Effect of amino acid-functionalization on the interfacial adhesion and behavior of multi-walled carbon nanotubes/poly(amide-imide) nanocomposites containing thiazole side unit

2013 ◽  
Vol 20 (7) ◽  
Author(s):  
Shadpour Mallakpour ◽  
Amin Zadehnazari
Keyword(s):  
Carbon Nanotubes ◽  
Amino Acid ◽  
Interfacial Adhesion ◽  
Multi Walled Carbon Nanotubes ◽  
And Behavior ◽  
Walled Carbon Nanotubes

Static and Fatigue Strengths of Carbon Nanotube/Epoxy Composites under Hygrothermal Environments

2013 ◽  
Vol 284-287 ◽  
pp. 204-210
Author(s):  
Yi Ming Jen ◽  
Chien Yang Huang
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Stress Concentration ◽  
Interfacial Adhesion ◽  
Epoxy Composites ◽  
Hygrothermal Effect ◽  
Multi Walled Carbon Nanotubes ◽  
Hygrothermal Environments ◽  
Stress Concentration Effect ◽  
Walled Carbon Nanotubes

This study experimentally analyzed the hygrothermal effect on the static and fatigue strengths of acid-treated multi-walled carbon nanotubes (CNTs)/epoxy composites. The nanocomposite specimens with various CNT contents (0., 0.5, and 1.0 wt.%) were statically and fatigue-tested under three different hygrothermal conditions (25 °C/60% RH, 25° C/85% RH, and 40 °C/85% RH) to investigate the influences of hygrothermal conditions and CNT contents on the tensile static and fatigue strengths of the studied nanocomposites. The results show that the static and fatigue strengths decreased slightly at 25 °C/85% RH environments compared with those tested under the 25 °C/60% RH condition. However, the static and fatigue strengths of the studied nanocomposites decreased substantially under the 40 °C/85% RH condition. The combined temperature and humidity environments weaken the interfacial adhesion between the CNT surfaces and the epoxy matrix. Moreover, the experimental results show that the addition of 0.5 wt.% of carbon nanotubes improved the static and fatigue strengths considerably under the same hygrothermal environments. However, when an excessive amount of CNTs was used (1.0 wt.%), the nanocomposite exhibited the lowest strengths compared with the specimens with 0 and 0.5 wt.% CNTs. The stress concentration effect caused by the CNT aggregates was detrimental to the static and fatigue strengths of the studied nanocomposites.

Thermo-mechanical properties of epoxy nanocomposites incorporating amino acid and acid functionalized multi-walled carbon nanotubes

2019 ◽  
Vol 54 (14) ◽  
pp. 1847-1861
Author(s):  
Alireza Bagherzade ◽  
Masoud Jamshidi
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Amino Acid ◽  
Epoxy Resin ◽  
Acid Treatment ◽  
Curing Temperature ◽  
Gravimetric Analysis ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Functionalized Mwcnts

In this study, multi-walled carbon nanotubes (MWCNTs) were functionalized by both sulfuric/nitric acids and amino acids to form COOH and NH2/COOH/OH groups on their surface, respectively. The functionalized MWCNTs were characterized by Fourier Transform Infrared Spectroscopy, titration test, thermal gravimetric analysis, and solvent stability test. The results revealed that in each method, the functional groups were successfully attached to the surface of nanotubes. Acid treatment grafted more oxygen-containing groups compared to commercial carboxylated MWCNTs. The amino acid functionalized MWCNTs indicated improved stability in different solvents compared to raw and acid treated MWCNTs. These functionalized MWCNTs were incorporated into epoxy resin and the properties of the nanocomposites were evaluated by scanning electron microscopy, tensile test, dynamic mechanical thermal analysis, differential scanning calorimetry, and thermogravimetric analysis. The morphology of the nanocomposites revealed that acid and amino acid treated samples had better interaction with the epoxy resin. Compared to epoxy sample contained raw MWCNT (control) and commercial carboxylated MWCNTs, the addition of functionalized MWCNTs to the epoxy resin improved the tensile strength by 39% and 25% (for acid treated) and 46% and 33% (for amino acid treated), respectively. The best tensile properties for acid and amino acid treated samples were reached by MWCNTs acid treated at 110℃ for 15 min and MWCNTs treated in a 50 g/L aqueous solution of amino acid, respectively. Storage modulus of the epoxy samples which contained acid and amino acid treated MWCNTs were 1560 and 1900 MPa, respectively. The glass rubber transition temperature ( Tg) of the epoxy samples containing acid and amino acid treated nanotubes were increased by 1.1℃ and 5.9℃, respectively, compared to the control sample. Therefore, based on these mechanical properties, the epoxy samples containing nanotubes functionalized by amino acid exhibited the highest performance in the epoxy nanocomposite. Incorporating acid and amino acid treated MWCNTs accelerated the curing process of epoxy where the curing temperature decreased by 9.1℃ and 13.3℃, respectively. Because of the reaction between amine groups grafted on MWCNTs in the amino acid treatment and epoxide groups of the epoxy resin, this acceleration was more significant in the case of amino acid sample. Note that addition of functionalized MWCNTs to epoxy resin did not lead to increased thermal stability.

