scholarly journals Moisture Absorption of Carbon/Epoxy Nanocomposites

2020 ◽  
Vol 4 (1) ◽  
pp. 21 ◽  
Author(s):  
Gorkem E. Guloglu ◽  
M. Cengiz Altan
Keyword(s):  
Carbon Nanomaterials ◽  
Moisture Absorption ◽  
Accurate Determination ◽  
Type Model ◽  
Graphite Nanoplatelets ◽  
Epoxy Nanocomposites ◽  
Thermal Environments ◽  
Thermogravimetric Data ◽  
Hindered Diffusion ◽  
Molecular Bonding

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.

Moisture Effect on Mechanical Properties of Graphene/Epoxy Nanocomposites

2016 ◽  
Vol 32 (6) ◽  
pp. 673-682 ◽  
Author(s):  
H.-K. Liu ◽  
Y.-C. Wang ◽  
T.-H. Huang
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Moisture Absorption ◽  
Graphene Nanosheets ◽  
Salt Water ◽  
Testing Machine ◽  
Weight Fraction ◽  
Epoxy Nanocomposites ◽  
Moisture Effect ◽  
Superior Mechanical Properties

Abstract2-D graphene nanosheets (GNS) not only have superior mechanical properties, but stacking of GNS in composites is expected to inhibit moisture absorption. In this paper, moisture effect on tensile strength of graphene/epoxy nanocomposites is investigated. Two kinds of graphene reinforcements are used including graphene oxide (GO) and reduced graphene oxide (RGO) with reinforcement weight fraction WGO or WRGO in the range of 0.5 to 3.0wt%. A dispersion agent acetone is added in nanocomposites to enhance graphene dispersion. To evaluate moisture influence, those nanocomposites are soaked in two kinds of liquid including deionized water (DIW) and salt water (saline solution) for seven kinds of soaking periods of time including 24, 48, 72, 100, 400 hours, 30 days, and 60 days. After soaking test, diffusion coefficients of various composites are evaluated; besides tensile strengths of composites are measured by microforce testing machine. In order to correlate the strength with microstructure evolution, several techniques are adopted to analyze morphologies and functionalities of reinforcements and fracture surface of composites. They include Raman spectroscope, X-ray photoelectron spectroscope, and SEM. 2-D GNS are found to effectively enhance nanocomposites by moisture attack, and their corresponding reinforcing mechanisms are proposed.

Properties of epoxy nanocomposites filled with carbon nanomaterials

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Young Seok Song ◽  
Jae Ryoun Youn
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Thermal Properties ◽  
Carbon Nanomaterials ◽  
Rheological Behaviour ◽  
Epoxy Composites ◽  
Mechanical And Thermal Properties ◽  
Epoxy Nanocomposites ◽  
Multiwalled Carbon ◽  
Weight Content

Abstract Rheological, mechanical, electrical, and thermal properties of epoxy nanocomposites containing carbon nanomaterials (CNMs) were investigated with different loading. Two kinds of CNMs - multiwalled carbon nanotubes (MWNTs) and carbon blacks (CBs) - were selected to examine the effect of their geometrical structure on various properties. Under sonication, MWNTs and CBs (0.5, 1.0, and 1.5 wt.-%) were mixed with the epoxy resin by using a solvent. Dispersion of the CNMs in the epoxy nanocomposites was characterized by means of transmission electron microscopy and field emission scanning electron microscopy. Carbon nanotubes (CNTs)/epoxy composites show significant differences from the CBs/ epoxy composites due to their high aspect ratio. It was found that the CNTs/epoxy composites exhibit non-Newtonian rheological behaviour, while the CBs/epoxy composites with the same weight content show Newtonian behaviour. The CNTs/ epoxy composites have better mechanical and thermal properties than the CBs/ epoxy composites. In the CNTs nanocomposites, the percolation threshold of electrical conductivity is found to be less than 0.5 wt.-%, which is too low to be obtained by using other carbon materials such as carbon fibre in polymer composites. Effects of CNM content on the various properties were also examined. As loading of the CNMs increased, improved results were obtained.

scholarly journals Mechanistic Insight into Biopolymer Induced Iron Oxide Mineralization Through Quantification of Molecular Bonding

2019 ◽  
Author(s):  
K.K. Sand ◽  
Stanislav Jelavic ◽  
Sören Dobberschütz ◽  
P.D. Ashby ◽  
Matthew J. Marshall ◽  
...  
Keyword(s):  
Density Functional ◽  
Growth Dynamics ◽  
Complex Model ◽  
Nucleation Theory ◽  
Dynamic Force ◽  
Functional Theory ◽  
Thermogravimetric Data ◽  
Water Association ◽  
Molecular Bonding ◽  
Insight Into

