Finite Element Analysis of Gas Diffusion in Polymer Nanocomposite Systems Containing Rod-like Nanofillers

Abstract

Polymer-based films with improved gas barrier properties are of great interest for a large range of applications, including packaging and coatings. The barrier effect is generally obtained via the addition of a sufficient amount of impermeable nanofillers within the polymer matrix. Due to their low environmental footprint, bio-based nanocomposites such as poly(lactic acid)–cellulose nanocrystal (PLA–CNC) nanocomposites seem to be an interesting alternative to synthetic-polymer-based nanocomposites. The morphology of such systems consists of the dispersion of impermeable rod-like fillers of finite length in a more permeable matrix. The aim of this work is to analyze, through finite element modeling (FEM), the diffusion behavior of 3D systems representative of PLA–CNC nanocomposites, allowing the determination of the nanocomposites’ effective diffusivity. Parametric studies are carried out to evaluate the effects of various parameters, such as the filler volume fraction, aspect ratio, polydispersity, and agglomeration, on the improvement of the barrier properties. The role of the filler–matrix interfacial area (or interphase) is also investigated and is shown to be particularly critical to the overall barrier effect for highly diffusive interphases.

Dispersibility Characterization of Cellulose Nanocrystals in Polymeric-Based Composites

“…126,232 As shown in Figure 21, Htira et al analyzed the permeation behavior of PLA-CNC composites by finite element modeling and discussed the permeation mechanism in-depth. 238…”

“…Diffusion mechanism model and finite element modeling of rod-shaped nanoparticle composites. Reproduced with permission from ref . MDPI 2021 under CC BY 4.0 ().…”

“…All three points require good dispersibility of the CNC in the matrix. With the increase in the CNC content, the value of the WVP remains constant or increases, which is attributed to the fact that the CNC generates agglomerates that provide channels or regions in the material to create preferential penetrate pathways and decrease the effective diffusion path length. , As shown in Figure , Htira et al analyzed the permeation behavior of PLA-CNC composites by finite element modeling and discussed the permeation mechanism in-depth …”