1
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Kurbatov AO, Balabaev NK, Litvin KA, Kramarenko EY. Structure and Mechanical Response of Polybutylcarbosilane Dendrimers Confined in a Flat Slit: Effect of Molecular Architecture and Generation Number. Polymers (Basel) 2023; 15:4040. [PMID: 37896283 PMCID: PMC10610163 DOI: 10.3390/polym15204040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/05/2023] [Accepted: 10/07/2023] [Indexed: 10/29/2023] Open
Abstract
Due to the absence of specific interactions, carbosilane dendrimers are ideal models to study the effect of a hyperbranched regular structure on the molecular response to external influences. In this work, we have studied the conformational behavior of single polybutylcarbosilane dendrimers under confinement between impermeable flat surfaces using atomistic molecular dynamics simulations. Dendrimers of different generations belonging to two homologous series with a tetra-functional core and three- and four-functional branches were simulated. The analysis of the dependence of the internal energy of the dendrimers on the wall distance allowed us to determine the critical degree of compression at which the dendrimers are able to change their shape without energy loss. The effects of generation number and branching functionality on the number of wall contacts, density distribution and shape changes were elucidated. It was found that for high generation dendrimers, the inner layers are not accessible for external interaction. It was shown that the excess stresses occurring at high compressions are concentrated in the structural center of the dendrimer. The nature of the elastic response, which is strongly nonlinear, was analyzed at different compressions depending on the dendrimer architecture and generation. We believe that our results are useful for further studies of dendrimer films under compression and can also serve as a basis for developing model concepts to describe the dynamics of dendrimer melts.
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Affiliation(s)
- Andrey O. Kurbatov
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia; (A.O.K.); (K.A.L.)
- Enikolopov Institute of Synthetic Polymeric Materials RAS, Moscow 119991, Russia
| | - Nikolay K. Balabaev
- Institute of Mathematical Problems of Biology RAS—The Branch of Keldysh Institute of Applied Mathematics of Russian Academy of Sciences, Pushchino 142290, Moscow Region, Russia;
| | - Kirill A. Litvin
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia; (A.O.K.); (K.A.L.)
| | - Elena Yu. Kramarenko
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia; (A.O.K.); (K.A.L.)
- Enikolopov Institute of Synthetic Polymeric Materials RAS, Moscow 119991, Russia
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2
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Dockhorn R, Sommer JU. Theory of chain walking catalysis: From disordered dendrimers to dendritic bottle-brushes. J Chem Phys 2022; 157:044902. [DOI: 10.1063/5.0098263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The chain walking (CW) polymerization technique has the unique property of a movable catalyst synthesizing its own path by creating branch-on-branch structures. By successive attachment of monomers, the resulting architecture ranges from dendritic to linear growth depending on the walking rate, which is defined by the ratio of walking steps and reaction events of the catalyst. The transition regime is characterized by local dendritic sub-structures (dendritic blobs) and a global linear chain feature forming a dendritic bottle-brush. A scaling model for structures obtained by CW catalysis is presented and validated by computer simulation relating the extensions of CW structures to the catalyst’s walking ability. The limiting case of linear (low walking rate) and dendritic growth (high walking rate) is recovered, and the latter is shown to bear analogies to the Barabási–Albert graph and Bernoulli growth random walk. We could quantify the size of the dendritic blob as a function of the walking rate by using spectral properties of the connectivity matrix of the simulated macromolecules. This allows us to fit the numerical constants in the scaling approach. We predict that independent of the underlying chemical process, all CW polymerization syntheses involving a highly mobile catalyst ultimately result in bottle-brush structures whose properties depend on a unique parameter: the walking rate.
