scholarly journals Positioning and aligning CNTs by external magnetic field to assist localised epoxy cure

Open Physics ◽  
2016 ◽  
Vol 14 (1) ◽  
pp. 508-516 ◽  
Author(s):  
G. Ariu ◽  
I. Hamerton ◽  
D. Ivanov
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Induction Heating ◽  
Cure Kinetics ◽  
Proof Of Concept ◽  
Suitable Candidate ◽  
Network Geometry ◽  
Multi Walled Carbon Nanotubes ◽  
Resin Curing ◽  
Walled Carbon Nanotubes

AbstractThis work focuses on the generation of conductive networks through the localised alignment of nano fillers, such as multi-walled carbon nanotubes (MWCNTs). The feasibility of alignment and positioning of functionalised MWCNTs by external DC magnetic fields was investigated. The aim of this manipulation is to enhance resin curing through AC induction heating due to hysteresis losses from the nanotubes. Experimental analyses focused on in-depth assessment of the nanotube functionalisation, processing and characterisation of magnetic, rheological and cure kinetics properties of the MWCNT solution. The study has shown that an external magnetic field has great potential for positioning and alignment of CNTs. The study demonstrated potential for creating well-ordered architectures with an unprecedented level of control of network geometry. Magnetic characterisation indicated cobalt-plated nanotubes to be the most suitable candidate for magnetic alignment due to their high magnetic sensitivity. Epoxy/metal-plated CNT nanocomposite systems were validated by thermal analysis as induction heating mediums. The curing process could therefore be optimised by the use of dielectric resins. This study offers a first step towards the proof of concept of this technique as a novel repair technology.

Cure and Dynamic-Mechanical Behaviors of Vinyl Ester Resinfilled with Multi-Walled Carbon Nanotubes

2010 ◽  
Vol 150-151 ◽  
pp. 1413-1416 ◽  
Author(s):  
Hong Yan Chen ◽  
Zhen Xing Kong ◽  
Ji Hui Wang
Keyword(s):  
Carbon Nanotubes ◽  
Vinyl Ester ◽  
Mechanical Response ◽  
Cure Kinetics ◽  
Crosslinking Density ◽  
Vinyl Ester Resin ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The cure kinetics of Derakane 411-350, a kind of vinyl ester resin, and its suspensions containing multi-walled carbon nanotubes( MWCNTs) were investigated via non-isothermal dynamic scanning calorimetry (DSC) measurements. The results showed that incorporation of MWCNTs into vinyl ester resin excessively reduces polymerization degree and crosslinking density of vinyl ester resin. For suppressing the negative effect caused by nanotubes, the higher temperature initiator combined with the initiator MEKP was used. Dynamic-mechanical Behavior testing was then carried out on the cured sample in order to relate the curing behavior of MWCNTs modified resin suspensions to mechanical response of their resulting nanocomposites. It was revealed that nanocomposites containing MWCNTs possessed larger storage modulus values as well as higher glass transition temperatures (Tg) as compared to those without MWCNTs after using mixed intiators system to improve the degree of cure.

scholarly journals Structure and electrical conductivity of polyvinyl alcohol films with multi-walled carbon nanotubes, cured in a magnetic field

2021 ◽  
Vol 13 (4) ◽  
pp. 457-464
Author(s):  
Sergey V. Vasin ◽  
◽  
Azat M. Nizametdinov ◽  
Viacheslav A. Sergeev ◽  
Michael S. Efimov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Polyvinyl Alcohol ◽  
Nanocomposite Films ◽  
Polymerization Process ◽  
Degree Of Orientation ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Control Samples

The results of the study of the effect of the permanent magnetic field of a neodymium magnet on the polymerization process and the electrophysical characteristics of polyvinyl alcohol (PVA) films with the inclusion of multi-walled carbon nanotubes (MWCNTs) are presented. When studying the morphology of films using a scanning electron microscope, it was found that nanocomposite films with a thickness of 30 microns, cured in the presence of a magnetic field with the direction of the magnetic induction vector perpendicular to the surface of the films, have a homogeneous structure, while a significant number of MWCNTs agglomerations are observed in control samples of films. Measurements of the conductivity of films in the direction of the MWCNTs orientation at direct and alternating current showed that the conductivity of films obtained in a magnetic field significantly (by almost two orders of magnitude) exceeds the conductivity of control samples. The obtained results are analyzed on the basis of known models of electrical conductivity of nanocomposites with oriented MWCNTs. The degree of orientation of the MWCNTs during the curing of films in a magnetic field is estimated, taking into account the increase in the viscosity of the nanocomposite during the curing process.

