51
|
Li D, Wei Q, Wu C, Zhang X, Xue Q, Zheng T, Cao M. Superhydrophilicity and strong salt-affinity: Zwitterionic polymer grafted surfaces with significant potentials particularly in biological systems. Adv Colloid Interface Sci 2020; 278:102141. [PMID: 32213350 DOI: 10.1016/j.cis.2020.102141] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 12/21/2022]
Abstract
In recent years, zwitterionic polymers have been frequently reported to modify various surfaces to enhance hydrophilicity, antifouling and antibacterial properties, which show significant potentials particularly in biological systems. This review focuses on the fabrication, properties and various applications of zwitterionic polymer grafted surfaces. The "graft-from" and "graft-to" strategies, surface grafting copolymerization and post zwitterionization methods were adopted to graft lots type of the zwitterionic polymers on different inorganic/organic surfaces. The inherent hydrophilicity and salt affinity of the zwitterionic polymers endow the modified surfaces with antifouling, antibacterial and lubricating properties, thus the obtained zwitterionic surfaces show potential applications in biosystems. The zwitterionic polymer grafted membranes or stationary phases can effectively separate plasma, water/oil, ions, biomolecules and polar substrates. The nanomedicines with zwitterionic polymer shells have "stealth" effect in the delivery of encapsulated drugs, siRNA or therapeutic proteins. Moreover, the zwitterionic surfaces can be utilized as wound dressing, self-healing or oil extraction materials. The zwitterionic surfaces are expected as excellent support materials for biosensors, they are facing the severe challenges in the surface protection of marine facilities, and the dense ion pair layers may take unexpected role in shielding the grafted surfaces from strong electromagnetic field.
Collapse
|
52
|
Czeslik C, Wittemann A. Adsorption mechanism, secondary structure and local distribution of proteins at polyelectrolyte brushes. Colloid Polym Sci 2020. [DOI: 10.1007/s00396-019-04590-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
53
|
Zhang K, Yeung MCL, Leung SYL, Yam VWW. Platinum(II) Probes for Sensing Polyelectrolyte Lengths and Architectures. ACS APPLIED MATERIALS & INTERFACES 2020; 12:8503-8512. [PMID: 32027479 DOI: 10.1021/acsami.9b17611] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Platinum(II) polypyridine complexes of a square-planar geometry have been used as spectroscopic reporters for quantification of various charged species through non-covalent metal-metal interactions. The characterization of molecular weights and architectures of polyelectrolytes represents a challenging task in polymer science. Here, we report the utilization of platinum(II) complex probes and non-covalent metal-metal interactions for sensing polyelectrolyte lengths and architectures. It is found that the platinum(II) probes can bind to linear polyelectrolytes via electrostatic attractions and give rise to significant spectroscopic changes associated with the formation of metal-metal interactions, and the extent of the spectroscopic changes is found to increase with the lengths of the linear polyelectrolytes. Besides, the platinum(II) probes have been found to co-assemble with the linear polyelectrolytes to form well-defined nanofibers, and the lengths of the linear polyelectrolytes can be directly estimated from the diameter of the nanofibers under transmission electron microscopy observation. Interestingly, upon mixing with the platinum(II) probes, polyelectrolytes with bottlebrush architectures have been found to exhibit larger spectroscopic changes than linear polyelectrolytes with the same chemical composition. Combined with the reported theoretical studies on counterion condensation of polyelectrolytes, the platinum(II) complexes are found to function as spectroscopic probes for sensing the charge densities of the polyelectrolytes with different lengths and diverse architectures. Moreover, platinum(II) probes pre-organized in nanostructured aggregates have been found to intercalate into double-stranded DNA, which are naturally occurring biological polyelectrolytes with helical architectures and intercalation sites, to give significant enhancement of spectroscopic changes when compared to the intercalation of monomeric platinum(II) probes into double-stranded DNA.
Collapse
Affiliation(s)
- Kaka Zhang
- Institute of Molecular Functional Materials and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Margaret Ching-Lam Yeung
- Institute of Molecular Functional Materials and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Sammual Yu-Lut Leung
- Institute of Molecular Functional Materials and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Vivian Wing-Wah Yam
- Institute of Molecular Functional Materials and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| |
Collapse
|
54
|
Kavand A, Blanck C, Przybilla F, Mély Y, Anton N, Vandamme T, Serra CA, Chan-Seng D. Investigating the growth of hyperbranched polymers by self-condensing vinyl RAFT copolymerization from the surface of upconversion nanoparticles. Polym Chem 2020. [DOI: 10.1039/d0py00452a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The growth of hyperbranched polymers by self-condensing vinyl polymerization under RAFT conditions from the surface of upconversion nanoparticles is hindered by steric hinderance, but also increased termination and transfer reactions.
Collapse
Affiliation(s)
- Alireza Kavand
- Université de Strasbourg
- CNRS
- Institut Charles Sadron UPR 22
- F-67000 Strasbourg
- France
| | - Christian Blanck
- Université de Strasbourg
- CNRS
- Institut Charles Sadron UPR 22
- F-67000 Strasbourg
- France
| | - Frédéric Przybilla
- Université de Strasbourg
- CNRS
- Laboratoire de bioimagerie et pathologies UMR 7021
- F-67000 Strasbourg
- France
| | - Yves Mély
- Université de Strasbourg
- CNRS
- Laboratoire de bioimagerie et pathologies UMR 7021
- F-67000 Strasbourg
- France
| | - Nicolas Anton
- Université de Strasbourg
- CNRS
- Laboratoire de conception et application de molécules bioactives UMR 7199
- F-67000 Strasbourg
- France
| | - Thierry Vandamme
- Université de Strasbourg
- CNRS
- Laboratoire de conception et application de molécules bioactives UMR 7199
- F-67000 Strasbourg
- France
| | - Christophe A. Serra
- Université de Strasbourg
- CNRS
- Institut Charles Sadron UPR 22
- F-67000 Strasbourg
- France
| | - Delphine Chan-Seng
- Université de Strasbourg
- CNRS
- Institut Charles Sadron UPR 22
- F-67000 Strasbourg
- France
| |
Collapse
|
55
|
Ashrafizadeh SN, Seifollahi Z, Ganjizade A, Sadeghi A. Electrophoresis of spherical soft particles in electrolyte solutions: A review. Electrophoresis 2019; 41:81-103. [DOI: 10.1002/elps.201900236] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 11/11/2019] [Accepted: 11/11/2019] [Indexed: 02/01/2023]
Affiliation(s)
- Seyed Nezameddin Ashrafizadeh
- Research Lab for Advanced Separation ProcessesDepartment of Chemical EngineeringIran University of Science and Technology Tehran Iran
| | - Zahra Seifollahi
- Research Lab for Advanced Separation ProcessesDepartment of Chemical EngineeringIran University of Science and Technology Tehran Iran
| | - Ardalan Ganjizade
- Research Lab for Advanced Separation ProcessesDepartment of Chemical EngineeringIran University of Science and Technology Tehran Iran
| | - Arman Sadeghi
- Department of Mechanical EngineeringUniversity of Kurdistan Sanandaj Iran
| |
Collapse
|
56
|
The effects of grafting density and charge fraction on the properties of ring polyelectrolyte brushes: a molecular dynamics simulation study. Colloid Polym Sci 2019. [DOI: 10.1007/s00396-019-04579-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
57
|
Posel Z, Posocco P. Tuning the Properties of Nanogel Surfaces by Grafting Charged Alkylamine Brushes. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 9:E1514. [PMID: 31652985 PMCID: PMC6915512 DOI: 10.3390/nano9111514] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/17/2019] [Accepted: 10/21/2019] [Indexed: 12/13/2022]
Abstract
Nanogels are chemically crosslinked polymeric nanoparticles endowed with high encapsulation ability, tunable size, ease of preparation, and responsiveness to external stimuli. The presence of specific functional groups on their surfaces provides an opportunity to tune their surface properties and direct their behavior. In this work, we used mesoscale modeling to describe conformational and mechanical properties of nanogel surfaces formed by crosslinked polyethylene glycol and polyethyleneimine, and grafted by charged alkylamine brushes of different lengths. Simulations show that both number of chains per area and chain length can be used to tune the properties of the coating. Properly selecting these two parameters allows switching from a hydrated, responsive coating to a dried, highly charged layer. The results also suggest that the scaling behavior of alkylamine brushes, e.g., the transition from a mushroom to semi-dilute brush, is only weakly coupled with the shielding ability of the coating and much more with its compressibility.
