining solvent selectivity and bidispersity can be of high interest for the creation of stimuli-responsive surfaces.
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Affiliation(s)
- Dirk Romeis
- †Leibniz-Institut fuer Polymerforschung Dresden e.V., Hohe Strasse 6, 01069 Dresden, Germany
| | - Jens-Uwe Sommer
- †Leibniz-Institut fuer Polymerforschung Dresden e.V., Hohe Strasse 6, 01069 Dresden, Germany
- ‡Institut fuer Theoretische Physik, Technische Universitaet Dresden, 01069 Dresden, Germany
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14
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Association of anionic surfactant and physisorbed branched brush layers probed by neutron and optical reflectometry. J Colloid Interface Sci 2015; 440:245-52. [DOI: 10.1016/j.jcis.2014.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/29/2014] [Accepted: 11/02/2014] [Indexed: 11/18/2022]
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15
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Spruijt E, Biesheuvel PM, de Vos WM. Adsorption of charged and neutral polymer chains on silica surfaces: the role of electrostatics, volume exclusion, and hydrogen bonding. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:012601. [PMID: 25679636 DOI: 10.1103/physreve.91.012601] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Indexed: 06/04/2023]
Abstract
We develop an off-lattice (continuum) model to describe the adsorption of neutral polymer chains and polyelectrolytes to surfaces. Our continuum description allows taking excluded volume interactions between polymer chains and ions directly into account. To implement those interactions, we use a modified hard-sphere equation of state, adapted for mixtures of connected beads. Our model is applicable to neutral, charged, and ionizable surfaces and polymer chains alike and accounts for polarizability effects of the adsorbed layer and chemical interactions between polymer chains and the surface. We compare our model predictions to data of a classical system for polymer adsorption: neutral poly(N-vinylpyrrolidone) (PVP) on silica surfaces. The model shows that PVP adsorption on silica is driven by surface hydrogen bonding with an effective maximum binding energy of about 1.3k(B)T per PVP segment at low pH. As the pH increases, the Si-OH groups become increasingly dissociated, leading to a lower capacity for H bonding and simultaneous counterion accumulation and volume exclusion close to the surface. Together these effects result in a characteristic adsorption isotherm, with the adsorbed amount dropping sharply at a critical pH. Using this model for adsorption data on silica surfaces cleaned by either a piranha solution or an O(2) plasma, we find that the former have a significantly higher density of silanol groups.
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Affiliation(s)
- Evan Spruijt
- ESPCI ParisTech, Physique et Mécanique des Milieux Hétérogènes, UMR 7636 du CNRS, 10 rue Vauquelin, 75005 Paris, France and Radboud University Nijmegen, Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - P M Biesheuvel
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands and Wageningen University, Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, 6703 HB The Netherlands
| | - Wiebe M de Vos
- University of Twente, Membrane Science and Technology, MESA+ Institute of Nanotechnology, P.O. Box 217, 7500 AE Enschede, The Netherlands
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16
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Zhu PW. Effects of Sodium Dodecyl Sulfate on Structures of Poly(N-isopropylacrylamide) at the Particle Surface. J Phys Chem B 2014; 119:359-71. [DOI: 10.1021/jp510350w] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Peng Wei Zhu
- Department of Materials Engineering, Monash University, Clayton, VIC 3800, Australia
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17
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Cui W, Su CF, Merlitz H, Wu CX, Sommer JU. Structure of Dendrimer Brushes: Mean-Field Theory and MD Simulations. Macromolecules 2014. [DOI: 10.1021/ma500129h] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Wei Cui
- Department
of Physics and ITPA, Xiamen University, Xiamen 361005, P. R. China
| | - Chan-Fei Su
- Department
of Physics and ITPA, Xiamen University, Xiamen 361005, P. R. China
| | - Holger Merlitz
- Department
of Physics and ITPA, Xiamen University, Xiamen 361005, P. R. China
- Leibniz-Institut für Polymerforschung Dresden, 01069 Dresden, Germany
| | - Chen-Xu Wu
- Department
of Physics and ITPA, Xiamen University, Xiamen 361005, P. R. China
| | - Jens-Uwe Sommer
- Leibniz-Institut für Polymerforschung Dresden, 01069 Dresden, Germany
- Institute
for Theoretical Physics, Technische Universität Dresden, 01069 Dresden, Germany
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18
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Wang H, Zhang H, Yuan S, Liu C, Xu Z. Molecular dynamics study of the adsorption of anionic surfactant in a nonionic polymer brush. J Mol Model 2014; 20:2267. [PMID: 24831533 DOI: 10.1007/s00894-014-2267-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/23/2014] [Indexed: 11/26/2022]