Fabrication of Magnetic Polymer Composite Sorbents and its Application for Recovery of Platinum from Acidic Solution

2017 ◽  
Vol 262 ◽  
pp. 311-314
Author(s):  
Myung Hee Song ◽  
D. Harikishore Kumar Reddy ◽  
John Kwame Bediako ◽  
Shuo Lin ◽  
Yeoung Sang Yun
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Polymer Composite ◽  
Acidic Solution ◽  
Sorption Process ◽  
Composite Sorbents ◽  
Multi Walled Carbon Nanotubes ◽  
Adsorptive Recovery ◽  
Walled Carbon Nanotubes

Magnetic MnFe2O4 nanoparticles (MNPs) were fabricated and entrapped in amine-rich chitosan (CS) sorbents containing multi-walled carbon nanotubes (MWCNTs) or polyethyleneimine (PEI). Magnetic polymer composite sponges (MPCSs) and magnetic polymer composite fibers (MPCFs) were prepared through mixing each of MWCNT and PEI with MNPs-CS solution. The successful fabrication of MPCSs and MPCFs was confirmed through FTIR and VSM analyses. The as-fabricated MPCSs and MPCFs were used for adsorptive recovery of Pt (IV) from acidic solution. The maximum uptakes of Pt (IV) ions by the MPCSs and MPCFs were estimated to be 218.2 ± 8.3 and 371.4 ± 16.8 mg/g, respectively. Moreover, the Pt (IV)-loaded MPCSs and MPCFs were easily separated from aqueous solution under magnetic field after sorption process.

scholarly journals Enhanced Detection Systems of Filling Rates Using Carbon Nanotube Cement Grout

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 10 ◽  
Author(s):  
Heeyoung Lee ◽  
Seonghoon Park ◽  
Sanggyu Park ◽  
Wonseok Chung
Keyword(s):  
Magnetic Field ◽  
Carbon Nanotubes ◽  
Field Tests ◽  
Cement Grout ◽  
Filling Rate ◽  
Cross Sectional ◽  
Detection Systems ◽  
Void Detection ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The addition of small amounts of carbon nanotubes (CNTs) to cement-based materials modifies their thermal and electrical characteristics. This study investigated the void detection and filling rates of cement grout with multi-walled carbon nanotubes (MWCNTs). MWCNT grouts of 40 mm × 40 mm × 160 mm were fabricated. Specimens were tested by thermal imaging, electrical resistance analyses, and magnetic field tests. The experimental parameters were the concentration of MWCNT and the grout filling rate. The filling rate was investigated by measuring resistance and magnetic field changes with respect to cross-sectional area, taking the voids into consideration. The results of the thermal image tests indicate that 1.0 wt % MWCNT cement grout is optimal for void detection.

Improving the mechanical properties of Fe3O4/carbon nanotube reinforced nanocomposites by a low-magnetic-field induced alignment

2018 ◽  
Vol 38 (8) ◽  
pp. 731-738
Author(s):  
Yifan Huang ◽  
Weicheng Jiao ◽  
Yue Niu ◽  
Guomin Ding ◽  
Rongguo Wang
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Field Strength ◽  
Polymer Matrix ◽  
Inert Gas ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Low Magnetic Field

Abstract The aim of the paper is to develop a novel nanocomposite with high mechanical properties. The mechanical properties are improved by aligning the Fe3O4/multi-walled carbon nanotubes (MWCNTs) into a highly oriented manner in epoxy resin (EP) via a low magnetic field. Fe3O4 nanoparticles were tethered onto the surface of MWCNTs by a novel water-in-oil (W/O) method without heating at high temperatures or the protection of inert gas. Then, the modified magnetic MWCNTs (m-MWCNTs) were added into EP and aligned in a low magnetic field (100 mT). A method was presented to estimate the minimum magnetic field strength for aligning the m-MWCNTs. Besides, the morphology and microstructures of the fabricated m-MWCNTs and m-MWCNTs/EP highly ordered nanocomposites were characterized. Finally, the mechanical properties measurements were performed. The results of the experiments showed that this method was very efficient in aligning m-MWCNTs embedded in polymer matrix leading to a highly ordered composite for improving mechanical properties.

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