Moisture Absorption of Carbon/Epoxy Nanocomposites

Abstract

Moisture absorption of composites with nanoscale carbon additives such as carbon nanotubes, carbon nanofibers, graphite nanoplatelets, and carbon black is investigated using thermogravimetric data and a non-Fickian hindered diffusion (Langmuir-type) model. The moisture absorption parameters are determined using this model for six different types of carbon/epoxy nanocomposites. The absorption behaviors obtained at different humidity levels and thermal environments are recovered by minimizing the error between the experimental data and model predictions, thus enabling the accurate determination of the moisture equilibrium level. The absorption behavior and the weight gain of all nanocomposites are shown to be accurately represented by this model over the entire absorption period. The presence of carbon nanomaterials is found to induce varying levels of non-Fickian behavior, governed by the nondimensional hindrance coefficient. This behavior is enhanced with the nanomaterial content and separate from the slight non-Fickian behavior of all neat epoxy samples. The molecular bonding during diffusion, as well as the interfacial moisture storage, could be among the reasons for non-Fickian behavior and should be included in the absorption models for accurate characterization of carbon/epoxy nanocomposites.

Physicomechanical Properties of Rice Husk/Coco Peat Reinforced Acrylonitrile Butadiene Styrene Blend Composites

“…It was claimed that these biocomposites were in an intermediate diffusion process between the penetrant mobility cases I and II. However, Guloglu et al [ 21 ] mentioned that most composites structures were in a range of abnormal water diffusion characteristics. This typical non-Fickian moisture absorption behavior of the thermoplastic-based composites was also reported by Melo et al [ 22 ] and Aziz et al [ 23 ] when the samples were continually exposed to a wet environment at a lower absorption rate and prolonged period.…”

On the relationship between moisture uptake and mechanical property changes in a carbon fibre/epoxy composite

“…Values for M 1 , β, γ , and subsequently the hindrance coefficient, µ , were calculated also as in. 37…”

“…This approach has been successfully used to describe the diffusion behaviour of various polymeric materials 31,36,37 and composite systems. 25,30,36,37…”

“…To calculate these diffusion parameters, the method proposed by Carter, 31 and further described by Joliff et al 25 or Guloglu et al 37 may be used.…”

Modelling of Environmental Ageing of Polymers and Polymer Composites—Modular and Multiscale Methods

“…This behaviour is known as non-Fickian diffusion. Degradation [ 13 , 50 , 51 , 67 ], molecular relaxation [ 75 , 76 ] and specific interactions between the polar sites of the host polymer and a penetrant [ 77 , 78 , 79 , 80 ] are among the main factors contributing to the anomalous water absorption.…”