Collapse
Affiliation(s)
- Zbyšek Posel
- Department of Informatics, Faculty of Science, Jan Evangelista Purkyně University in Ústí nad Labem, 40096 Ústí nad Labem, Czech Republic.
- Department of Engineering and Architecture, University of Trieste, 34127 Trieste, Italy.
| | - Paola Posocco
- Department of Engineering and Architecture, University of Trieste, 34127 Trieste, Italy.
| |
Collapse
|
58
|
Hollingsworth NR, Wilkanowicz SI, Larson RG. Salt- and pH-induced swelling of a poly(acrylic acid) brush via quartz crystal microbalance w/dissipation (QCM-D). SOFT MATTER 2019; 15:7838-7851. [PMID: 31528970 DOI: 10.1039/c9sm01289c] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We infer the swelling/de-swelling behavior of weakly ionizable poly(acrylic acid) (PAA) brushes of 2-39 kDa molar mass in the presence of KCl concentrations from 0.1-1000 mM, pH = 3, 7, and 9, and grafting densities σ = 0.12-2.15 chains per nm2 using a Quartz Crystal Microbalance with Dissipation (QCM-D), confirming and extending the work of Wu et al. to multiple chain lengths. At pH 7 and 9 (above the pKa ∼ 5), the brush initially swells at low KCl ionic strength (<10 mM) in the "osmotic brush" regime, and de-swells at higher salt concentrations, in the "salted brush" regime, and is relatively unaffected at pH 3, below the pKa, as expected. At pH 7, at low and moderate grafting densities, our results in the high-salt "salted brush" regime (Cs > 10 mM salt) agree with the predicted scaling H ∼ Nσ+1/3Cs-1/3 of brush height H, while in the low-salt "osmotic brush" regime (Cs < 10 mM salt), we find H ∼ Nσ+1/3Cs+0.28-0.38, whose dependence on Cs agrees with scaling theory for this regime, but the dependence on σ strongly disagrees with it. The predicted linearity in the degree of polymerization N is confirmed. The new results partially confirm scaling theory and clarify where improved theories and additional data are needed.
Collapse
Affiliation(s)
- Nisha R Hollingsworth
- Department of Macromolecular Science & Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
| | | | | |
Collapse
|
59
|
Hydrodynamic Properties of Polymers Screening the Electrokinetic Flow: Insights from a Computational Study. Polymers (Basel) 2019; 11:polym11061038. [PMID: 31212690 PMCID: PMC6631430 DOI: 10.3390/polym11061038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 01/29/2023] Open
Abstract
Understanding the hydrodynamic properties of polymeric coatings is crucial for the rational design of molecular transport involving polymeric surfaces and is relevant to drug delivery, sieving, molecular separations, etc. It has been found that the hydrodynamic radius of a polymer segment is an order of magnitude smaller than its physical size, but the origin of this effect does not seem to be well understood. Herein, we study the hydrodynamic properties of polymeric coatings by using molecular dynamics simulations, navigated by the continuous Navier-Stokes-Brinkman model. We confirm that the averaged hydrodynamic radius of a polymer bead is about one order of magnitude smaller than its physical radius, and, in addition, we show that it exhibits a strong dependence on the degree of polymerization. We relate this variation of the hydrodynamic radius to the structural properties and hydrodynamic shielding by surrounding polymer beads. This is done by separating the effects originating from near and far beads. For the near beads, shielding is mainly due to the two nearest beads (of the same polymer) and leads to about a 5-fold reduction in the hydrodynamic radius. Assuming the additivity of the hydrodynamic shielding by far beads, we suggest a simple model, which captures correctly the qualitative behaviour of the hydrodynamic radius with the degree of polymerization. The revealed shielding effects provide important insights relevant to the advanced modelling of hydrodynamic properties of polymeric coatings.
Collapse
|
60
|
Levin A, Cinar S, Paulus M, Nase J, Winter R, Czeslik C. Analyzing protein-ligand and protein-interface interactions using high pressure. Biophys Chem 2019; 252:106194. [PMID: 31177023 DOI: 10.1016/j.bpc.2019.106194] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 01/06/2023]
Abstract
All protein function is based on interactions with the environment. Proteins can bind molecules for their transport, their catalytic conversion, or for signal transduction. They can bind to each other, and they adsorb at interfaces, such as lipid membranes or material surfaces. An experimental characterization is needed to understand the underlying mechanisms, but also to make use of proteins in biotechnology or biomedicine. When protein interactions are studied under high pressure, volume changes are revealed that directly describe spatial contributions to these interactions. Moreover, the strength of protein interactions with ligands or interfaces can be tuned in a smooth way by pressure modulation, which can be utilized in the design of drugs and bio-responsive interfaces. In this short review, selected studies of protein-ligand and protein-interface interactions are presented that were carried out under high pressure. Furthermore, a perspective on bio-responsive interfaces is given where protein-ligand binding is applied to create functional interfacial structures.