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Affiliation(s)
- R. Dockhorn
- Institute Theory of Polymers, Leibniz Institute of Polymer Research Dresden, Hohe Strasse 6, D-01069 Dresden, Germany
| | - J.-U. Sommer
- Institute Theory of Polymers, Leibniz Institute of Polymer Research Dresden, Hohe Strasse 6, D-01069 Dresden, Germany
- Institute for Theoretical Physics, Technische Universität Dresden, D-01069 Dresden, Germany
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3
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Kłos JS, Paturej J. Binding mechanisms in dendrimer-surfactant complexes. Phys Rev E 2022; 105:034501. [PMID: 35428143 DOI: 10.1103/physreve.105.034501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
Molecular dynamics simulations were employed to investigate the impact of interactions between dendritic polyeclectrolytes and amphiphilic surfactants on the supramolecular complex formation. We recognize two crucial parameters that govern association of surfactants within dendrimers: surfactant hydrophobicity, ε^{*}, and dendrimer generation, G. We find that depending on the values of ε^{*} and G encapsulation of surfactants by dendrimers is either noncooperative or cooperative. The noncooperative binding is characterized by absorption of surfactants as unimers, whereas in cooperative binding absorption of unimers is followed by aggregate formation through hydrophobic attractions between the surfactant tails. Our results provide guidelines for controlled encapsulation of guest molecules in dendrimer-based guest-host complexes.
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Affiliation(s)
- J S Kłos
- Faculty of Physics, A. Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
- Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany
| | - J Paturej
- Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany
- Institute of Physics, University of Silesia, 75 Pułku Piechoty 1, 41-500 Chorzów, Poland
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4
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Engineering surface amphiphilicity of polymer nanostructures. Prog Polym Sci 2022. [DOI: 10.1016/j.progpolymsci.2021.101489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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5
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Markelov DA, Semisalova AS, Mazo MA. Formation of a Hollow Core in Dendrimers in Solvents. MACROMOL CHEM PHYS 2021. [DOI: 10.1002/macp.202100085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Denis A. Markelov
- Saint Petersburg State University Universitetskaya nab. 7/9 St. Petersburg 199034 Russia
| | - Anna S. Semisalova
- Faculty of Physics and CENIDE University of Duisburg‐Essen Lotharstr. 1 Duisburg 47057 Germany
| | - Mikhail A. Mazo
- Semenov Institute of Chemical Physics Russian Academy of Sciences Kosygina 4 Moscow 119991 Russia
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6
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Wengenmayr M, Dockhorn R, Sommer JU. Multimolecular Structure Formation with Linear Dendritic Copolymers. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Martin Wengenmayr
- Institute Theory of Polymers, Leibniz Institute for Polymer Research Dresden, Hohe Strasse 6, D-01069 Dresden, Germany
| | - Ron Dockhorn
- Institute Theory of Polymers, Leibniz Institute for Polymer Research Dresden, Hohe Strasse 6, D-01069 Dresden, Germany
| | - Jens-Uwe Sommer
- Institute Theory of Polymers, Leibniz Institute for Polymer Research Dresden, Hohe Strasse 6, D-01069 Dresden, Germany
- Institute of Theoretical Physics, Technische Universität Dresden, Zellescher Weg 17, D-01069 Dresden, Germany
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7
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Abrahamsson T, Vagin M, Seitanidou M, Roy A, Phopase J, Petsagkourakis I, Moro N, Tybrandt K, Crispin X, Berggren M, Simon DT. Investigating the role of polymer size on ionic conductivity in free-standing hyperbranched polyelectrolyte membranes. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123664] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Spatial segregation of mixed-sized counterions in dendritic polyelectrolytes. Sci Rep 2021; 11:8108. [PMID: 33854111 PMCID: PMC8046808 DOI: 10.1038/s41598-021-87448-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/30/2021] [Indexed: 11/08/2022] Open
Abstract
Langevin dynamics simulations are utilized to study the structure of a dendritic polyelectrolyte embedded in two component mixtures comprised of conventional (small) and bulky counterions. We vary two parameters that trigger conformational properties of the dendrimer: the reduced Bjerrum length, [Formula: see text], which controls the strength of electrostatic interactions and the number fraction of the bulky counterions, [Formula: see text], which impacts on their steric repulsion. We find that the interplay between the electrostatic and the counterion excluded volume interactions affects the swelling behavior of the molecule. As compared to its neutral counterpart, for weak electrostatic couplings the charged dendrimer exists in swollen conformations whose size remains unaffected by [Formula: see text]. For intermediate couplings, the absorption of counterions into the pervaded volume of the dendrimer starts to influence its conformation. Here, the swelling factor exhibits a maximum which can be shifted by increasing [Formula: see text]. For strong electrostatic couplings the dendrimer deswells correspondingly to [Formula: see text]. In this regime a spatial separation of the counterions into core-shell microstructures is observed. The core of the dendrimer cage is preferentially occupied by the conventional ions, whereas its periphery contains the bulky counterions.
