Effect of Concentration on the Supramolecular Polymerization Mechanism via Implicit-Solvent Coarse-Grained Simulations of Water-Soluble 1,3,5-Benzenetricarboxamide

2017 ◽  
Vol 8 (16) ◽  
pp. 3813-3819 ◽  
Author(s):  
Davide Bochicchio ◽  
Giovanni M. Pavan
Keyword(s):  
Water Soluble ◽  
Coarse Grained ◽  
Implicit Solvent ◽  
Polymerization Mechanism ◽  
Coarse Grained Simulations ◽  
Supramolecular Polymerization

scholarly journals Coarse-Grained Simulations of the Effects of Chain Length, Solvent Quality, and Chemical Defects on the Solution-Phase Morphology of MEH-PPV Conjugated Polymers

2012 ◽  
Vol 65 (5) ◽  
pp. 463 ◽  
Author(s):  
Ming Chiu ◽  
Tak W. Kee ◽  
David M. Huang
Keyword(s):  
Polymer Chains ◽  
Coarse Grained ◽  
Radius Of Gyration ◽  
Implicit Solvent ◽  
Coarse Grained Model ◽  
Solvent Quality ◽  
Defect Content ◽  
Coarse Grained Simulations ◽  
Chain Lengths ◽  
Poor Solvent

A mesoscale coarse-grained model of the conjugated polymer poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) in implicit solvent is developed. The model is parametrized to reproduce the local structure and dynamics of an atomistic simulation model and accounts for the effects of solvent quality and saturation chemical defects on the polymer structure. Polymers with defect concentrations of 0 to 10 % are simulated using Langevin dynamics in tetrahydrofuran (THF) and in a model poor solvent for chain lengths and solution concentrations used experimentally. The polymer chains are extended in THF and collapse into compact structures in the poor solvent. The radius of gyration decreases with defect content in THF and agrees quantitatively with experiment. The structures formed in poor solvent by chains with 300 monomer units change from toroidal to cylindrical with increasing defect content, while chains containing 1000 monomers form cylinders regardless of defect content. These results have implications for energy transfer in MEH-PPV.

Corrigendum to: Coarse-Grained Simulations of the Effects of Chain Length, Solvent Quality, and Chemical Defects on the Solution-Phase Morphology of MEH-PPV Conjugated Polymers

2013 ◽  
Vol 66 (4) ◽  
pp. 505
Author(s):  
Ming Chiu ◽  
Tak W. Kee ◽  
David M. Huang
Keyword(s):  
Polymer Chains ◽  
Coarse Grained ◽  
Radius Of Gyration ◽  
Implicit Solvent ◽  
Coarse Grained Model ◽  
Solvent Quality ◽  
Defect Content ◽  
Coarse Grained Simulations ◽  
Chain Lengths ◽  
Poor Solvent

A mesoscale coarse-grained model of the conjugated polymer poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) in implicit solvent is developed. The model is parametrized to reproduce the local structure and dynamics of an atomistic simulation model and accounts for the effects of solvent quality and saturation chemical defects on the polymer structure. Polymers with defect concentrations of 0 to 10 % are simulated using Langevin dynamics in tetrahydrofuran (THF) and in a model poor solvent for chain lengths and solution concentrations used experimentally. The polymer chains are extended in THF and collapse into compact structures in the poor solvent. The radius of gyration decreases with defect content in THF and agrees quantitatively with experiment. The structures formed in poor solvent by chains with 300 monomer units change from toroidal to cylindrical with increasing defect content, while chains containing 1000 monomers form cylinders regardless of defect content. These results have implications for energy transfer in MEH-PPV.

Grand-Reaction Method for Simulations of Ionization Equilibria and Ion Partitioning in a Broad Range of pH and Ionic Strength

2019 ◽  
Author(s):  
Jonas Landsgesell ◽  
Oleg Rud ◽  
Pascal Hebbeker ◽  
Raju Lunkad ◽  
Peter Košovan ◽  
...  
Keyword(s):  
Mean Field ◽  
Coarse Grained ◽  
Reactive System ◽  
Acid Base ◽  
Buffer Solution ◽  
Reaction Method ◽  
Ionization Equilibria ◽  
Coarse Grained Simulations ◽  
Ph Range ◽  
Weak Polyelectrolytes