Collapse
Affiliation(s)
- Artem Levin
- Technische Universität Dortmund, Fakultät für Chemie und Chemische Biologie, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
| | - Süleyman Cinar
- Technische Universität Dortmund, Fakultät für Chemie und Chemische Biologie, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
| | - Michael Paulus
- Technische Universität Dortmund, Fakultät Physik/Delta, D-44221 Dortmund, Germany
| | - Julia Nase
- Technische Universität Dortmund, Fakultät Physik/Delta, D-44221 Dortmund, Germany
| | - Roland Winter
- Technische Universität Dortmund, Fakultät für Chemie und Chemische Biologie, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
| | - Claus Czeslik
- Technische Universität Dortmund, Fakultät für Chemie und Chemische Biologie, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany.
| |
Collapse
|
61
|
Santos DES, Li D, Ramstedt M, Gautrot JE, Soares TA. Conformational Dynamics and Responsiveness of Weak and Strong Polyelectrolyte Brushes: Atomistic Simulations of Poly(dimethyl aminoethyl methacrylate) and Poly(2-(methacryloyloxy)ethyl trimethylammonium chloride). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:5037-5049. [PMID: 30869897 DOI: 10.1021/acs.langmuir.8b04268] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The complex solution behavior of polymer brushes is key to control their properties, including for biomedical applications and catalysis. The swelling behavior of poly(dimethyl aminoethyl methacrylate) (PDMAEMA) and poly(2-(methacryloyloxy)ethyl trimethylammonium chloride) (PMETAC) in response to changes in pH, solvent, and salt types has been investigated using atomistic molecular dynamics simulations. PDMAEMA and PMETAC have been selected as canonical models for weak and strong polyelectrolytes whose complex conformational behavior is particularly challenging for the development and validation of atomistic models. The GROMOS-derived atomic parameters reproduce the experimental swelling coefficients obtained from ellipsometry measurements for brushes of 5-15 nm thickness. The present atomistic models capture the protonated morphology of PDMAEMA, the swollen and collapsed conformations of PDMAEMA and PMETAC in good and bad solvents, and the salt-selective response of PMETAC. The modular nature of the molecular models allows for the simple extension of atomic parameters to a variety of polymers or copolymers.
Collapse
Affiliation(s)
- Denys E S Santos
- Departamento de Química Fundamental , Universidade Federal de Pernambuco , Cidade Universitária, 50670-901 Recife , Brazil
| | | | | | | | - Thereza A Soares
- Departamento de Química Fundamental , Universidade Federal de Pernambuco , Cidade Universitária, 50670-901 Recife , Brazil
- Department of Chemistry , Umeå University , 90187 Umeå , Sweden
| |
Collapse
|
62
|
Gorthi SR, Gaikwad HS, Mondal PK, Biswas G. Surface Tension Driven Filling in a Soft Microchannel: Role of Streaming Potential. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b00767] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Srinivas R. Gorthi
- Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Assam, India 781039
| | - Harshad Sanjay Gaikwad
- Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Assam, India 781039
| | - Pranab Kumar Mondal
- Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Assam, India 781039
| | - Gautam Biswas
- Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Assam, India 781039
| |
Collapse
|
63
|
Zhang F, Wang S, Ding H, Tong C. Simulations of 3-arm polyelectrolyte star brushes under external electric fields. SOFT MATTER 2019; 15:2560-2570. [PMID: 30698599 DOI: 10.1039/c8sm02131g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Langevin dynamics (LD) simulations have been performed to study the conformations and stratification of grafted three-arm polyelectrolyte (PE) stars in response to external electric fields. The grafted chains with neutral stems and fully charged branches were immersed in a salt-free solution sandwiched between the grafting electrode and a second oppositely charged electrode. The branching points of neutral-stem PE brushes at low grafting densities exhibit a bimodal distribution normal to the grafting electrode. With increasing grafting density, the molecular conformations in the brush layer become more complex with the emergence of multi-mode distributions of the branching point monomers. Under strong electric fields, the fraction of grafted chains with either nearly completely stretched stems or collapsed branches onto the grafting electrode gradually decreases with increasing grafting density due to the stronger electrostatic screening from counterions and monomer charges at higher grafting densities. Simulation results revealed that a collapsing electric field promotes the stratification within the brush layer, leading to high degrees of charge overcompensation from charged monomers collapsed onto the oppositely charged grafting electrode. An approximate analytical self-consistent field model was developed to examine the stratification within the brush layer. Regarding the fraction of grafted chains with the free branches in the upper layer, the prediction of the analytical model qualitatively agrees with the simulation results.
Collapse
Affiliation(s)
- Fen Zhang
- Department of Physics, Ningbo University, Ningbo, Zhejiang, 315211, China.
| | | | | | | |
Collapse
|
64
|
Liu G. Tuning the Properties of Charged Polymers at the Solid/Liquid Interface with Ions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3232-3247. [PMID: 29806944 DOI: 10.1021/acs.langmuir.8b01158] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In conventional theories, where ions are treated as point charges, the properties of charged polymers can be tuned using ions via the ionic strength. However, this article will show that the properties of charged polymers at the solid/liquid interface, including charged polymer brushes and polyelectrolyte multilayers, can be tuned by ions beyond ionic strength effects. Ion specificity, multivalency, ionic hydrogen bonding, and ionic hydrophobicity/hydrophilicity are used to tune a range of properties of charged polymers at the solid/liquid interface such as hydration, conformation, stiffness, surface wettability, lubricity, adhesion, and protein adsorption. The ionic effects demonstrated here greatly broaden our understanding of the use of ions to tune the interfacial properties of charged polymers. It is anticipated that these ionic effects can be further expanded by incorporating new types of important ion-charged polymer interactions and can also be extended to neutral polymer systems.
Collapse
Affiliation(s)
- Guangming Liu
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics , University of Science and Technology of China , Hefei , P. R. China 230026
| |
Collapse
|
65
|
Ferrand-Drake Del Castillo G, Koenig M, Müller M, Eichhorn KJ, Stamm M, Uhlmann P, Dahlin A. Enzyme Immobilization in Polyelectrolyte Brushes: High Loading and Enhanced Activity Compared to Monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3479-3489. [PMID: 30742441 DOI: 10.1021/acs.langmuir.9b00056] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Catalysis by enzymes on surfaces has many applications. However, strategies for efficient enzyme immobilization with preserved activity are still in need of further development. In this work, we investigate polyelectrolyte brushes prepared by both grafting-to and grafting-from with the aim to achieve high catalytic activity. For comparison, self-assembled monolayers that bind enzymes with the same chemical interactions are included. We use the model enzyme glucose oxidase and two kinds of polymers: anionic poly(acrylic acid) and cationic poly(diethylamino)methyl methacrylate. Surface plasmon resonance and spectroscopic ellipsometry are used for accurate quantification of surface coverage. Besides binding more enzymes, the "3D-like" brush environment enhances the specific activity compared to immobilization on self-assembled monolayers. For grafting-from brushes, multilayers of enzymes were spontaneously and irreversibly immobilized without conjugation chemistry. When the pH was between the pI of the enzyme and the p Ka of the polymer, binding was considerable (thousands of ng/cm2 or up to 50% of the polymer mass), even at physiological ionic strength. However, binding was observed also when the brushes were neutrally charged. For acidic brushes (both grafting-to and grafting-from), the activity was higher for covalent immobilization compared to noncovalent. For grafting-from brushes, a fully preserved specific activity compared to enzymes in the liquid bulk was achieved, both with covalent (acidic brush) and noncovalent (basic brush) immobilization. Catalytic activity of hundreds of pmol cm-2 s-1 was easily obtained for polybasic brushes only tens of nanometers in dry thickness. This study provides new insights for designing functional interfaces based on enzymatic catalysis.
