Exploring the hydrated microstructure and molecular mobility in blend polyelectrolyte membranes by quantum mechanics and molecular dynamics simulations

RSC Advances ◽  
2016 ◽  
Vol 6 (42) ◽  
pp. 35517-35526 ◽  
Author(s):  
Ghasem Bahlakeh ◽  
Mohammad Mahdi Hasani-Sadrabadi ◽  
Karl I. Jacob

QMs and MD simulations were employed to investigate the effect of water contents and temperatures on structural and dynamical behaviors of blended PEMs.

2019 ◽  
Vol 21 (2) ◽  
pp. 702-717 ◽  
Author(s):  
Bienvenu Atawa ◽  
Natália T. Correia ◽  
Nicolas Couvrat ◽  
Frédéric Affouard ◽  
Gérard Coquerel ◽  
...  

Molecular mobility of NAC-MBA molecule is described by means of DRS, FSC and MD simulations.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Andrey Sarikov ◽  
Anna Marzegalli ◽  
Luca Barbisan ◽  
Massimo Zimbone ◽  
Corrado Bongiorno ◽  
...  

In this work, annihilation mechanism of stacking faults (SFs) in epitaxial 3C-SiC layers grown on Si(001) substrates is studied by molecular dynamics (MD) simulations. The evolution of SFs located in...


2016 ◽  
Vol 18 (37) ◽  
pp. 25806-25816 ◽  
Author(s):  
Carlos Navarro-Retamal ◽  
Anne Bremer ◽  
Jans Alzate-Morales ◽  
Julio Caballero ◽  
Dirk K. Hincha ◽  
...  

Unfolding of intrinsically unstructured full-length LEA proteins in a differentially crowded environment can be modeled by 30 ns MD simulations in accordance with experimental data.


2011 ◽  
Vol 10 (03) ◽  
pp. 359-370 ◽  
Author(s):  
JUAN PANG ◽  
HU YANG ◽  
JING MA ◽  
RONGSHI CHENG

Poly(N-alkylacrylamide) is a group of thermo-sensitive polymers that include poly (N-isopropylacrylamide), poly(N-n-propylacrylamide), poly(N-isopropylmethacryl-amide), and so on. The polymers exhibit different levels of lower critical solution temperatures (LCST) in aqueous solutions. In this article, their monomers and oligomers with 10 repeating units are selected, respectively, to demonstrate the cause of different LCST levels of the polymers in aqueous solutions using molecular dynamics simulations and quantum mechanics calculations. The monomers have functional groups of different steric volume that greatly affect the conformational transition of chains and LCST levels of the polymers. A branched chain of N-propyl group in N-isopropylacrylamide and an additional methyl group at α-carbon in N-isopropylmethacrylamide both increase the steric effect, making it more difficult for monomers to draw closer and resulting in higher LCST levels of the polymers. In addition, the simulated results from their corresponding oligomers exhibit the similar trend to those from the monomers.


2005 ◽  
Vol 1 (4) ◽  
pp. 204-209
Author(s):  
O.B. Malcıoğlu ◽  
Ş. Erkoç

The minimum energy structures of CmTin microclusters and nanoparticles have been investigated theoretically by performing molecular–dynamics (MD) simulations. Selected crystalline and completely random initial geometries are considered. The potential energy function (PEF) used in the calculations includes two– and three–body atomic interactions for C-Ti binary systems. Molecular–dynamics simulations have been performed at 1 K and 300 K. It has been found that initial geometry has a very strong influence on relaxed geometry


2013 ◽  
Vol 9 ◽  
pp. 118-134 ◽  
Author(s):  
Jutta Erika Helga Köhler ◽  
Nicole Grczelschak-Mick

Four highly ordered hydrogen-bonded models of β-cyclodextrin (β-CD) and its inclusion complex with benzene were investigated by three different theoretical methods: classical quantum mechanics (QM) on AM1 and on the BP/TZVP-DISP3 level of approximation, and thirdly by classical molecular dynamics simulations (MD) at different temperatures (120 K and 273 to 300 K). The hydrogen bonds at the larger O2/O3 rim of empty β-CDs prefer the right-hand orientation, e.g., O3-H…O2-H in the same glucose unit and bifurcated towards …O4 and O3 of the next glucose unit on the right side. On AM1 level the complex energy was −2.75 kcal mol−1 when the benzene molecule was located parallel inside the β-CD cavity and −2.46 kcal mol−1 when it was positioned vertically. The AM1 HOMO/LUMO gap of the empty β-CD with about 12 eV is lowered to about 10 eV in the complex, in agreement with data from the literature. AM1 IR spectra displayed a splitting of the O–H frequencies of cyclodextrin upon complex formation. At the BP/TZVP-DISP3 level the parallel and vertical positions from the starting structures converged to a structure where benzene assumes a more oblique position (−20.16 kcal mol−1 and −20.22 kcal mol−1, resp.) as was reported in the literature. The character of the COSMO-RS σ-surface of β-CD was much more hydrophobic on its O6 rim than on its O2/O3 side when all hydrogen bonds were arranged in a concerted mode. This static QM picture of the β-CD/benzene complex at 0 K was extended by MD simulations. At 120 K benzene was mobile but always stayed inside the cavity of β-CD. The trajectories at 273, 280, 290 and 300 K certainly no longer displayed the highly ordered hydrogen bonds of β-CD and benzene occupied many different positions inside the cavity, before it left the β-CD finally at its O2/O3 side.


2020 ◽  
Vol 22 (12) ◽  
pp. 6690-6697 ◽  
Author(s):  
Aman Jindal ◽  
Sukumaran Vasudevan

Hydrogen bonding OH···O geometries in the liquid state of linear alcohols, derived from ab initio MD simulations, show no change from methanol to pentanol, in contrast to that observed in their crystalline state.


2019 ◽  
Vol 21 (19) ◽  
pp. 9865-9875 ◽  
Author(s):  
Sharmin Shabnam ◽  
Qian Mao ◽  
Adri C. T. van Duin ◽  
K. H. Luo

Effect of nickel clusters on the formation of incipient soot from PAH precursors via ReaxFF-MD simulations.


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