Affiliation(s)
- Hua Wang
- Key Lab of Colloid and Interface Chemistry, Shandong University, Jinan, 250100, China
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Spruijt E, Biesheuvel PM. Sedimentation dynamics and equilibrium profiles in multicomponent mixtures of colloidal particles. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:075101. [PMID: 24451477 DOI: 10.1088/0953-8984/26/7/075101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this paper we give a general theoretical framework that describes the sedimentation of multicomponent mixtures of particles with sizes ranging from molecules to macroscopic bodies. Both equilibrium sedimentation profiles and the dynamic process of settling, or its converse, creaming, are modeled. Equilibrium profiles are found to be in perfect agreement with experiments. Our model reconciles two apparently contradicting points of view about buoyancy, thereby resolving a long-lived paradox about the correct choice of the buoyant density. On the one hand, the buoyancy force follows necessarily from the suspension density, as it relates to the hydrostatic pressure gradient. On the other hand, sedimentation profiles of colloidal suspensions can be calculated directly using the fluid density as apparent buoyant density in colloidal systems in sedimentation-diffusion equilibrium (SDE) as a result of balancing gravitational and thermodynamic forces. Surprisingly, this balance also holds in multicomponent mixtures. This analysis resolves the ongoing debate of the correct choice of buoyant density (fluid or suspension): both approaches can be used in their own domain. We present calculations of equilibrium sedimentation profiles and dynamic sedimentation that show the consequences of these insights. In bidisperse mixtures of colloids, particles with a lower mass density than the homogeneous suspension will first cream and then settle, whereas particles with a suspension-matched mass density form transient, bimodal particle distributions during sedimentation, which disappear when equilibrium is reached. In all these cases, the centers of the distributions of the particles with the lowest mass density of the two, regardless of their actual mass, will be located in equilibrium above the so-called isopycnic point, a natural consequence of their hard-sphere interactions. We include these interactions using the Boublik-Mansoori-Carnahan-Starling-Leland (BMCSL) equation of state. Finally, we demonstrate that our model is not limited to hard spheres, by extending it to charged spherical particles, and to dumbbells, trimers and short chains of connected beads.
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Affiliation(s)
- E Spruijt
- Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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20
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21
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Galama A, Post J, Cohen Stuart M, Biesheuvel P. Validity of the Boltzmann equation to describe Donnan equilibrium at the membrane–solution interface. J Memb Sci 2013. [DOI: 10.1016/j.memsci.2013.04.022] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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22
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Romeis D, Sommer JU. Conformational switching of modified guest chains in polymer brushes. J Chem Phys 2013; 139:044910. [DOI: 10.1063/1.4816125] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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23
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Ho YF, Shendruk TN, Slater GW, Hsiao PY. Structure of polyelectrolyte brushes subject to normal electric fields. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:2359-2370. [PMID: 23347275 DOI: 10.1021/la304267f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Molecular dynamic simulations of salt-free polyelectrolyte brushes subject to external fields applied normal to the grafting substrate reveal the three-dimensional monomer and counterion distributions. It is found that below a critical electric field, local electroneutrality holds for densely grafted brushes and the brush height remains independent of field intensity. Above this critical field (which scales as 1/3 with grafting density) brush height increases smoothly, and the fraction of condensed counterions decreases. The brush bifurcates into two subpopulations of stretched and collapsed chains when the grafting density is not low. At intermediate grafting densities, the majority of chains are stretched and the minority are nonstretched. At high grafting densities bifurcation and brush height growth occur consecutively. The majority of the chains are nonstretched at high grafting densities. Although not observed prior to overstretching of the chain model, it is predicted that the two subpopulations will re-merge to a single highly stretched phase when field intensity reaches a third critical value. The ability to control subpopulations of chains suggests that utilizing electric fields normal to polyelectrolyte brushes holds potential as controllable gates in microfluidic devices.