Collapse
Affiliation(s)
| | - Meike Koenig
- Leibniz Institute of Polymer Research Dresden , Hohe Str. 6 , D-01069 Dresden , Germany
| | - Martin Müller
- Leibniz Institute of Polymer Research Dresden , Hohe Str. 6 , D-01069 Dresden , Germany
- Technische Universität Dresden, Physical Chemistry of Polymer Materials, Dresden , Germany
| | - Klaus-Jochen Eichhorn
- Leibniz Institute of Polymer Research Dresden , Hohe Str. 6 , D-01069 Dresden , Germany
| | - Manfred Stamm
- Leibniz Institute of Polymer Research Dresden , Hohe Str. 6 , D-01069 Dresden , Germany
- Technische Universität Dresden, Physical Chemistry of Polymer Materials, Dresden , Germany
| | - Petra Uhlmann
- Leibniz Institute of Polymer Research Dresden , Hohe Str. 6 , D-01069 Dresden , Germany
- Department of Chemistry , University of Nebraska-Lincoln , Hamilton Hall, 639 North 12th Street , Lincoln , Nebraska 68588 , United States
| | - Andreas Dahlin
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , 41296 Göteborg , Sweden
| |
Collapse
|
66
|
Emamyari S, Fazli H. Single-Chain Conformational Characteristics of Comb-Like Polyelectrolytes: Molecular Dynamics Simulation Study. Macromol Res 2018. [DOI: 10.1007/s13233-019-7010-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
67
|
Elizarova IS, Luckham PF. Layer-by-layer adsorption: Factors affecting the choice of substrates and polymers. Adv Colloid Interface Sci 2018; 262:1-20. [PMID: 30448237 DOI: 10.1016/j.cis.2018.11.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 11/04/2018] [Accepted: 11/06/2018] [Indexed: 01/10/2023]
Abstract
The electrostatic layer-by-layer technique for fabrication of multi-layered structures of various sizes and shapes using flat and colloidal templates coupled with polyelectrolyte layer-forming materials has attracted significant interest among both academic and industrial researchers due to its versatility and relative simplicity of the procedures involved in its execution. Fabrication of the multi-layered structures using the electrostatic layer-by-layer method involves several distinct stages each of which holds great importance when considering the production of a high-quality product. These stages include selection of materials (both template and a pair of construction polyelectrolytes), adsorption of the first polyelectrolyte layer onto the selected templates, formation of the second layer comprised of the oppositely charged polyelectrolyte and guided by the interactions between the two chosen polyelectrolytes, and multi-layering, where a selected number of layers are produced, and which is conditioned by both intrinsic properties of the involved construction materials and external fabrication conditions such as temperature, pH and ionic strength. The current review summarises the most important aspects of each stage mentioned above and gives examples of the materials suitable for utilization of the technique and describes the underlying physics involved.
Collapse
|
68
|
Hao QH, Xia G, Tan HG, Chen EQ, Yang S. Surface morphologies of spherical polyelectrolyte brushes induced by trivalent salt ions. Phys Chem Chem Phys 2018; 20:26542-26551. [PMID: 30306970 DOI: 10.1039/c8cp04235g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The surface morphologies of spherical polyelectrolyte brushes in salt solutions with opposite trivalent ions are studied using molecular dynamics (MD) simulations. The impact of salt concentration, grafting density, and charge fraction on brush morphologies is investigated systematically. A variety of surface patterns are predicted and the phase diagrams are presented. Both lateral and radial microphase separated structures in the brushes are observed upon varying the salt concentration. With low grafting density the spherical brush is separated into several patches, the number of which decreases with the addition of salt. At high grafting density, the polymer brush changes its morphology from an extended micelle to a 'carpet + brush' to the collapsed state upon increasing the salt concentration. Especially, the 'carpet + brush' structure consists of a core formed by partially collapsed brush chains and a corona formed by other stretched chains. The inter-chain 'bridging' interactions mediated by trivalent ions and the curvature effect play important roles in determining the chain conformations and brush structures.
Collapse
Affiliation(s)
- Qing-Hai Hao
- College of Science, Civil Aviation University of China, Tianjin 300300, China
| | - Gang Xia
- College of Science, Civil Aviation University of China, Tianjin 300300, China
| | - Hong-Ge Tan
- College of Science, Civil Aviation University of China, Tianjin 300300, China
| | - Er-Qiang Chen
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Shuang Yang
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| |
Collapse
|
69
|
The role of ion partitioning in electrohydrodynamic characteristics of soft nanofluidics: Inclusion of EDL overlap and steric effects. Chem Eng Sci 2018. [DOI: 10.1016/j.ces.2018.05.049] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
|
70
|
Desai PR, Das S. Lubrication in polymer-brush bilayers in the weak interpenetration regime: Molecular dynamics simulations and scaling theories. Phys Rev E 2018; 98:022503. [PMID: 30253630 DOI: 10.1103/physreve.98.022503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Indexed: 11/06/2022]
Abstract
We conduct molecular dynamics (MD) simulations and develop scaling laws to quantify the lubrication behavior of weakly interpenetrated polymer brush bilayers in the presence of an external shear force. The weakly interpenetrated regime is characterized by 1<d_{g}/d_{0}<2, where d_{g} is the gap between the opposing surfaces (where the brushes are grafted) and d_{0} is the unperturbed brush height. MD simulations predict that in the shear thinning regime, characterized by a larger shear force or a large Weissenberg number (W), R_{g}^{2}∼W^{0.19} and η∼W^{-0.38}, where R_{g} is the chain extension in the direction of the shear and η is the viscosity. These scaling behaviors, which are distinctly different from that witnessed in strongly compressed regime (for such a regime, characterized by d_{g}/d_{0}<1, R_{g}^{2}∼W^{0.53}, and η∼W^{-0.46}), match excellently with those predicted by our scaling theory.
Collapse
Affiliation(s)
- Parth Rakesh Desai
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Siddhartha Das
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, USA
| |
Collapse
|
71
|
Chen G, Sachar HS, Das S. Efficient electrochemomechanical energy conversion in nanochannels grafted with end-charged polyelectrolyte brushes at medium and high salt concentration. SOFT MATTER 2018; 14:5246-5255. [PMID: 29888349 DOI: 10.1039/c8sm00768c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We develop a theory to study the generation of the streaming potential and the resulting electrochemomechanical energy conversion (ECMEC) in the presence of pressure-driven transport in nanochannels grafted with end-charged polyelectrolyte (PE) brushes. Our theory gives a thermodynamically self-consistent coupled description of the PE-brush and the electrostatics of the electric double layer (EDL) induced by the PE charges. The end-charged brushes localize the maximum EDL charge density away from the wall, thereby enabling a larger magnitude of pressure-driven transport to stream the ions downstream. This effect is retarded by the drag force imparted by the brushes as well as by the enhanced electroosmotic transport in a direction opposite to the pressure-driven transport. An interplay of these three issues leads to highly non-trivial electrohydrodynamic transport that eventually allows us to converge on appropriate properties of the brushes (e.g., grafting density and the number of monomers) that lead to the generation of a significantly larger streaming potential and a much improved efficiency of the ECMEC as compared to the brush-free nanochannels particularly at medium and high salt concentrations.