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9
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Hybrid Polycarbosilane-Siloxane Dendrimers: Synthesis and Properties. Polymers (Basel) 2021; 13:polym13040606. [PMID: 33671474 PMCID: PMC7922192 DOI: 10.3390/polym13040606] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/14/2021] [Accepted: 02/15/2021] [Indexed: 11/16/2022] Open
Abstract
A series of carbosilane dendrimers of the 4th, 6th, and 7th generations with a terminal trimethylsilylsiloxane layer was synthesized. Theoretical models of these dendrimers were developed, and equilibrium dendrimer conformations obtained via molecular dynamics simulations were in a good agreement with experimental small-angle X-ray scattering (SAXS) data demonstrating molecule monodispersity and an almost spherical shape. It was confirmed that the glass transition temperature is independent of the dendrimer generation, but is greatly affected by the chemical nature of the dendrimer terminal groups. A sharp increase in the zero-shear viscosity of dendrimer melts was found between the 5th and the 7th dendrimer generations, which was qualitatively identical to that previously reported for polycarbosilane dendrimers with butyl terminal groups. The viscoelastic properties of high-generation dendrimers seem to follow some general trends with an increase in the generation number, which are determined by the regular branching structure of dendrimers.
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10
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Bunker A, Róg T. Mechanistic Understanding From Molecular Dynamics Simulation in Pharmaceutical Research 1: Drug Delivery. Front Mol Biosci 2020; 7:604770. [PMID: 33330633 PMCID: PMC7732618 DOI: 10.3389/fmolb.2020.604770] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/02/2020] [Indexed: 12/12/2022] Open
Abstract
In this review, we outline the growing role that molecular dynamics simulation is able to play as a design tool in drug delivery. We cover both the pharmaceutical and computational backgrounds, in a pedagogical fashion, as this review is designed to be equally accessible to pharmaceutical researchers interested in what this new computational tool is capable of and experts in molecular modeling who wish to pursue pharmaceutical applications as a context for their research. The field has become too broad for us to concisely describe all work that has been carried out; many comprehensive reviews on subtopics of this area are cited. We discuss the insight molecular dynamics modeling has provided in dissolution and solubility, however, the majority of the discussion is focused on nanomedicine: the development of nanoscale drug delivery vehicles. Here we focus on three areas where molecular dynamics modeling has had a particularly strong impact: (1) behavior in the bloodstream and protective polymer corona, (2) Drug loading and controlled release, and (3) Nanoparticle interaction with both model and biological membranes. We conclude with some thoughts on the role that molecular dynamics simulation can grow to play in the development of new drug delivery systems.