Enhanced Thermal Conductivity of Nanofluid by Synergistic Effect of Multi-Walled Carbon Nanotubes and Fe2O3 Nanoparticles

2014 ◽  
Vol 548-549 ◽  
pp. 118-123 ◽  
Author(s):  
Li Fei Chen ◽  
Min Cheng ◽  
De Jun Yang ◽  
Lei Yang
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Synergistic Effect ◽  
Interfacial Adhesion ◽  
Conductivity Enhancement ◽  
Hybrid Fillers ◽  
Water Based ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Enhanced Thermal Conductivity

This study investigates the synergistic effect of combining multi-walled carbon nanotubes (MWNTs) and Fe2O3nanoparticles on thermal conductivity of nanofluid. Results show that low percentage hybrid fillers loading improve thermal conductivity of water based nanofluid, due to the good dispersion and interfacial adhesion, which is confirmed by scanning electron microscope. Furthermore, the hybrid fillers provide synergistic effect on heat conductive networks. The thermal conductivity enhancement of water based nanofluid containing 0.05 wt % MWNTs and 0.02 wt % Fe2O3nanoparticles is 27.75%, which is higher than that of nanofluid containing 0.2 wt % single MWNTs or Fe2O3nanoparticles.

scholarly journals A Novel Method for Deposition of Multi-Walled Carbon Nanotubes onto Poly(p-Phenylene Terephthalamide) Fibers to Enhance Interfacial Adhesion with Rubber Matrix

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 374 ◽  
Author(s):  
Xuan Yang ◽  
Qunzhang Tu ◽  
Xinmin Shen ◽  
Pengxiao Zhu ◽  
Yi Li ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Interfacial Adhesion ◽  
Polar Solvent ◽  
Contact Angles ◽  
Rubber Matrix ◽  
Chemical Structures ◽  
Multi Walled Carbon Nanotubes ◽  
Novel Method ◽  
Walled Carbon Nanotubes ◽  
Epoxy Groups

In order to enhance the interfacial adhesion of poly(p-phenylene terephthalamide) (PPTA) fibers to the rubber composites, a novel method to deposit multi-walled carbon nanotubes (MWCNTs) onto the surface of PPTA fibers has been proposed in this study. This chemical modification was performed through the introduction of epoxy groups by Friedel–Crafts alkylation on the PPTA fibers, the carboxylation of MWCNTs, and the ring-opening reaction between the epoxy groups and the carboxyl groups. The morphologies, chemical structures, and compositions of the surface of PPTA fibers were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results showed that MWCNTs were uniformly deposited onto the surface of PPTA fibers with the covalent bonds. The measurement of contact angles of the fibers with polar solvent and non-polar solvent indicated that the surface energy of deposited fibers significantly increased by 41.9% compared with the untreated fibers. An electronic tensile tester of single-filament and a universal testing machine were utilized to measure the strength change of the fibers after modification and the interfacial adhesion between the fibers and the rubber matrix, respectively. The results showed that the tensile strength had not been obviously reduced, and the pull-out force and peeling strength of the fibers to the rubber increased by 46.3% and 56.5%, respectively.

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