We introduce the grand-reaction method for coarse-grained simulations of acid-base equilibria in a system coupled to a reservoir at a given pH and concentration of added salt. It can be viewed as an extension of the constant-pH method and the reaction ensemble, combining explicit simulations of reactions within the system, and grand-canonical exchange of particles with the reservoir. Unlike the previously introduced methods, the grand-reaction method is applicable to acid-base equilibria in the whole pH range because it avoids known artifacts. However, the method is more general, and can be used for simulations of any reactive system coupled to a reservoir of a known composition. To demonstrate the advantages of the grand-reaction method, we simulated a model system: A solution of weak polyelectrolytes in equilibrium with a buffer solution. By carefully accounting for the exchange of all constituents, the method ensures that all chemical potentials are equal in the system and in the multi-component reservoir. Thus, the grand-reaction method is able to predict non-monotonic swelling of weak polyelectrolytes as a function of pH, that has been known from mean-field predictions and from experiments but has never been observed in coarse-grained simulations. Finally, we outline possible extensions and further generalizations of the method, and provide a set of guidelines to enable safe usage of the method by a broad community of users.<br><br>

scholarly journals Solubilization of Charged Porphyrins in Interpolyelectrolyte Complexes: A Computer Study

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 502
Author(s):  
Karel Šindelka ◽  
Zuzana Limpouchová ◽  
Karel Procházka
Keyword(s):  
Dissipative Particle Dynamics ◽  
Water Soluble ◽  
Coarse Grained ◽  
Core Shell ◽  
Computer Study ◽  
Interpolyelectrolyte Complex ◽  
The Core ◽  
Porphyrin Derivatives ◽  
Oppositely Charged ◽  
Positively Charged

Using coarse-grained dissipative particle dynamics (DPD) with explicit electrostatics, we performed (i) an extensive series of simulations of the electrostatic co-assembly of asymmetric oppositely charged copolymers composed of one (either positively or negatively charged) polyelectrolyte (PE) block A and one water-soluble block B and (ii) studied the solubilization of positively charged porphyrin derivatives (P+) in the interpolyelectrolyte complex (IPEC) cores of co-assembled nanoparticles. We studied the stoichiometric mixtures of 137 A10+B25 and 137 A10−B25 chains with moderately hydrophobic A blocks (DPD interaction parameter aAS=35) and hydrophilic B blocks (aBS=25) with 10 to 120 P+ added (aPS=39). The P+ interactions with other components were set to match literature information on their limited solubility and aggregation behavior. The study shows that the moderately soluble P+ molecules easily solubilize in IPEC cores, where they partly replace PE+ and electrostatically crosslink PE− blocks. As the large P+ rings are apt to aggregate, P+ molecules aggregate in IPEC cores. The aggregation, which starts at very low loadings, is promoted by increasing the number of P+ in the mixture. The positively charged copolymers repelled from the central part of IPEC core partially concentrate at the core-shell interface and partially escape into bulk solvent depending on the amount of P+ in the mixture and on their association number, AS. If AS is lower than the ensemble average ⟨AS⟩n, the copolymer chains released from IPEC preferentially concentrate at the core-shell interface, thus increasing AS, which approaches ⟨AS⟩n. If AS>⟨AS⟩n, they escape into the bulk solvent.

scholarly journals Prediction and validation of protein intermediate states from structurally rich ensembles and coarse-grained simulations

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Laura Orellana ◽  
Ozge Yoluk ◽  
Oliver Carrillo ◽  
Modesto Orozco ◽  
Erik Lindahl
Keyword(s):  
Coarse Grained ◽  
Intermediate States ◽  
Coarse Grained Simulations

Effect of oligonucleic acid (ONA) backbone features on assembly of ONA–star polymer conjugates: a coarse-grained molecular simulation study

Soft Matter ◽  
2017 ◽  
Vol 13 (38) ◽  
pp. 6770-6783 ◽  
Author(s):  
Joshua E. Condon ◽  
Arthi Jayaraman
Keyword(s):  
Molecular Simulation ◽  
Simulation Study ◽  
Coarse Grained ◽  
Star Polymer ◽  
Backbone Flexibility ◽  
Polymer Architecture ◽  
Polymer Conjugates ◽  
Coarse Grained Simulations

Using coarse-grained simulations, we study the effect of varying oligonucleic acid (ONA) backbone flexibility, ONA charge and star polymer architecture on structure and thermodynamics of ONA–star polymer conjugates assembly.

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