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Affiliation(s)
- Alex Bunker
- Division of Pharmaceutical Biosciences, Drug Research Program, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Tomasz Róg
- Department of Physics, University of Helsinki, Helsinki, Finland
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11
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Shavykin OV, Neelov IM, Borisov OV, Darinskii AA, Leermakers FAM. SCF Theory of Uniformly Charged Dendrimers: Impact of Asymmetry of Branching, Generation Number, and Salt Concentration. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c00429] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- O. V. Shavykin
- St. Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University), Kronverkskiy pr. 49, St. Petersburg 197101, Russia
| | - I. M. Neelov
- St. Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University), Kronverkskiy pr. 49, St. Petersburg 197101, Russia
| | - O. V. Borisov
- St. Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University), Kronverkskiy pr. 49, St. Petersburg 197101, Russia
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bolshoi Prospect 31, V.O., St. Petersburg 199004, Russia
- Institut des Sciences Analytiques et de Physico-Chimie pour l’Environnement et les Matériaux/UMR 5254, Pau 64053, France
| | - A. A. Darinskii
- St. Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University), Kronverkskiy pr. 49, St. Petersburg 197101, Russia
- Institute of Macromolecular Compounds, Russian Academy of Sciences, Bolshoi Prospect 31, V.O., St. Petersburg 199004, Russia
| | - F. A. M. Leermakers
- Physical Chemistry and Soft Matter, Wageningen University, Wageningen 6703 HB, The Netherlands
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12
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Affiliation(s)
- J. S. Kłos
- Faculty of Physics, A. Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
- Leibniz Institute of Polymer Research Dresden e.V., 01069 Dresden, Germany
| | - J. Paturej
- Institute of Physics, University of Silesia, 75 Pułku Piechoty 1, 41-500 Chorzów, Poland and
- Leibniz Institute of Polymer Research Dresden e.V., 01069 Dresden, Germany
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13
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Kurbatov AO, Balabaev NK, Mazo MA, Kramarenko EY. Effects of generation number, spacer length and temperature on the structure and intramolecular dynamics of siloxane dendrimer melts: molecular dynamics simulations. SOFT MATTER 2020; 16:3792-3805. [PMID: 32239060 DOI: 10.1039/d0sm00095g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The structure and properties of polysiloxane dendrimer melts are studied by extensive atomistic molecular dynamics simulations. Two homologous series differing in the spacer length are considered. In the first series the dendrimer spacers are the shortest ones, comprising only one oxygen atom, while in the second series the spacers consist of two oxygen atoms with the silicon atom in between. Melts of the dendrimers from the 3rd up to the 6th generation number are modelled in a wide temperature range from 273 to 600 K. A comparative study of the macroscopic melt characteristics such as the melt density and thermal expansion coefficients is performed for the two series. Analysis of the dendrimer structure in melts and in the isolated state shows that intermolecular interactions and interpenetration of dendrimer molecules in melts hardly affect the dendrimer interior organization. However, the presence of neighboring molecules significantly slows down their intramolecular dynamics in melts in comparison with that of isolated dendrimers. An increasing generation number causes an increase of the radius of the dendrimer interior region unavailable for neighboring molecules, which starts to exceed the length of the peripheral interpenetration layer for high-generation dendrimers; this fact could lead to different mechanisms of melt dynamics for lower and higher generation dendrimers.
