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 Temperature-Dependent Synergistic Effect of Multi-Walled Carbon Nanotubes and Graphene Nanoplatelets on the Tensile Quasi-Static and Fatigue Properties of Epoxy Nanocomposites

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 84
Author(s):  
Yi-Ming Jen ◽  
Hao-Huai Chang ◽  
Chien-Min Lu ◽  
Shin-Yu Liang
Keyword(s):  
Carbon Nanotubes ◽  
Fatigue Strength ◽  
Synergistic Effect ◽  
Polymer Nanocomposites ◽  
Graphene Nanoplatelets ◽  
Temperature Dependent ◽  
Epoxy Nanocomposites ◽  
Hybrid Fillers ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Even though the characteristics of polymer materials are sensitive to temperature, the mechanical properties of polymer nanocomposites have rarely been studied before, especially for the fatigue behavior of hybrid polymer nanocomposites. Hence, the tensile quasi-static and fatigue tests for the epoxy nanocomposites reinforced with multi-walled carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) were performed at different temperatures in the study to investigate the temperature-dependent synergistic effect of hybrid nano-fillers on the studied properties. The temperature and the filler ratio were the main variables considered in the experimental program. A synergistic index was employed to quantify and evaluate the synergistic effect of hybrid fillers on the studied properties. Experimental results show that both the monotonic and fatigue strength decrease with increasing temperature significantly. The nanocomposites with a MWCNT (multi-walled CNT): GNP ratio of 9:1 display higher monotonic modulus/strength and fatigue strength than those with other filler ratios. The tensile strengths of the nanocomposite specimens with a MWCNT:GNP ratio of 9:1 are 10.0, 5.5, 12.9, 23.4, and 58.9% higher than those of neat epoxy at −28, 2, 22, 52, and 82 °C, respectively. The endurance limits of the nanocomposites with this specific filler ratio are increased by 7.7, 26.7, 5.6, 30.6, and 42.4% from those of pristine epoxy under the identical temperature conditions, respectively. Furthermore, the synergistic effect for this optimal nanocomposite increases with temperature. The CNTs bridge the adjacent GNPs to constitute the 3-D network of nano-filler and prevent the agglomeration of GNPs, further improve the studied strength. Observing the fracture surfaces reveals that crack deflect effect and the bridging effect of nano-fillers are the main reinforcement mechanisms to improve the studied properties. The pullout of nano-fillers from polymer matrix at high temperatures reduces the monotonic and fatigue strengths. However, high temperature is beneficial to the synergistic effect of hybrid fillers because the nano-fillers dispersed in the softened matrix are easy to align toward the directions favorable to load transfer.

Thermal Conductivity Measurement for Carbon-Nanotube Suspensions with 3ω Method

2009 ◽  
Vol 60-61 ◽  
pp. 394-398 ◽  
Author(s):  
Gen Sheng Wu ◽  
Jue Kuan Yang ◽  
Shu Lin Ge ◽  
Yu Juan Wang ◽  
Min Hua Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Volume Fraction ◽  
Aqueous Suspension ◽  
Conductivity Measurement ◽  
3Ω Method ◽  
Conductivity Enhancement ◽  
Multi Walled Carbon Nanotubes ◽  
The Stability ◽  
Walled Carbon Nanotubes

The stable and homogeneneous aqueous suspension of carbon nanotubes was prepared in this study. The stability of the nanofluids was improved greatly due to the use of a new dispersant, humic acid. The thermal conductivity of the aqueous suspension was measured with the 3ω method. The experimental results showed that the thermal conductivity of the suspensions increases with the temperature and also is nearly proportional to the loading of the nanoparticles. The thermal conductivity enhancement of single-walled carbon nanotubes (SWNTs) suspensions is better than that of the multi-walled carbon nanotubes (MWNTs) suspensions. Especially for a volume fraction of 0.3846% SWNTs, the thermal conductivity is enhanced by 40.5%. Furthermore, the results at 30°C match well with Jang and Choi’s model.

scholarly journals Thermophysical Properties of IoNanofluids Composed of 1-ethyl-3-methylimidazolium Thiocyanate and Carboxyl-functionalized Long Multi-walled Carbon Nanotubes

Fluids ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 214
Author(s):  
Bertrand Jóźwiak ◽  
Justyna Dziadosz ◽  
Adrian Golba ◽  
Krzysztof Cwynar ◽  
Grzegorz Dzido ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carboxylic Group ◽  
Conductivity Enhancement ◽  
Multi Walled Carbon Nanotubes ◽  
Vibrating Tube Densimeter ◽  
Carbon Based Nanomaterials ◽  
Walled Carbon Nanotubes ◽  
Rotary Viscometer

The concept of IoNanofluids (INFs) as the stable dispersions of nanoparticles in ionic liquids was proposed in 2009 by Nieto de Castro’s group. INFs characterize exciting properties such as improved thermal conductivity, non-volatility, and non-flammability. This work is a continuation of our studies on the morphology and physicochemistry of carbon-based nanomaterials affecting thermal conductivity, viscosity, and density of INFs. We focus on the characterization of dispersions composed of long carboxylic group-functionalized multi-walled carbon nanotubes and 1-ethyl-3-methylimidazolium thiocyanate. The thermal conductivity of INFs was measured using KD2 Pro Thermal Properties Analyzer (Decagon Devices Inc., Pullman, WA, USA). The viscosity was investigated using rotary viscometer LV DV-II+Pro (Brookfield Engineering, Middleboro, MA, USA). The density of INFs was measured using a vibrating tube densimeter Anton Paar DMA 5000 (Graz, Austria). The maximum thermal conductivity enhancement of 22% was observed for INF composed of 1 wt% long carboxylic group-functionalized multi-walled carbon nanotubes.

Polyimide nanocomposites with boron nitride-coated multi-walled carbon nanotubes for enhanced thermal conductivity and electrical insulation

2014 ◽  
Vol 2 (48) ◽  
pp. 20958-20965 ◽  
Author(s):  
Wei Yan ◽  
Yi Zhang ◽  
Huawei Sun ◽  
Siwei Liu ◽  
Zhenguo Chi ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Boron Nitride ◽  
Electrical Insulation ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Enhanced Thermal Conductivity

Polyimide nanocomposites with boron nitride-coated multi-walled carbon nanotubes (BN-c-MWCNTs) were successfully prepared with enhanced thermal conductivity and electrical insulation.

Water Based Multiwalled Carbon Nanotube Nanofluids With Optimized Thermal Conductivity

2009 ◽  
Author(s):  
Li Fei Chen ◽  
Huaqing Xie ◽  
Wei Yu ◽  
Yang Li
Keyword(s):  
Thermal Conductivity ◽  
Ball Milling ◽  
Volume Fraction ◽  
Free Water ◽  
Strong Acid ◽  
Multiwalled Carbon ◽  
Conductivity Enhancement ◽  
Water Based ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

We report a method to prepare surfactant-free water based nanofluids containing multi-walled carbon nanotubes (CNTs). The as prepared CNTs with hard dispersibility, after being cut by mechanical ball-milling approach following strong acid treatment, can be directly dispersed into water. The thermal conductivity of the nanofluids is optimized by controlling the CNT length and straightness. It is realized by changed the ball-milling times. The thermal conductivity enhancement of water based CNT nanofluids with volume fraction of 1% attains 29.5% by controlling the CNT length and straightness when the temperature is 63.9°C.

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