Molecular dynamics simulation of pull-out Halloysite nanotube from polyurethane matrix

Abstract

Molecular dynamics (MD) simulation has been applied to study of pull-out of Halloysite nanotubes (HNTs) from a polyurethane (PU) matrix. First, the Machine learning (ML) particle swarm optimization (PSO) method was used to obtain force field parameters for MD from data of density functional theory (DFT) calculations. The current study shows the possibility of using a PSO technique to modify the force field with DFT data with less than 5 kcal/mol discrepancy. Second, we considered the influence of atomic interface on pulling out of HNT from PU. Energy variation has been proposed as the cohesion strength between matrix and nanoparticle. In addition, the best Lennard Jones parameters in the MD simulation make good agreement with an experimental sample stress-strain response.

Synthesis of N-doped carbon quantum dots as lubricant additive to enhance the tribological behavior of MoS2 nanofluid

“…The average values of potential energy in the equilibrium state for Hence, there was stronger attraction interaction in the system with MoS 2 + N-CQDs than that with MoS 2 . It can be inferred that the strength and cohesion of the tribofilm formed by MoS 2 + N-CQD nanofluid were more stable and compact [50], contributing to a better lubrication performance. The diffusion of atoms to surface reflects the adsorption behavior with metal atoms [51], and this plays a vital role in chemical reactions and formation of film at the friction interface.…”

A computational and experimental investigation of halloysite silicic surface modifications after alkaline treatment

“…Despite the presence of surface Si−OH groups in Hal is given for granted, very few studies were performed to systematically investigate the possible formation of silanol groups and the structures of the modified silicic layer. In particular, from the computational point of view attention has been devoted mainly to aggregation properties obtained by molecular dynamics simulations (Prishchenko et al, 2018;Pebdani & Miller, 2021), loading characteristics with respect to molecules of interest in applications (Spepi et al, 2016) and molecules adsorption on the two Hal surfaces (Ferrante et al, 2017;Rozza et al, 2019). Some recent studies report the investigation of Hal functionalization with dopants (Zhang et al, 2017) and alkoxysilane groups bearing amine-based ligands (Mehdizadeh et al, 2022) for catalytic purpose, but none of these shed any light on the formation of silanols on the outer surface.…”