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Affiliation(s)
- Andrey O Kurbatov
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia. and A. N. Nesmeyanov Institute of Organoelement Compounds RAS, Moscow 119991, Russia
| | - Nikolay K Balabaev
- Institute of Mathematical Problems of Biology, Keldysh Institute of Applied Mathematics RAS, Pushchino, Moscow 142290, Russia
| | - Mikhail A Mazo
- Semenov Institute of Chemical Physics RAS, Moscow 119991, Russia
| | - Elena Yu Kramarenko
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia. and A. N. Nesmeyanov Institute of Organoelement Compounds RAS, Moscow 119991, Russia
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14
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Kłos JS. The Poisson–Boltzmann–Flory Approach to Charged Dendrimers: Effect of Generation and Spacer Length. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00446] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. S. Kłos
- Faculty of Physics, A. Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
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15
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Bergsma J, van der Gucht J, Leermakers FAM. Coarse‐Grained Dendrimers in a Good Solvent: Comparison of Monte Carlo Simulations, Self‐Consistent Field Theory, and a Hybrid Modeling Strategy. MACROMOL THEOR SIMUL 2019. [DOI: 10.1002/mats.201800064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Johan Bergsma
- Physical Chemistry and Soft MatterWageningen University & Research Stippeneng 4 6708 WE Wageningen The Netherlands
| | - Jasper van der Gucht
- Physical Chemistry and Soft MatterWageningen University & Research Stippeneng 4 6708 WE Wageningen The Netherlands
| | - Frans A. M. Leermakers
- Physical Chemistry and Soft MatterWageningen University & Research Stippeneng 4 6708 WE Wageningen The Netherlands
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16
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Wengenmayr M, Dockhorn R, Sommer JU. Dendrimers in Solution of Linear Polymers: Crowding Effects. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Martin Wengenmayr
- Leibniz Institute
of Polymer Research Dresden, Hohe Strasse 6, 01069 Dresden, Germany
| | - Ron Dockhorn
- Leibniz Institute
of Polymer Research Dresden, Hohe Strasse 6, 01069 Dresden, Germany
| | - Jens-Uwe Sommer
- Leibniz Institute
of Polymer Research Dresden, Hohe Strasse 6, 01069 Dresden, Germany
- Institute for Theoretical Physics, Technische Universität Dresden, 01069 Dresden, Germany
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17
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Kurbatov AO, Balabaev NK, Mazo MA, Kramarenko EY. A Comparative Study of Intramolecular Mobility of Single Siloxane and Carbosilane Dendrimers via Molecular Dynamics Simulations. Polymers (Basel) 2018; 10:E838. [PMID: 30960763 PMCID: PMC6403907 DOI: 10.3390/polym10080838] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 07/26/2018] [Accepted: 07/27/2018] [Indexed: 01/27/2023] Open
Abstract
A comparative analysis of intramolecular dynamics of four types of isolated dendrimers from the fourth to the seventh generations belonging to the siloxane and carbosilane families, differing in spacer length, core functionality, and the type of chemical bonds, has been performed via atomic molecular dynamics simulations. The average radial and angular positions of all Si branching atoms of various topological layers within the dendrimer interior, as well as their variations, have been calculated, and the distributions of the relaxation times of their radial and angular motions have been found. It has been shown that the dendrons of all the dendrimers elongate from the center and decrease in a solid angle with an increasing generation number. The characteristic relaxation times of both angular and radial motions of Si atoms are of the order of a few nanoseconds, and they increase with an increasing generation number and decrease with temperature, with the angular relaxation times being larger than the radial ones. The relaxation times in the carbosilanes are larger than those in the siloxanes. The rotational angle dynamics of the carbosilane dendrimers show that the chain bending is mainly realized via trans-gauche transitions in the Si branching bonds.
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Affiliation(s)
- Andrey O Kurbatov
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia.
- A. N. Nesmeyanov Institute of Organoelement Compounds RAS, Moscow 119991, Russia.
| | - Nikolay K Balabaev
- Institute of Mathematical Problems of Biology, Keldysh Institute of Applied Mathematics RAS, Pushchino, Moscow 142290, Russia.
| | - Mikhail A Mazo
- Semenov Institute of Chemical Physics RAS, Moscow 119991, Russia.
| | - Elena Yu Kramarenko
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia.
- A. N. Nesmeyanov Institute of Organoelement Compounds RAS, Moscow 119991, Russia.