Collapse
Affiliation(s)
- Guang Chen
- Department of Mechanical Engineering, University of Maryland, College Park, MD-20742, USA.
| | | | | |
Collapse
|
72
|
|
73
|
Kou R, Zhang J, Chen Z, Liu G. Counterion Specificity of Polyelectrolyte Brushes: Role of Specific Ion-Pairing Interactions. Chemphyschem 2018; 19:1404-1413. [PMID: 29575481 DOI: 10.1002/cphc.201701256] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Indexed: 11/10/2022]
Abstract
We demonstrate here that the properties of poly (2-(methacryloyloxy) ethyl trimethylammonium chloride) brushes can be tuned by counterion species. When the brushes are exposed to external chloride (Cl- ) counterions, obvious dehydration and collapse are only observed at high salt concentrations. In the presence of very strongly chaotropic perchlorate (ClO4- ), the brushes strongly dehydrate and collapse at a very low salt concentration. For the strongly chaotropic thiocyanate ion (SCN- ), the changes in hydration and conformation of the brushes are similar to those observed for ClO4- but at a smaller extent at very low salt concentrations. With the addition of kosmotropic acetate (Ac- ), hydration of the brushes increases, accompanied by a swelling of the brushes in the low-salt-concentration regime. In contrast, the brushes dehydrate and collapse with increasing concentration of Ac- in the high-salt-concentration regime. The counterion specificity of the brushes demonstrated here is determined by specific ion-pairing interactions through modulating the osmotic pressure within the brushes and the hydrophobicity of the ion pairs.
Collapse
Affiliation(s)
- Ran Kou
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Jian Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Zhen Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Guangming Liu
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, P. R. China
| |
Collapse
|
74
|
Brownian Dynamics Simulations of Rigid Polyelectrolyte Chains Grafting to Spherical Colloid. CHINESE JOURNAL OF POLYMER SCIENCE 2018. [DOI: 10.1007/s10118-018-2042-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
75
|
Kajihara M, Aoki D, Matsushita Y, Fukushima K. Synthesis and characterization of lignin-based cationic dye-flocculant. J Appl Polym Sci 2018. [DOI: 10.1002/app.46611] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Masaru Kajihara
- Graduate School of Bioagricultural Sciences; Nagoya University; Chikusa-ku Nagoya 464-8601 Japan
| | - Dan Aoki
- Graduate School of Bioagricultural Sciences; Nagoya University; Chikusa-ku Nagoya 464-8601 Japan
| | - Yasuyuki Matsushita
- Graduate School of Bioagricultural Sciences; Nagoya University; Chikusa-ku Nagoya 464-8601 Japan
| | - Kazuhiko Fukushima
- Graduate School of Bioagricultural Sciences; Nagoya University; Chikusa-ku Nagoya 464-8601 Japan
| |
Collapse
|
76
|
Xiao S, Ren B, Huang L, Shen M, Zhang Y, Zhong M, Yang J, Zheng J. Salt-responsive zwitterionic polymer brushes with anti-polyelectrolyte property. Curr Opin Chem Eng 2018. [DOI: 10.1016/j.coche.2017.12.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
77
|
Desai PR, Sinha S, Das S. Polyelectrolyte brush bilayers in weak interpenetration regime: Scaling theory and molecular dynamics simulations. Phys Rev E 2018; 97:032503. [PMID: 29776032 DOI: 10.1103/physreve.97.032503] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Indexed: 06/08/2023]
Abstract
We employ molecular dynamics (MD) simulations and develop scaling theories to quantify the equilibrium behavior of polyelectrolyte (PE) brush bilayers (BBLs) in the weakly interpenetrated regime, which is characterized by d_{0}<d_{g}<2d_{0}, where d_{g} is the gap between the opposing plates where the PE brushes are grafted and d_{0} is the unperturbed height of a PE brush grafted at a single plate. Scaling predictions establish that, for the weakly interpenetrated osmotic PE BBLs δ∼N^{1/2}(2-d_{g}/d_{0})^{1/2} (where δ is the interpenetration length and N is the number of Kuhn segments in PE brush). MD simulations excellently recover this dependence of δ on N and the extent of interpenetration (quantified by d_{g}/d_{0}). These predictions, unlike the existing studies, establish a finite interpenetration for all values of d_{g}/d_{0} as long as d_{g}<2d_{0}. Finally, we quantify the monomer and counterion concentration distributions and point out that these two distributions may quantitatively deviate from each other at locations very close to the channel centerline, where the interpenetration-induced monomer concentration can be significantly low.
Collapse
Affiliation(s)
- Parth Rakesh Desai
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Shayandev Sinha
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Siddhartha Das
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, USA
| |
Collapse
|
78
|
|
79
|
Wu W, Dai W, Zhao X, Zhang J, Zhao Y. Synthesis, self-assembly and drug release behaviors of reduction-labile multi-responsive block miktobrush quaterpolymers with linear and V-shaped grafts. Polym Chem 2018. [DOI: 10.1039/c8py00245b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Stimuli-tunable topological/morphological transitions and drug release properties based on novel disulfide-functionalized coil–comb–coil quaterpolymers were revealed.
Collapse
Affiliation(s)
- Wentao Wu
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- College of Chemistry
- Chemical Engineering and Materials Science
| | - Wenxue Dai
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- College of Chemistry
- Chemical Engineering and Materials Science
| | - Xiaoqi Zhao
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- College of Chemistry
- Chemical Engineering and Materials Science
| | - Jian Zhang
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- College of Chemistry
- Chemical Engineering and Materials Science
| | - Youliang Zhao
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- College of Chemistry
- Chemical Engineering and Materials Science
| |
Collapse
|
80
|
Shang X, Kröger M, Leimkuhler B. Assessing numerical methods for molecular and particle simulation. SOFT MATTER 2017; 13:8565-8578. [PMID: 29099134 DOI: 10.1039/c7sm01526g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We discuss the design of state-of-the-art numerical methods for molecular dynamics, focusing on the demands of soft matter simulation, where the purposes include sampling and dynamics calculations both in and out of equilibrium. We discuss the characteristics of different algorithms, including their essential conservation properties, the convergence of averages, and the accuracy of numerical discretizations. Formulations of the equations of motion which are suited to both equilibrium and nonequilibrium simulation include Langevin dynamics, dissipative particle dynamics (DPD), and the more recently proposed "pairwise adaptive Langevin" (PAdL) method, which, like DPD but unlike Langevin dynamics, conserves momentum and better matches the relaxation rate of orientational degrees of freedom. PAdL is easy to code and suitable for a variety of problems in nonequilibrium soft matter modeling; our simulations of polymer melts indicate that this method can also provide dramatic improvements in computational efficiency. Moreover we show that PAdL gives excellent control of the relaxation rate to equilibrium. In the nonequilibrium setting, we further demonstrate that while PAdL allows the recovery of accurate shear viscosities at higher shear rates than are possible using the DPD method at identical timestep, it also outperforms Langevin dynamics in terms of stability and accuracy at higher shear rates.
