Prediction of intrinsic viscosities of dendritic, hyperbranched and branched polymers

Aerts, J.

doi:10.1016/s1089-3156(98)00013-0

Cited by 41 publications

(15 citation statements)

References 13 publications

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“…Despite the great potential and widespread usage of hyperbranched polymers as functional materials, their polydispersity has hindered detailed experimental studies so that little is known of the atomistic structure and conformations of hyperbranched polymers. , Compared to dendrimers, hyperbranched polymers are generally easy to synthesize in one-step on a large scale, however, this “one-step” procedure usually leads to uncontrolled statistical growth in molecular weight (MW) and degree of branching. , After the first report on hyperbranched polymers by Aerts, a number of synthesis models and relationships between the topology and static properties were investigated − with the help of computer simulations. These theoretical studies have led to two conventional models for hyperbranched polymer growth:…”

Section: Introductionmentioning

confidence: 99%

“…7,21 Compared to dendrimers, hyperbranched polymers are generally easy to synthesize in one-step on a large scale, however, this "one-step" procedure usually leads to uncontrolled statistical growth in molecular weight (MW) and degree of branching. 22,23 After the first report on hyperbranched polymers by Aerts, 24 a number of synthesis models and relationships between the topology and static properties were investigated 25−30 with the help of computer simulations. These theoretical studies have led to two conventional models for hyperbranched polymer growth:…”

Section: Introductionmentioning

confidence: 99%

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pH-Dependent Conformations for Hyperbranched Poly(ethylenimine) from All-Atom Molecular Dynamics

et al. 2018

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Hyperbranched poly(ethylene imine) (PEI) with its high amino content is a versatile functional polymer that is widely used as a gene delivery vector in biological applications and as a ligand and precursor for ion exchange resins and membranes in water purification and metal recovery. We report here the first fully atomistic model of a 25 kDa hyperbranched PEI macromolecule. We utilized this model to carry out molecular dynamics (MD) simulations with explicit water molecules and chloride ions to study pH-dependent conformational changes. We find that growing the PEI macromolecule sequentially from the monomers yields atomistic structures whose sizes (radius of gyration) are in good agreement with the small angle neutron scattering experiments. Our analysis of the structural properties from MD simulations shows that conformations of the hyperbranched PEI exhibit oblate ellipsoidal elongation at low pH compared to high or neutral pH but with no significant changes in the corresponding sizes. This fully atomistic model of a 25 kDa hyperbranched PEI macromolecule in water provides much needed detailed atomistic information for advancing our fundamental understanding of the structures and host−guest properties of PEI-based functional reagents and materials for biomedical and sustainability related applications.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

pH-Dependent Conformations for Hyperbranched Poly(ethylenimine) from All-Atom Molecular Dynamics

et al. 2018

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“…Thus, the irregular branching issue that appears both in real dendrimers due to defects and in truly random hyperbranched polymers (the topic of this work) can be addressed with the aid of computer simulation. In this regard, simulation techniques like Monte Carlo [6,7] and Brownian dynamics [8][9][10] have been employed to compute dilute solution properties of hyperbranched polymers and evaluate the influence of either the degree of polymerization or the degree of branching. The degree of polymerization is straightforwardly represented by the number of elements constituting the polymer model, N (usually a coarse-grained model of beads and connectors).…”

Section: Introductionmentioning

confidence: 99%

Multi-Scale Simulation of Hyperbranched Polymers

2015

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In a previous work, we described a multi-scale protocol for the simulation of the conformation and dynamics of macromolecules that was applied to dendrimer molecules proving its predictive capability by comparison with experimental data. That scheme is now employed in order to predict conformational properties (radius of gyration) and overall hydrodynamic properties (translational diffusion and intrinsic viscosity) of hyperbranched molecules in dilute solution. For that purpose, we use a very simple coarse-grained bead-and-spring model whose parameters are not adjusted against experimental properties but they are obtained from previous atomic-level (Langevin) simulations of small fragments of real hyperbranched polymers. In addition, we devise a method to generate structures with different degree of branching. The Monte Carlo simulation technique was used to generate the set conformations of the coarse-grained model. In spite of the difficulties of reproducing experimental data of highly polydisperse entities (in terms of both molecular weight and topology) without using adjustable parameters, the results of this paper show that the proposed methodology allows for qualitative predictions of the behavior of such complex systems and lead us to conclude that, after some improvement, acceptable quantitative predictions can be achieved.

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“…5 Due to a large number of functional groups and interesting optical, electrochemical, biological, and mechanical properties of hyperbranched molecules, patterning of hyperbranched polymer films is also receiving increased attention. 8 The limitations of this work are the application of the algorithm with no configurational relaxation and the questionable deduction of the intrinsic viscosity from the radius of gyration of branched structures. 5 Hyperbranched polymers such as poly͑phenylenevinylene͒ and polythiophenes have been used as conjugated functional materials because of their good solubility and excellent processibility.…”

Section: Introductionmentioning

confidence: 99%

Structural properties of hyperbranched polymers in the melt under shear via nonequilibrium molecular dynamics simulation

Todd

Daivis

et al. 2009

The Journal of Chemical Physics

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Hyperbranched polymer melts have been simulated using a coarse-grained model and nonequilibrium molecular dynamics (NEMD) techniques. In order to determine the shear-induced changes in the structural properties of hyperbranched polymers, various parameters were calculated at different strain rates. The radii of gyration which characterize the size of the polymer were evaluated. The tensor of gyration was analyzed and results indicate that hyperbranched polymer molecules have a prolate ellipsoid shape under shear. As hyperbranched polymers have compact, highly branched architecture and layers of beads have increasing densities which might lead to an unusual distribution of mass, the distribution of beads was also studied. The distribution of terminal beads was investigated to understand the spatial arrangement of these groups which is very important for hyperbranched polymer applications, especially in drug delivery.

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Prediction of intrinsic viscosities of dendritic, hyperbranched and branched polymers

Cited by 41 publications

References 13 publications

pH-Dependent Conformations for Hyperbranched Poly(ethylenimine) from All-Atom Molecular Dynamics

pH-Dependent Conformations for Hyperbranched Poly(ethylenimine) from All-Atom Molecular Dynamics

Multi-Scale Simulation of Hyperbranched Polymers

Structural properties of hyperbranched polymers in the melt under shear via nonequilibrium molecular dynamics simulation

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