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18
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Vasil'ev VG, Kramarenko EY, Tatarinova EA, Milenin SA, Kalinina AA, Papkov VS, Muzafarov AM. An unprecedented jump in the viscosity of high-generation carbosilane dendrimer melts. POLYMER 2018. [DOI: 10.1016/j.polymer.2018.05.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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19
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Kłos JS. Dendritic polyelectrolytes revisited through the Poisson-Boltzmann-Flory theory and the Debye-Hückel approximation. Phys Chem Chem Phys 2018; 20:2693-2703. [PMID: 29319706 DOI: 10.1039/c7cp07138h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The properties of a dendritic polyelectrolyte in equilibrium with a reservoir of monovalent salts are investigated using the cell model and the Poisson-Boltzmann-Flory theory. Within this approach we use the Debye-Hückel approximation to solve the Poisson-Boltzmann equation and minimize the semi-grand potential of the system with respect to the size of the molecule which enables us to inspect its conformations as well as the electric field, the ionic density profile, the overall charge density, the effective charge of the dendrimer and the osmotic pressure based on their response to the salt concentration and the dendrimer charge. The model predicts pronounced trapping of salt ions, a local charge neutrality and a zero electric field in the volume of the molecule as well as oscillations of the density profiles and the electric field in the vicinity of the dendrimer-bulk interface. As a result of ion trapping and screening of Coulomb interactions monovalent salts are found to have a minor effect on the size of the dendrimer. Specifically, the dendrimer exists in slightly swollen states as compared to the neutral molecule which indicates that the conformational properties of the polyelectrolyte depend weakly on monovalent salts. These observations harmonise with the equilibrium behavior of the dendrimer pressure, the internal pressure and the bulk pressure, respectively.
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Affiliation(s)
- J S Kłos
- Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland.
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20
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Kurbatov AO, Balabaev NK, Mazo MA, Kramarenko EY. Molecular dynamics simulations of single siloxane dendrimers: Molecular structure and intramolecular mobility of terminal groups. J Chem Phys 2018; 148:014902. [PMID: 29306281 DOI: 10.1063/1.5009988] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Molecular dynamics simulations of two types of isolated siloxane dendrimers of various generations (from the 2nd to the 8th) have been performed for temperatures ranging from 150 K to 600 K. The first type of dendrimer molecules has short spacers consisting of a single oxygen atom. In the dendrimers of the second type, spacers are longer and comprised of two oxygen atoms separated by a single silicon atom. A comparative analysis of molecular macroscopic parameters such as the gyration radius and the shape factor as well as atom distributions within dendrimer interior has been performed for varying generation number, temperature, and spacer length. It has been found that the short-spacer dendrimers of the 7th and 8th generations have a stressed central part with elongated bonds and deformed valence angles. Investigation of the time evolution of radial displacements of the terminal Si atoms has shown that a fraction of the Si groups have a reduced mobility. Therefore, rather long time trajectories (of the order of tens of nanoseconds) are required to study dendrimer intramolecular dynamics.
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Affiliation(s)
- A O Kurbatov
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
| | - N K Balabaev
- Institute of Mathematical Problems of Biology, Keldysh Institute of Applied Mathematics RAS, Pushchino, Moscow Region 142290, Russia
| | - M A Mazo
- Semenov Institute of Chemical Physics RAS, Moscow 119991, Russia
| | - E Yu Kramarenko
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
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21
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Kłos JS, Milewski J. Dendritic polyelectrolytes as seen by the Poisson–Boltzmann–Flory theory. Phys Chem Chem Phys 2018; 20:17818-17828. [DOI: 10.1039/c8cp02440e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The conformational and electrostatic properties of dendritic polyelectrolytes accompanied by counterions are investigated using the Poisson–Boltzmann–Flory theory.
