scholarly journals Effects of precursor topology and synthesis under crowding conditions on the structure of single-chain polymer nanoparticles

Soft Matter ◽  
2017 ◽  
Vol 13 (37) ◽  
pp. 6430-6438 ◽  
Author(s):  
Maud Formanek ◽  
Angel J. Moreno
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Polymer Nanoparticles ◽  
Cross Linking ◽  
Single Chain ◽  
Chain Polymer ◽  
Ring Polymers ◽  
Concentrated Solution ◽  
Dynamics Simulations

By means of molecular dynamics simulations, we investigate the formation of single-chain nanoparticles through intramolecular cross-linking of linear and ring polymers, in the presence of their precursors acting as purely steric crowders in concentrated solution.

scholarly journals Effects of Topological Constraints on Penetration Structures of Semi-Flexible Ring Polymers

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2659
Author(s):  
Fuchen Guo ◽  
Ke Li ◽  
Jiaxin Wu ◽  
Linli He ◽  
Linxi Zhang
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Effective Potential ◽  
Topological Constraints ◽  
Chain Stiffness ◽  
Ring Polymers ◽  
Dynamics Simulations ◽  
Flexible Ring ◽  
Peak Value ◽  
Improved Algorithm

The effects of topological constraints on penetration structures of semi-flexible ring polymers in a melt are investigated using molecular dynamics simulations, considering simultaneously the effects of the chain stiffness. Three topology types of rings are considered: 01-knot (the unknotted), 31-knot and 61-knot ring polymers, respectively. With the improved algorithm to detect and quantify the inter-ring penetration (or inter-ring threading), the degree of ring threading does not increase monotonously with the chain stiffness, existing a peak value at the intermediate stiffness. It indicates that rings interpenetrate most at intermediate stiffness where there is a balance between coil expansion (favoring penetrations) and stiffness (inhibiting penetrations). Meanwhile, the inter-ring penetration would be suppressed with the knot complexity of the rings. The analysis of effective potential between the rings provides a better understanding for this non-monotonous behavior in inter-ring penetration.

scholarly journals Solving protein structures using short-distance cross-linking constraints as a guide for discrete molecular dynamics simulations

2017 ◽  
Vol 3 (7) ◽  
pp. e1700479 ◽  
Author(s):  
Nicholas I. Brodie ◽  
Konstantin I. Popov ◽  
Evgeniy V. Petrotchenko ◽  
Nikolay V. Dokholyan ◽  
Christoph H. Borchers
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Short Distance ◽  
Protein Structures ◽  
Cross Linking ◽  
Discrete Molecular Dynamics ◽  
Dynamics Simulations

Permanent Set of Cross-Linking Networks:  Comparison of Theory with Molecular Dynamics Simulations

2006 ◽  
Vol 39 (16) ◽  
pp. 5521-5530 ◽  
Author(s):  
Dana R. Rottach ◽  
John G. Curro ◽  
Joanne Budzien ◽  
Gary S. Grest ◽  
Carsten Svaneborg ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Cross Linking ◽  
Permanent Set ◽  
Dynamics Simulations

Thermal Conductivity of Polyethylene Chains Using Molecular Dynamics Simulations

2008 ◽  
Author(s):  
Asegun Henry ◽  
Gang Chen
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Polymer Chains ◽  
High Thermal Conductivity ◽  
Polymer Materials ◽  
Single Chain ◽  
Wide Range ◽  
Dynamics Simulations ◽  
Limiting Case

We used molecular dynamics simulations to calculate the thermal conductivity of polyethylene chains, by employing the widely used Green-Kubo formula. The simulations use the AIREBO potential and employ periodic boundary conditions to mimic the dynamics of an infinite chain. In this limiting case, we observed that when the simulation domain is large enough the thermal conductivity diverges. The results suggest that single polymer chains intrinsically have high thermal conductivity. Although polymers are generally known to have low thermal conductivity, our observation of divergent thermal conductivity in a single chain suggests that high thermal conductivity polymer materials can be engineered, which would be of interest to a wide range of applications.

Organometallic single-chain polymer nanoparticles via intra-chain cross-linking with dinuclear μ-halo(diene)Rh(I) complexes

2021 ◽  
pp. 104971
Author(s):  
Victoria Kobernik ◽  
Ravindra Suresh Phatake ◽  
Jonathan Tzadikov ◽  
Ofer Reany ◽  
N. Gabriel Lemcoff
Keyword(s):  
Polymer Nanoparticles ◽  
Cross Linking ◽  
Single Chain ◽  
Chain Polymer

scholarly journals Strong reduction of the chain rigidity of hyaluronan by selective binding of Ca2+ ions

2020 ◽  
Author(s):  
G. Giubertoni ◽  
A. Pérez de Alba Ortíz ◽  
F. Bano ◽  
X. Zhang ◽  
R.J. Linhardt ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Electrostatic Interactions ◽  
Structural Changes ◽  
Polymer Chains ◽  
Single Chain ◽  
Molecular Hydrogen Bond ◽  
Dynamics Simulations ◽  
Chain Force ◽  
Molecular Picture

ABSTRACTThe biological functions of natural polyelectrolytes are strongly influenced by the presence of ions, which bind to the polymer chains and thereby modify their properties. Although the biological impact of such modifications is well-recognized, a detailed molecular picture of the binding process and of the mechanisms that drive the subsequent structural changes in the polymer is lacking. Here, we study the molecular mechanism of the condensation of calcium, a divalent cation, on hyaluronan, a ubiquitous polymer in human tissues. By combining two-dimensional infrared spectroscopy experiments with molecular dynamics simulations, we find that calcium specifically binds to hyaluronan at millimolar concentrations. Because of its large size and charge, the calcium cation can bind simultaneously to the negatively charged carboxylate group and the amide group of adjacent saccharide units. Molecular dynamics simulations and single-chain force spectroscopy measurements provide evidence that the binding of the calcium ions weakens the intra-molecular hydrogen-bond network of hyaluronan, increasing the flexibility of the polymer chain. We also observe that the binding of calcium to hyaluronan saturates at a maximum binding fraction of ~10-15 mol %. This saturation indicates that the binding of Ca2+ strongly reduces the probability of subsequent binding of Ca2+ at neighboring binding sites, possibly as a result of enhanced conformational fluctuations and/or electrostatic repulsion effects. Our findings provide a detailed molecular picture of ion condensation, and reveal the severe effect of a few, selective and localized electrostatic interactions on the rigidity of a polyelectrolyte chain.TOC

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