A computer simulation of stress transfer in carbon nanotube/polymer nanocomposites

Abstract

The reinforcing efficiency or stress transfer of carbon nanotubes (CNT) on polymers in polymer/CNT composites mainly is controlled by the polymer-CNT interface. Enhancement of polymer-CNT interactions and interfacial crystallisation is as an important way for improvement of the reinforcement experimentally. However, it is not clear about the crystallisation and orientation of polymer chains on the CNT surface, and how the interfacial crystallisation layer affects the failure of the composite. In this work, poly(vinyl alcohol)/CNT nanocomposites was selected as an example and based on the molecular dynamics simulation, the crystallisation process, failure behaviour and stress transfer in poly(vinyl alcohol)/CNT nanocomposites were analysed. The crystallisation temperature of the polymer chains on the CNT surface is slightly higher than the bulk crystallisation temperature. CNT induced crystallisation can be divided into three stages: chain folding, orientating and growing on the CNT surface. A slower crack growth was observed in the interfacial crystallised polymer/CNT systems, compare to relative amorphous systems. The effect of the interfacial crystalline layer on stress transfer is similar as enhanced polymer-CNT interaction systems. The change of the polymer-CNT surficial energy to strain has been used to analyse the interfacial failure and the stress transfer.

Molecular dynamics simulation and non-isothermal crystallization kinetics of polyamide 4 and different bio-based polyamide blends

“…As the components of the PA/PA blends were identical (i.e., the same functional groups were present), studying their phases and crystallization behaviors was more challenging. However, with the continuous development of computing power, molecular dynamics (MD) simulations began to play crucial roles in material modeling, 21 understanding the crystallization mechanisms, [22][23][24] and phase-behavior analysis. [25][26][27][28] MD simulations are also critical in microstructural analysis.…”

Crystallization and Performance of Polyamide Blends Comprising Polyamide 4, Polyamide 6, and Their Copolymers

“…On the other hand, PAs contain the same functional groups, which makes it difficult to distinguish the different molecular chains in PA/PA blends and limits microstructural observations. Molecular dynamics (MD) simulations therefore play a crucial role in microstructural analysis [ 22 ], understanding the crystallization mechanisms [ 23 , 24 , 25 ] and hydrogen bonding-induced phase changes in polymer blends [ 26 ].…”

Ionizing Radiation Sensing with Functionalized and Copper-Coated SWCNT/PMMA Thin Film Nanocomposites

“…Another example of synthesis of NiFe films using direct, pulse, and pulse-reverse electrodeposition modes studied the deposit composition, crystal structure, and surface microstructure [18]. There has been mechanical modeling of thin films [19,20], PMMA [21] and a polymer/carbon nanotube [22]. The experimental thermomechanical property was studied on materials such as ceramics [23], PMMA/SWCNT interfaces [24], and PMMA and modified SWCNT [25].…”