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Affiliation(s)
- J. S. Kłos
- Faculty of Physics
- A. Mickiewicz University
- 61-614 Poznań
- Poland
- Leibniz Institute of Polymer Research Dresden e.V
| | - J. Milewski
- Institute of Mathematics
- Faculty of Electrical Engineering
- Poznań University of Technology
- 60-963 Poznań
- Poland
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22
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Balabaev NK, Mazo MA, Kramarenko EY. Insight into the Structure of Polybutylcarbosilane Dendrimer Melts via Extensive Molecular Dynamics Simulations. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01639] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- N. K. Balabaev
- Institute
of Mathematical Problems of Biology, Keldysh Institute of Applied Mathematics RAS, Pushchino, Moscow Region 142290, Russia
| | - M. A. Mazo
- Semenov Institute
of Chemical Physics RAS, Moscow 119991, Russia
| | - E. Yu. Kramarenko
- Faculty
of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
- A.N. Nesmeyanov
Institute for Organoelement Compounds RAS, Moscow 119991, Russia
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23
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Shishkin AN, Markelov DA, Matveev VV. Molecular dynamics simulation of poly(butyl)carbosilane dendrimer melts at 600 K. Russ Chem Bull 2016. [DOI: 10.1007/s11172-016-1266-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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24
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Yu C, Ma L, Li K, Li S, Liu Y, Zhou Y, Yan D. Molecular dynamics simulation studies of hyperbranched polyglycerols and their encapsulation behaviors of small drug molecules. Phys Chem Chem Phys 2016; 18:22446-57. [DOI: 10.1039/c6cp03726g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Computer simulation could disclose more details about the conformations of HPGs and their encapsulation behaviors of guest molecules.
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Affiliation(s)
- Chunyang Yu
- School of Chemistry & Chemical Engineering
- State Key Laboratory of Metal Matrix Composites
- Shanghai Jiao Tong University
- Shanghai
- P. R. China
| | - Li Ma
- School of Chemistry & Chemical Engineering
- State Key Laboratory of Metal Matrix Composites
- Shanghai Jiao Tong University
- Shanghai
- P. R. China
| | - Ke Li
- School of Chemistry & Chemical Engineering
- State Key Laboratory of Metal Matrix Composites
- Shanghai Jiao Tong University
- Shanghai
- P. R. China
| | - Shanlong Li
- School of Chemistry & Chemical Engineering
- State Key Laboratory of Metal Matrix Composites
- Shanghai Jiao Tong University
- Shanghai
- P. R. China
| | - Yannan Liu
- School of Chemistry & Chemical Engineering
- State Key Laboratory of Metal Matrix Composites
- Shanghai Jiao Tong University
- Shanghai
- P. R. China
| | - Yongfeng Zhou
- School of Chemistry & Chemical Engineering
- State Key Laboratory of Metal Matrix Composites
- Shanghai Jiao Tong University
- Shanghai
- P. R. China
| | - Deyue Yan
- School of Chemistry & Chemical Engineering
- State Key Laboratory of Metal Matrix Composites
- Shanghai Jiao Tong University
- Shanghai
- P. R. China
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25
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Rabbel H, Frey H, Schmid F. Statistical properties of linear-hyperbranched graft copolymers prepared via “hypergrafting” of ABm monomers from linear B-functional core chains: A molecular dynamics simulation. J Chem Phys 2015; 143:243125. [DOI: 10.1063/1.4935371] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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26
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Welch PM, Welch CF, Henson NJ. Flattening of Dendrimers from Solutions onto Charged Surfaces. ACS Macro Lett 2014; 3:180-184. [PMID: 35590501 DOI: 10.1021/mz400524c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The adsorption of dendrimers onto charged surfaces plays a role in many emerging applications. Numerous studies found in the literature report that dendrimers flatten at these interfaces. Here, we provide a simple scaling theory that describes the height of the adsorbed layer, the fraction of segments within the dendrimer that touch the surface, and the total number of dendrimers adsorbed as a function of generation of growth, surface charge density, and concentration. We demonstrate that these predictions agree well with extensive molecular dynamics simulations. Combined, the simulations and scaling argument indicate that simultaneous adsorption and compression at the interface take place.
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Affiliation(s)
- P. M. Welch
- Theoretical
and Materials Science and Technology Divisions, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, United States
| | - C. F. Welch
- Theoretical
and Materials Science and Technology Divisions, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, United States
| | - N. J. Henson
- Theoretical
and Materials Science and Technology Divisions, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, United States
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