Collapse
Affiliation(s)
- Xiaocheng Shang
- Department of Materials, Polymer Physics, ETH Zürich, CH-8093 Zürich, Switzerland.
| | | | | |
Collapse
|
81
|
Speyer K, Pastorino C. Droplet Transport in a Nanochannel Coated by Hydrophobic Semiflexible Polymer Brushes: The Effect of Chain Stiffness. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:10753-10763. [PMID: 28892398 DOI: 10.1021/acs.langmuir.7b02640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We study the influence of chain stiffness on droplet flow in a nanochannel, coated with semiflexible hydrophobic polymers by means of nonequilibrium molecular dynamics simulations. The studied system is then a moving droplet in the slit channel, coexisting with its vapor and subjected to periodic boundary conditions in the flow direction. The polymer chains, grafted by the terminal bead to the confining walls, are described by a coarse-grained model that accounts for chain connectivity, excluded volume interactions and local chain stiffness. The rheological, frictional and dynamical properties of the brush are explored over a wide range of persistence lengths. We find a rich behavior of polymer conformations and concomitant changes in the friction properties over the wide range of studied polymer stiffnesses. A rapid decrease in the droplet velocity was observed as the rigidity of the chains is increased for polymers whose persistence length is smaller than their contour length. We find a strong relation between the internal dynamics of the brush and the droplet transport properties, which could be used to tailor flow properties by surface functionalization. The monomers of the brush layer, under the droplet, present a collective "treadmill belt" like dynamics which can only be present due the existence of grafted chains. We describe its changes in spatial extension upon variations of polymer stiffness, with bidimensional velocity and density profiles. The deformation of the polymer brushes due to the presence of the droplet is analyzed in detail. Lastly, the droplet-gas interaction is studied by varying the liquid to gas ratio, observing a 16% speed increase for droplets that flow close to each other, compared to a train of droplets that present a large gap between consecutive droplets.
Collapse
Affiliation(s)
- K Speyer
- Departamento de Física de la Materia Condensada, Centro Atómico Constituyentes, CNEA , Av.Gral. Paz 1499, 1650 Pcia. de Buenos Aires, Argentina
- CONICET , Godoy Cruz 2290 (C1425FQB) Buenos Aires, Argentina
| | - C Pastorino
- Departamento de Física de la Materia Condensada, Centro Atómico Constituyentes, CNEA , Av.Gral. Paz 1499, 1650 Pcia. de Buenos Aires, Argentina
- CONICET , Godoy Cruz 2290 (C1425FQB) Buenos Aires, Argentina
| |
Collapse
|
82
|
Glova AD, Larin SV, Falkovich SG, Nazarychev VM, Tolmachev DA, Lukasheva NV, Lyulin SV. Molecular dynamics simulations of oligoester brushes: the origin of unusual conformations. SOFT MATTER 2017; 13:6627-6638. [PMID: 28926071 DOI: 10.1039/c7sm01419h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present results from all-atom molecular dynamics simulations for the structural properties of oligomeric lactic acid chains (OLA) grafted to the surface of cellulose nanocrystals (CNCs) and immersed in the melt of polylactic acid (PLA). Earlier, we have found that the distribution of free ends of OLA molecules is bimodal [Glova et al., Polym. Int., 2016, 65(8), 892]. The results cannot be explained within the standard picture of uncharged polymer brushes exposed to the melt of a chemically identical polymer. Although the oligomeric brushes of the OLA chains are uncharged, they have partial polarization charges producing a non-zero dipole moment of the monomeric chain unit. We study the influence of partial charges on the structure of the layer of OLA chains grafted to the CNC surface. A detailed analysis of the conformations of the grafted chains shows that interaction of partial charges in the models causes bending of the OLA molecules toward the cellulose surface, forming a hairpin structure. The observed separation of the grafted chains into two populations increases with grafting density. We demonstrate that hydrogen bonds can be formed between the free ends of the grafted chains and the CNC surface, but they do not affect the brush structure significantly. Thus, dipole-dipole interactions turn out to be the key factor governing the unusual conformations of grafts.
Collapse
Affiliation(s)
- A D Glova
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bolshoj pr. V.O., 31, 199004 Saint Petersburg, Russia.
| | | | | | | | | | | | | |
Collapse
|
83
|
Tergolina VB, dos Santos AP. Effect of dielectric discontinuity on a spherical polyelectrolyte brush. J Chem Phys 2017; 147:114103. [DOI: 10.1063/1.5002526] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- Vinicius B. Tergolina
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970 Porto Alegre, RS, Brazil
| | - Alexandre P. dos Santos
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970 Porto Alegre, RS, Brazil
- Fachbereich Physik, Freie Universität Berlin, 14195 Berlin, Germany
| |
Collapse
|
84
|
Nakamura S, Mitomo H, Aizawa M, Tani T, Matsuo Y, Niikura K, Pike A, Naya M, Shishido A, Ijiro K. DNA Brush-Directed Vertical Alignment of Extensive Gold Nanorod Arrays with Controlled Density. ACS OMEGA 2017; 2:2208-2213. [PMID: 31457571 PMCID: PMC6641014 DOI: 10.1021/acsomega.7b00303] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/10/2017] [Indexed: 05/07/2023]
Abstract
Control over the orientation of metal nanorods is important for both fundamental and applied research. We show that gold nanorods (GNRs) can be aligned in a single direction by adsorbing positively charged GNRs onto a double-strand DNA-grafted substrate through electrostatic interaction. The ordered structure can be optimized by controlling the density of the positive charges on the surface of the GNRs. We found, in agreement with the results of theoretical simulation, that the resultant structure exhibits plasmonic properties that are dependent on the GNR orientation relative to the direction of an oscillating electric field. Our approach provides new insights into the polymer-assisted self-assembly of rod-shaped nanoparticles utilizing electrostatic interactions.