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Affiliation(s)
- Yu-Fan Ho
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan 300, ROC
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24
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Merlitz H, Cui W, Wu CX, Sommer JU. Semianalytical Mean-Field Model for Starlike Polymer Brushes in Good Solvent. Macromolecules 2013. [DOI: 10.1021/ma302417j] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Holger Merlitz
- Department
of Physics and ITPA, Xiamen University,
Xiamen 361005, P. R. China
- Leibniz-Institut für Polymerforschung Dresden, 01069 Dresden,
Germany
| | - Wei Cui
- Department
of Physics and ITPA, Xiamen University,
Xiamen 361005, P. R. China
| | - Chen-Xu Wu
- Department
of Physics and ITPA, Xiamen University,
Xiamen 361005, P. R. China
| | - Jens-Uwe Sommer
- Leibniz-Institut für Polymerforschung Dresden, 01069 Dresden,
Germany
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25
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Jalili K, Abbasi F, Milchev A. Dynamic Compression of in Situ Grown Living Polymer Brush: Simulation and Experiment. Macromolecules 2012. [DOI: 10.1021/ma301743r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K. Jalili
- Max Planck Institute for Polymer Research, 10 Ackermannweg, 55128 Mainz,
Germany
- Institute of Polymeric
Materials, Sahand University of Technology, P.O. Box 51335-1996,
Tabriz, Iran
| | - F. Abbasi
- Institute of Polymeric
Materials, Sahand University of Technology, P.O. Box 51335-1996,
Tabriz, Iran
| | - A. Milchev
- Max Planck Institute for Polymer Research, 10 Ackermannweg, 55128 Mainz,
Germany
- Institute for
Physical Chemistry, Bulgarian Academy of Science, 1113 Sofia, Bulgaria
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26
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Binder K, Milchev A. Polymer brushes on flat and curved surfaces: How computer simulations can help to test theories and to interpret experiments. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/polb.23168] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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27
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Cattoz B, Cosgrove T, Crossman M, Prescott SW. Surfactant-mediated desorption of polymer from the nanoparticle interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:2485-2492. [PMID: 22188133 DOI: 10.1021/la204512d] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The surfactant-mediated desorption of adsorbed poly(vinylpyrrolidone), PVP, from anionic silica surfaces by sodium dodecyl sulfate, SDS, was observed. While photon correlation spectroscopy shows that the size of the polymer-surfactant-particle ensemble grows with added SDS, a reduction in the near-surface polymer concentration is measured by solvent relaxation NMR. Volume fraction profiles of the polymer layer extracted from small-angle neutron scattering experiments illustrate that the adsorbed polymer layer has become more diffuse and the polymer chains more elongated as a result of the addition of SDS. The total adsorbed amount is shown to decrease due to Coulombic repulsion between the surfactant-polymer complexes and between the complexes and the anionic silica surface.
