Overbinding of ions is a common and well-known problem in classical molecular dynamics simulations. One its main causes the absence electronic polarizability force fields. The current approaches for minimizing overbinding typically either retain original charges use an ad hoc readjustment Lennard-Jones parameters as done nonbonded fix (NBFIX) approach or rescale using theoretical framework. goal latter to include shielding produced by missing continuum correction (ECC) approach. NBFIX ECC...

ABSTRACT Revealing the way of how modification chemical structure a polymer affects its macroscopic physical properties offers an opportunity to develop novel materials with pre‐defined characteristics. To address this problem two thermoplastic polyimides, ULTEM™ and EXTEM™, were simulated small difference in structures monomer units, namely, phenyl ring was replaced by diphenylsulphone group EXTEM™. It is shown that such results drastic thermal properties: glass transition temperature...

ABSTRACT The paper focuses on the problem of electrostatic interactions in molecular dynamics simulations thermal properties heterocyclic polymers. study three thermoplastic polyimides synthesized basis 1,3‐bis‐(3′,4‐dicarboxyphenoxy)benzene (dianhydride R) and diamines: 4,4′‐ bis ‐(4″‐aminophenoxy) diphenylsulfone (diamine BAPS), biphenyl BAPB), ‐(4''‐aminophenoxy) diphenyloxide BAPO). In these were described by Gromos53a5 force field. To parameterize four methods calculating partial atomic...

Abstract Polymer bio‐nanocomposites are widely used nowadays in various applications. One of the most promising polymers for producing such materials is poly(lactic acid) ( PLA ) filled with cellulose nanocrystals CNCs ). To increase compatibility hydrophobic and hydrophilic cellulose, surface latter can be chemically modified. Among modifications, grafting lactic acid oligomers OLAs special interest. In this paper, first all‐atom molecular dynamics simulation nanocomposites surface‐grafted...

Molecular dynamics (MD) simulation of a nanofibril native bacterial cellulose (BC) in solutions mineral ions is presented. The supersaturated calcium-phosphate (CP) solution with the ionic composition hydroxyapatite and CaCl2 concentrations below, equal to, above solubility limits are simulated. influence solvation models (TIP3P TIP4P-ew water models) on structural characteristics simulated crystal nucleation process assessed. nanofibrils (in particular, surface layer) found to be nearly...

Specific intermolecular interactions, in particular H-bonding, have a strong influence on the structural, thermal and relaxation characteristics of polymers. We report here results molecular dynamics simulations Nylon 6 which provides an excellent example for investigation such influence. To demonstrate effect proper accounting H-bonding bulk polymer properties, AMBER99sb force field is used with two different parametrization approaches leading to sets partial atomic charges. The allowed...

Electrostatic interactions have a determining role in the conformational and dynamic behavior of polyelectrolyte molecules. In this study, anionic molecules, poly(glutamic acid) (PGA) poly(aspartic (PASA), water solution with most commonly used K+ or Na+ counterions, were investigated using atomistic molecular dynamics (MD) simulations. We performed comparison seven popular force fields, namely AMBER99SB-ILDN, AMBER14SB, AMBER-FB15, CHARMM22*, CHARMM27, CHARMM36m OPLS-AA/L, both their native...

The aim of this work was to study the influence water as a co-solvent on interaction between polymerizable ionic liquid—choline acrylate (ChA)—and bacterial cellulose. Bacterial cellulose dispersed in ChA is new type UV-curable biopolymer-based ink that prospective material for 3D printing green composite ion-gels. Higher content inks beneficial ecological and mechanical properties materials, leads increased viscosity yield stress such systems hampers printability. It found addition results...

The interactions responsible for the adhesion of calcium phosphate (CP) nanocrystals and bacterial cellulose (BC) nanofibrils in composite material obtained by mixing aqueous suspensions presynthesized CP BC dependence these on morphology chemical structure have been elucidated molecular mechanics calculations CP–BC interfacial structures. between superficial crystal layers simulated. Two crystalline structures (i.e., hydroxyapatite (HAP) whitlockite) with two morphologies (plate-shaped...

We present results from all-atom molecular dynamics simulations for the structural properties of oligomeric lactic acid chains (OLA) grafted to surface cellulose nanocrystals (CNCs) and immersed in melt polylactic (PLA). Earlier, we have found that distribution free ends OLA molecules is bimodal [Glova et al., Polym. Int., 2016, 65(8), 892]. The cannot be explained within standard picture uncharged polymer brushes exposed a chemically identical polymer. Although are uncharged, they partial...

Molecular-level insight into the interactions of phospholipid molecules with cellulose is crucial for development novel cellulose-based materials wound dressing. Here we employ state-of-the-art computer simulations to unlock first time molecular mechanisms behind such interactions. To this end, performed a series atomic-scale dynamics bilayers on crystalline support at various hydration levels bilayer leaflets next surface. Our findings clearly demonstrate existence strong between polar...

Cellulose can be phosphorylated to produce organic matrices with highly adsorptive properties for, e.g., biocompatible materials for biomedical applications. We focus on the effects of phosphorylation surfaces crystalline nanocellulose and, in particular, competitive adsorption mono- and divalent cations (Na+ Ca2+) typically contained mineralizing salt mixtures using all-atom molecular dynamics (MD) simulations. Phosphorylation was applied at 12% 25% both water CaCl2 solutions. Our main...

Investigation of the effect CaCl2 salt on conformations two anionic poly(amino acids) with different side chain lengths, poly-(α-l glutamic acid) (PGA) and aspartic (PASA), was performed by atomistic molecular dynamics (MD) simulations. The simulations were using both unbiased MD Hamiltonian replica exchange (HRE) method. results show that at low concentration adsorption Ca2+ ions lead to a significant size reduction for PGA PASA. With increase in concentration, chains sizes partially...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOrdered Structures of Poly(p-hydroxybenzoic acid). 1. Nonbonded Interactions in Layers Phenyl Rings Orthogonal to the Chain AxisNatalia V. Lukasheva, Alla Sariban, Thomas Mosell, and Juergen BrickmannCite this: Macromolecules 1994, 27, 17, 4726–4732Publication Date (Print):August 1, 1994Publication History Published online1 May 2002Published inissue 1 August...