Collapse
Affiliation(s)
- Satoshi Nakamura
- Graduate
School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Hideyuki Mitomo
- Research Institute for Electronic Science and Global Station for Soft Matter, Global
Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo 001-0021, Japan
| | - Miho Aizawa
- Laboratory
for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | | | - Yasutaka Matsuo
- Research Institute for Electronic Science and Global Station for Soft Matter, Global
Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo 001-0021, Japan
| | - Kenichi Niikura
- Research Institute for Electronic Science and Global Station for Soft Matter, Global
Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo 001-0021, Japan
| | - Andrew Pike
- School of
Chemistry, Newcastle University, Bedson Building, Newcastle upon Tyne NE1 7RU, U.K.
| | | | - Atsushi Shishido
- Laboratory
for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Kuniharu Ijiro
- Research Institute for Electronic Science and Global Station for Soft Matter, Global
Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo 001-0021, Japan
| |
Collapse
|
85
|
Chen WL, Cordero R, Tran H, Ober CK. 50th Anniversary Perspective: Polymer Brushes: Novel Surfaces for Future Materials. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00450] [Citation(s) in RCA: 296] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Wei-Liang Chen
- Department of Materials Science & Engineering, ‡Smith School of Chemical and Biomolecular Engineering, and §Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Roselynn Cordero
- Department of Materials Science & Engineering, ‡Smith School of Chemical and Biomolecular Engineering, and §Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Hai Tran
- Department of Materials Science & Engineering, ‡Smith School of Chemical and Biomolecular Engineering, and §Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Christopher K. Ober
- Department of Materials Science & Engineering, ‡Smith School of Chemical and Biomolecular Engineering, and §Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| |
Collapse
|
86
|
Chen G, Das S. Massively Enhanced Electroosmotic Transport in Nanochannels Grafted with End-Charged Polyelectrolyte Brushes. J Phys Chem B 2017; 121:3130-3141. [DOI: 10.1021/acs.jpcb.7b00493] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Guang Chen
- Department of Mechanical
Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Siddhartha Das
- Department of Mechanical
Engineering, University of Maryland, College Park, Maryland 20742, United States
| |
Collapse
|
87
|
Li F, Jian Y, Xie Z, Liu Y, Liu Q. Transient alternating current electroosmotic flow of a Jeffrey fluid through a polyelectrolyte-grafted nanochannel. RSC Adv 2017. [DOI: 10.1039/c6ra24930b] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Comparison of the velocity amplitude for Newtonian, Maxwell and Jeffrey fluids in PE-grafted and rigid nanochannels.
Collapse
Affiliation(s)
- Fengqin Li
- School of Mathematical Science
- Inner Mongolia University
- Hohhot
- PR China
| | - Yongjun Jian
- School of Mathematical Science
- Inner Mongolia University
- Hohhot
- PR China
| | - Zhiyong Xie
- School of Mathematical Science
- Inner Mongolia University
- Hohhot
- PR China
| | - Yongbo Liu
- School of Mathematical Science
- Inner Mongolia University
- Hohhot
- PR China
| | - Quansheng Liu
- School of Mathematical Science
- Inner Mongolia University
- Hohhot
- PR China
| |
Collapse
|
88
|
Bae JY, Lee HJ, Choi WS. Cube sugar-like sponge/polymer brush composites for portable and user-friendly heavy metal ion adsorbents. JOURNAL OF HAZARDOUS MATERIALS 2016; 320:133-142. [PMID: 27526279 DOI: 10.1016/j.jhazmat.2016.07.067] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 07/27/2016] [Accepted: 07/28/2016] [Indexed: 06/06/2023]
Abstract
Portable, non-toxic, and user-friendly sponge composites decorated with polyelectrolyte (PE) brushes were developed for the fast and efficient removal of heavy metal ions from waste water or drinking water. The polyacrylamide (PAM) and polyacrylic acid (PAA) brushes were grafted onto the sponge via "grafting-from" polymerization. For the polyethyleneimine (PEI) brush, "grafting-to" polymerization was used. A polydopamine (Pdop) layer was first coated on the sponge. Then, PEI was grafted onto the Pdop-coated sponge via a Michael addition reaction. The PEI-grafted sponge exhibited the best adsorption capacity and the fastest reaction rate of all the brushes due to the numerous adsorption sites of the PEI. The adsorption performance of two different PEI-grafted sponges depended on the molecular weight (MW) of the PEI. Simply by being dipped into a glass of water, non-toxic PEI-grafted sponge instantly removed the low concentration heavy metal ions, demonstrating a practical application for individual users.
Collapse
Affiliation(s)
- Ji Young Bae
- Department of Chemical and Biological Engineering, Hanbat National University, San 16-1, Dukmyoung dong, Yuseong-gu, Daejeon, 305-719, Republic of Korea
| | - Ha-Jin Lee
- Western Seoul Center, Korea Basic Science Institute, 150 Bugahyun-ro, Seoudaemun-gu, Seoul, 120-140, Republic of Korea.
| | - Won San Choi
- Department of Chemical and Biological Engineering, Hanbat National University, San 16-1, Dukmyoung dong, Yuseong-gu, Daejeon, 305-719, Republic of Korea.
| |
Collapse
|
89
|
Alternating current electroosmotic flow in polyelectrolyte-grafted nanochannel. Colloids Surf B Biointerfaces 2016; 147:234-241. [DOI: 10.1016/j.colsurfb.2016.07.064] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/16/2016] [Accepted: 07/31/2016] [Indexed: 11/23/2022]
|
90
|
Li H, Chen G, Das S. Electric double layer electrostatics of pH-responsive spherical polyelectrolyte brushes in the decoupled regime. Colloids Surf B Biointerfaces 2016; 147:180-190. [DOI: 10.1016/j.colsurfb.2016.07.049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/20/2016] [Accepted: 07/25/2016] [Indexed: 11/29/2022]
|
91
|
Mahalik JP, Sumpter BG, Kumar R. Vertical Phase Segregation Induced by Dipolar Interactions in Planar Polymer Brushes. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01138] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Jyoti P. Mahalik
- Computer
Science and Mathematics
Division and Center for Nanophase Materials
Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Bobby G. Sumpter
- Computer
Science and Mathematics
Division and Center for Nanophase Materials
Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Rajeev Kumar
- Computer
Science and Mathematics
Division and Center for Nanophase Materials
Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| |
Collapse
|
92
|
Wei J, Song F, Dobnikar J. Assembly of Superparamagnetic Filaments in External Field. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:9321-8. [PMID: 27536958 DOI: 10.1021/acs.langmuir.6b02268] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We present a theoretical and simulation study of anchored magneto-elastic filaments in external magnetic field. The filaments are composed of a mixture of superparamagnetic and nonmagnetic colloidal beads interlinked with elastic springs. We explore the steady-state structures of filaments with various composition and bending rigidity subject to external magnetic field parallel to the surface. The interplay of elastic and induced magnetic interactions results in a rich phase behavior with morphologies reminiscent of macromolecular folding: bent filaments, loops, sheets, helicoids, and other collapsed structures. Our results provide new insights into the design of hierarchically assembled supramolecular structures with controlled response to external stimuli.