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Affiliation(s)
- Beatrice Cattoz
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
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28
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Romeis D, Merlitz H, Sommer JU. A new numerical approach to dense polymer brushes and surface instabilities. J Chem Phys 2012; 136:044903. [DOI: 10.1063/1.3676657] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Cao Q, Zuo C, Li L. Electrostatic binding of oppositely charged surfactants to spherical polyelectrolyte brushes. Phys Chem Chem Phys 2011; 13:9706-15. [DOI: 10.1039/c0cp02171g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Migliorini G. On the Corrections to Strong-Stretching Theory for End-Confined, Charged Polymers in a Uniform Electric Field. Macromolecules 2010. [DOI: 10.1021/ma101722n] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gabriele Migliorini
- Department of Mathematics and Statistics, University of Reading, Whiteknights, Reading RG6 6AX, United Kingdom
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32
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Elliott IG, Kuhl TL, Faller R. Molecular Simulation Study of the Structure of High Density Polymer Brushes in Good Solvent. Macromolecules 2010. [DOI: 10.1021/ma101252c] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ian G. Elliott
- Department of Chemical Engineering and Materials Science, University of California at Davis, Davis, California, 95616
| | - Tonya L. Kuhl
- Department of Chemical Engineering and Materials Science, University of California at Davis, Davis, California, 95616
| | - Roland Faller
- Department of Chemical Engineering and Materials Science, University of California at Davis, Davis, California, 95616
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Nejadnik MR, Garcia CD. Staining proteins: a simple method to increase the sensitivity of ellipsometric measurements in adsorption studies. Colloids Surf B Biointerfaces 2010; 82:253-7. [PMID: 20833003 DOI: 10.1016/j.colsurfb.2010.08.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Accepted: 08/16/2010] [Indexed: 10/19/2022]
Abstract
This communication describes a simple way to improve the sensitivity of spectroscopic ellipsometry, when applied to monitor the adsorption of proteins to solid surfaces. The method described herein is based on the reaction of a commercially available dye (Coomassie brilliant blue G) with the adsorbed proteins and the subsequent analysis by spectroscopic ellipsometry. In order to demonstrate the potential advantages of this method, the adsorption of bovine serum albumin to an antifouling coating was also investigated. According to our results, the modification with the dye significantly affects the optical properties of the adsorbed protein layer, which can be represented using a simple optical model (Lorentz). In general, the proposed modification increases the sensitivity of the detection by 2.5 ± 0.4-fold and enables the analysis of thin layers of adsorbed protein not obtainable by conventional methods. These results particularly reveal the importance of the proposed modification for the evaluation of low adsorbing substrates and antifouling coatings.
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Affiliation(s)
- M Reza Nejadnik
- Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA
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34
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He SZ, Merlitz H, Chen L, Sommer JU, Wu CX. Polyelectrolyte Brushes: MD Simulation and SCF Theory. Macromolecules 2010. [DOI: 10.1021/ma101230v] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Su-zhen He
- Department of Physics and ITPA, Xiamen University, Xiamen 361005, P.R. China
- Department of Electronic Engineering, Putian University, Putian 351100, P.R. China
| | - Holger Merlitz
- Department of Physics and ITPA, Xiamen University, Xiamen 361005, P.R. China
- Leibniz-Institut für Polymerforschung Dresden, 01069 Dresden, Germany
| | - Long Chen
- Department of Physics and ITPA, Xiamen University, Xiamen 361005, P.R. China
| | - Jens-Uwe Sommer
- Leibniz-Institut für Polymerforschung Dresden, 01069 Dresden, Germany
| | - Chen-Xu Wu
- Department of Physics and ITPA, Xiamen University, Xiamen 361005, P.R. China
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35
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Halperin A, Kröger M. Ternary protein adsorption onto brushes: strong versus weak. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:11621-34. [PMID: 19673469 DOI: 10.1021/la9008569] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Attractive interactions between proteins and polyethylene glycol (PEG) give rise to ternary adsorption within PEG brushes. Experimental evidence suggests two ternary adsorption modes: (i) weak, due to nonspecific weak attraction between PEG monomers and the surface of the protein, as exemplified by serum albumin and (ii) strong, due to strong binding of PEG segments to specific protein sites as it occurs for PEG antibodies, which can involve the terminal adsorption of free chain ends or backbone adsorption due to binding to interior chain segments. Ternary adsorption affects the capacity of brushes to repress protein adsorption. The strong adsorption of antibodies can trigger an immune response that may affect the biocompatibility of the surface. Theoretical adsorption isotherms and protein concentration profiles of the three cases are compared for "parabolic" brushes, allowing for the grafting density, 1/Sigma, and degree of polymerization of the PEG chains, N, as well as the volume and surface area of the proteins. The amount of adsorbed protein per unit area, Gamma, exhibits a mode-specific maximum in all three cases. For backbone and weak adsorption, Gamma approximately N, whereas for terminal adsorption, Gamma approximately N0. In every case, the concentration profile of adsorbed proteins, ctern(z), exhibits a maximum at zmax>0 that shifts outward as Sigma decreases; zmax=0 occurs only for weak and backbone adsorption at a high Sigma value.
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Affiliation(s)
- A Halperin
- Laboratoire de Spectrométrie Physique, Université Joseph Fourier-CNRS, UMR 5588, BP 87, 38402 Saint Martin d'Hères, France.
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