Microbial production of iron (oxy)hydroxides on polysaccharide rich biopolymers occurs on such a vast scale that it impacts the global iron cycle and has been responsible for major biogeochemical events. Yet the physiochemical controls these biopolymers exert on iron (oxy)hydroxide formation are poorly understood. Here we used dynamic force spectroscopy to directly probe binding between complex, model and natural microbial polysaccharides and common iron (oxy)hydroxides. Applying nucleation theory to our results demonstrates that if there is a strong attractive interaction between biopolymers and iron (oxy)hydroxides, the biopolymers decrease the nucleation barriers, thus promoting mineral nucleation. These results are also supported by nucleation studies and density functional theory. Spectroscopic and thermogravimetric data provide insight into the subsequent growth dynamics and show that the degree and strength of water association with the polymers can explain the influence on iron (oxy)hydroxide transformation rates. <br>

Structurization and moisture absorption features of epoxy nanocomposites with carbon nanotubes

2015 ◽  
Vol 6 (5) ◽  
pp. 515-520
Author(s):  
P. S. Marakhovskiy ◽  
S. V. Kondrashov ◽  
T. P. Dyachkova ◽  
Ya. M. Gurevich ◽  
I. A. Mayorova ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Moisture Absorption ◽  
Epoxy Nanocomposites ◽  
Absorption Features

scholarly journals Mechanistic Insight into Biopolymer Induced Iron Oxide Mineralization Through Quantification of Molecular Bonding

2019 ◽  
Author(s):  
K.K. Sand ◽  
Stanislav Jelavic ◽  
Sören Dobberschütz ◽  
P.D. Ashby ◽  
Matthew J. Marshall ◽  
...  
Keyword(s):  
Density Functional ◽  
Growth Dynamics ◽  
Complex Model ◽  
Nucleation Theory ◽  
Dynamic Force ◽  
Functional Theory ◽  
Thermogravimetric Data ◽  
Water Association ◽  
Molecular Bonding ◽  
Insight Into

Microbial production of iron (oxy)hydroxides on polysaccharide rich biopolymers occurs on such a vast scale that it impacts the global iron cycle and has been responsible for major biogeochemical events. Yet the physiochemical controls these biopolymers exert on iron (oxy)hydroxide formation are poorly understood. Here we used dynamic force spectroscopy to directly probe binding between complex, model and natural microbial polysaccharides and common iron (oxy)hydroxides. Applying nucleation theory to our results demonstrates that if there is a strong attractive interaction between biopolymers and iron (oxy)hydroxides, the biopolymers decrease the nucleation barriers, thus promoting mineral nucleation. These results are also supported by nucleation studies and density functional theory. Spectroscopic and thermogravimetric data provide insight into the subsequent growth dynamics and show that the degree and strength of water association with the polymers can explain the influence on iron (oxy)hydroxide transformation rates. <br>

Dispersion technology on mechanical properties of carbon nanomaterials reinforced epoxy nanocomposites

2020 ◽  
Vol 34 (07n09) ◽  
pp. 2040019
Author(s):  
Chin-Lung Chiang ◽  
Chien-Wei Hsu ◽  
Hsiu-Ming Wu ◽  
Ming-Yuan Shen
Keyword(s):  
Mechanical Properties ◽  
Contact Area ◽  
Carbon Nanomaterials ◽  
Flexural Modulus ◽  
Stress Transfer ◽  
Phonon Transport ◽  
Epoxy Nanocomposites ◽  
Constant Area ◽  
Surface Contact Area ◽  
Scanning Electron

Graphene nanoplatelets (GNPs) are platelet-liked graphite nanocrystals with multigraphene layers. In general, a high contact area between polymer and nanofiller maximizes stress transfer from the polymer matrix to nanofillers. Therefore, GNPs can be expected to exhibit better reinforcement than CNTs in polymer composites, because of their ultrahigh aspect ratio (600–10,000) and higher surface constant area. The GNPs planar structure provides a 2D path for phonon transport, and the ultrahigh surface area allows a large surface contact area with polymer resulting in the enhancement of the composite thermal conductivity. In this study, simple and efficient planetary mixing methods were used to enable the GNPs to disperse uniformly throughout the epoxy solution (i.e. 0, 0.1, 0.25, 0.5, 0.75, and 1.0 wt%) and then to prepare GNPs/epoxy nanocomposites. Mechanical properties of the nanocomposite, including ultimate tensile, flexural strength and flexural modulus, were investigated. Finally, the fracture surface of the specimen was investigated using scanning electron microscopy (SEM) to determine the dispersion of the GNPs in the composites.

Sign in / Sign up

Export Citation Format

Share Document