Collapse
Affiliation(s)
- Jiachen Wei
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences , 15 Beisihuanxi Road, Beijing 100190, China
- School of Engineering Science, University of Chinese Academy of Sciences , Beijing 100049, China
| | - Fan Song
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences , 15 Beisihuanxi Road, Beijing 100190, China
- School of Engineering Science, University of Chinese Academy of Sciences , Beijing 100049, China
| | - Jure Dobnikar
- Institute of Physics, Chinese Academy of Sciences , 8 Third South Street, Zhongguancun, Beijing 100190, China
- International Research Center for Soft Matter, Beijing University of Chemical Technology , 15 Beisanhuan Road, Beijing 100029, China
| |
Collapse
|
93
|
Poddar A, Maity D, Bandopadhyay A, Chakraborty S. Electrokinetics in polyelectrolyte grafted nanofluidic channels modulated by the ion partitioning effect. SOFT MATTER 2016; 12:5968-5978. [PMID: 27306568 DOI: 10.1039/c6sm00275g] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The effects of ion partitioning on the electrokinetics in a polyelectrolyte grafted nanochannel, which is the representative of a soft nanochannel, are analyzed. Earlier studies in this regard have considered low polyelectrolyte layer (PEL) grafting density at the rigid nanochannel wall and, hence, an equal permittivity inside and outside the grafted layer. In order to overcome this shortcoming, the concept of Born energy is revisited. The coupled system of the modified Poisson-Boltzmann and Navier-Stokes equation is solved numerically, going beyond the widely employed Debye-Hückel linearization and low PEL densities. The complex interplay between the hydrodynamics and charge distribution, modulated by the ion partitioning effect, along with their consequent effects on the streaming potential and electrokinetic energy conversion efficiency (EKEC) have been systemically investigated. It has been observed that the ion partitioning effect reduces the EKEC in comparison to the case with equal permittivity up to a certain electrical double layer thickness after which it increases the EKEC. For a high concentration of mobile charges within the PEL, the net gain in the maximum EKEC due to the ion partitioning effect is about 10 fold that of the case when the ion partitioning effect is not considered. We delve into the various scaling regimes in the streaming potential and intriguingly point out the exact location of peaks in efficiency. The present study also reveals the possibility of improvement in streaming potential mediated energy conversion by the use of polyelectrolyte materials, which possess substantially lower dielectric permittivity than the bulk electrolyte.
Collapse
Affiliation(s)
- Antarip Poddar
- Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur, India-721302.
| | - Debonil Maity
- Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur, India-721302.
| | - Aditya Bandopadhyay
- Advanced Technology Development Center, Indian Institute of Technology Kharagpur, Kharagpur, India-721302
| | - Suman Chakraborty
- Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur, India-721302. and Advanced Technology Development Center, Indian Institute of Technology Kharagpur, Kharagpur, India-721302
| |
Collapse
|
94
|
Chen G, Das S. Anomalous Shrinking–Swelling of Nanoconfined End-Charged Polyelectrolyte Brushes: Interplay of Confinement and Electrostatic Effects. J Phys Chem B 2016; 120:6848-57. [DOI: 10.1021/acs.jpcb.6b04636] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Guang Chen
- Department
of Mechanical
Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Siddhartha Das
- Department
of Mechanical
Engineering, University of Maryland, College Park, Maryland 20742, United States
| |
Collapse
|
95
|
Bhagawati M, Rubashkin MG, Lee JP, Ananthanarayanan B, Weaver VM, Kumar S. Site-Specific Modulation of Charge Controls the Structure and Stimulus Responsiveness of Intrinsically Disordered Peptide Brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:5990-5996. [PMID: 27203736 PMCID: PMC5343758 DOI: 10.1021/acs.langmuir.6b01099] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Intrinsically disordered proteins (IDPs) are an important and emerging class of materials for tailoring biointerfaces. While the importance of chain charge and resultant electrostatic interactions in controlling conformational properties of IDPs is beginning to be explored through in silico approaches, there is a dearth of experimental studies motivated toward a systematic study of these effects. In an effort to explore this relationship, we measured the conformations of two peptides derived from the intrinsically disordered neurofilament (NF) side arm domain: one depicting the wild-type sequence with four lysine-serine-proline repeats (KSP peptide) and another in which the serine residues were replaced with aspartates (KDP peptide), a strategy sometimes used to mimic phosphorylation. Using a variety of biophysical measurements including a novel application of scanning angle interference microscopy, we demonstrate that the KDP peptide assumes comparatively more expanded conformations in solution and forms significantly thicker brushes when immobilized on planar surfaces at high densities. In both settings, the peptides respond to changes in ambient ionic strength, with each peptide showing distinct stimulus-responsive characteristics. While the KDP peptide undergoes compaction with increasing ionic strength as would be expected for a polyampholyte, the KSP peptide shows biphasic behavior, with an initial compaction followed by an expanded state at a higher ionic strength. Together these results support the notion that modulation of charge on IDPs can regulate conformational and interfacial properties.
Collapse
Affiliation(s)
- Maniraj Bhagawati
- Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Matt G. Rubashkin
- Center for Bioengineering and Tissue Regeneration, University of California, San Francisco, San Francisco, California 94143, United States
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Jessica P. Lee
- Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | | | - Valerie M. Weaver
- Center for Bioengineering and Tissue Regeneration, University of California, San Francisco, San Francisco, California 94143, United States
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Sanjay Kumar
- Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States
| |
Collapse
|
96
|
Chen G, Li H, Das S. Scaling Relationships for Spherical Polymer Brushes Revisited. J Phys Chem B 2016; 120:5272-7. [DOI: 10.1021/acs.jpcb.6b01609] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Guang Chen
- Department
of Mechanical
Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Hao Li
- Department
of Mechanical
Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Siddhartha Das
- Department
of Mechanical
Engineering, University of Maryland, College Park, Maryland 20742, United States
| |
Collapse
|
97
|
Tong M, An X, Pan W, Liu H, Zhao Y. Synthesis and properties of stimuli-sensitive heterografted toothbrush-like terpolymers with a linear handle and two types of V-shaped grafts. Polym Chem 2016. [DOI: 10.1039/c6py00182c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Straightforward syntheses were performed to generate amphiphilic heterograftedPNIPAM(PAA)2m(PCL)2mcopolymers, which could self-assemble into versatile nanoobjects for thermo, pH and additive triggered controlled release of doxorubicin.
Collapse
Affiliation(s)
- Min Tong
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- College of Chemistry
- Chemical Engineering and Materials Science
| | - Xiaonan An
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- College of Chemistry
- Chemical Engineering and Materials Science
| | - Weidong Pan
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- College of Chemistry
- Chemical Engineering and Materials Science
| | - Huanhuan Liu
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- College of Chemistry
- Chemical Engineering and Materials Science
| | - Youliang Zhao
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- College of Chemistry
- Chemical Engineering and Materials Science
| |
Collapse
|
98
|
Levin A, Erlkamp M, Steitz R, Czeslik C. Volume profile of α-chymotrypsin during adsorption and enzymatic reaction on a poly(acrylic acid) brush. Phys Chem Chem Phys 2016; 18:9070-8. [DOI: 10.1039/c6cp00843g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The catalytic rate of α-chymotrypsin that is adsorbed on a poly(acrylic acid) brush can be enhanced by pressure.
Collapse
Affiliation(s)
- Artem Levin
- TU Dortmund University
- Department of Chemistry and Chemical Biology
- D-44221 Dortmund
- Germany
| | - Mirko Erlkamp
- TU Dortmund University
- Department of Chemistry and Chemical Biology
- D-44221 Dortmund
- Germany
| | - Roland Steitz
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH
- D-14109 Berlin
- Germany
| | - Claus Czeslik
- TU Dortmund University
- Department of Chemistry and Chemical Biology
- D-44221 Dortmund
- Germany
| |
Collapse
|