Polystyrene adsorbed multi-walled carbon nanotubes incorporated polymethylmethacrylate composites with modified percolation phenomena

MRS Advances ◽  
2017 ◽  
Vol 3 (1-2) ◽  
pp. 25-30
Author(s):  
Tajamal Hussain ◽  
Tayyaba Malik ◽  
Adnan Mujahid ◽  
Ghulam Mustafa
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Properties ◽  
Percolation Threshold ◽  
Ftir Spectroscopy ◽  
Electrical Parameters ◽  
Dispersion Process ◽  
Multi Walled Carbon Nanotubes ◽  
Percolation Phenomena ◽  
Lcr Meter ◽  
Walled Carbon Nanotubes

ABSTRACTExtensive work has been done on the modification of multi-walled carbon nanotubes (MWCNTs) to improve their characteristics. Here, polystyrene (PS) was adsorbed on the surface of MWCNTs by dispersion process, using toluene as medium. PS modified MWCNTs (PS-MWCNTs) have been dispersed in polymethylmethacrylate (PMMA) matrix to prepare composite, PS-MWCNTs/PMMA. It is expected that PS adsorbed at the surface of the MWCNTs will help in improving the interaction between MWCNTs and PMMA which results uniform and homogeneous dispersion of the former in later. Thus, synthesized composites were characterized by UV-Vis and FTIR spectroscopy to monitor the functionality of developed product. Electrical parameters including conductivity and dielectric properties were measured with the help of LCR meter. Electrical characters of the composites were explored by investigating the effect of contents of PS-MWCNTs on conductivity and dielectric properties. Percolation behaviour was examined and calculated value of percolation threshold was 0.1wt%.

Dielectric and Thermomechanical Properties of Polypropylene/Multi-Walled Carbon Nanotubes Nanocomposites

2007 ◽  
Vol 1056 ◽  
Author(s):  
A. Kanapitsas ◽  
E. Logakis ◽  
C. Pandis ◽  
I. Zuburtikudis ◽  
P. Pissis ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Percolation Threshold ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Dielectric Relaxation Spectroscopy ◽  
Melt Mixing ◽  
Polypropylene Nanocomposites ◽  
Multi Walled Carbon Nanotubes ◽  
Permittivity Measurements ◽  
Walled Carbon Nanotubes

ABSTRACTThe purpose of this work is to examine the dielectric, electrical and thermo-mechanical properties of multi-walled carbon nanotubes (MWCNT) filled polypropylene nanocomposites formed by melt-mixing. To that aim dielectric relaxation spectroscopy (DRS) and dymamic mechanical analysis (DTMA) were employed. The results are discussed in terms of nucleating action of MWCNT and interfacial polymer-filler interactions. Special attention is paid to percolation aspects by both ac conductivity measurements for the samples which are above the percolation threshold and permittivity measurements for the samples which are below percolation threshold.

Selective Dispersion of Multi-Walled Carbon Nanotubes in Segmented Polyurethane with Different Melt Mixing Process

2017 ◽  
Vol 730 ◽  
pp. 237-241
Author(s):  
Kittimon Jirakittidul ◽  
Krittaya Khrongsakun ◽  
Kannika Khongkhaw ◽  
Kusuman Nernplod
Keyword(s):  
Carbon Nanotubes ◽  
Soft Segment ◽  
Mixing Time ◽  
Melt Mixing ◽  
Segmented Polyurethane ◽  
Soft Segments ◽  
Multi Walled Carbon Nanotubes ◽  
Lcr Meter ◽  
Internal Mixer ◽  
Walled Carbon Nanotubes

Polyurethanes (PU) have been widely used in many applications since their properties can be tailored as desire. In order to improve their electrical property, PU is incorporated with multi-walled carbon nanotubes (MWCNT). The effects of different mixing times and temperatures on selective dispersion of MWCNT in segmented PU were studied. Furthermore, segmented PU based on two different soft segments; i.e. polyester (PU-ester) and polyether (PU-ether), were used. PU/MWCNT nanocomposites were prepared by an internal mixer for 4-12 minutes at 190-210°C. FESEM, DSC and LCR meter were used to characterize morphology and thermal properties. It was found that MWCNT were dispersed in soft segment of PU-ether. Good MWCNT dispersion was able to achieve at high temperature with short mixing time or low temperature with long mixing time. On the other hand, PU-ester/MWCNT nanocomposites, MWCNT preferred to disperse in hard segment and could be dispersed well in PU-ester at low mixing temperature.

Study on Dielectric and Magnetic Properties of MWCNTs/Polyester Composites

2015 ◽  
Vol 815 ◽  
pp. 188-192
Author(s):  
Y.S. Lee ◽  
F. Malek ◽  
E.M. Cheng ◽  
Wei Wen Liu ◽  
Kok Yeow You ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Magnetic Properties ◽  
Dielectric Properties ◽  
Rectangular Waveguide ◽  
The Real ◽  
Multi Walled Carbon Nanotubes ◽  
Polyester Composites ◽  
Walled Carbon Nanotubes ◽  
Ku Band ◽  
Dielectric Conductivity

This paper is to study the dielectric properties, magnetic properties, and dielectric conductivity of Multi-walled carbon nanotubes (MWCNTs) and polyester (PE) composites. The composites with different amount of MWCNTs (5-15%) have been studied in the Ku-Band range (12.4-18 GHz). The rectangular waveguide (WR-62) was used to measure the dielectric properties and magnetic properties of the samples. The results show the dielectric properties and conductivity of MWCNTs/PE composites is increasing with the MWCNTs filler increases. The real part of dielectric properties values increase from 5.5 to 26.6 with increasing the MWCNTs loading from 5 % to 15 %. The increasing of MWCNTs filler in the MWCNTs/PE composites does not effects on magnetic properties, the real part and imaginary part of magnetic properties are approximate to 1 and 0. The highest conductivity of 15 % MWCNTs loading is reach to 11.02 (S/m) at 18 GHz. Keywords: composites, dielectric properties, magnetic properties, conductivity

Dielectric properties of vertically aligned multi-walled carbon nanotubes in the terahertz and mid-infrared range

2017 ◽  
Vol 51 (3) ◽  
pp. 034004 ◽  
Author(s):  
Mark D Thomson ◽  
Wissem Zouaghi ◽  
Fanqi Meng ◽  
Matthias M Wiecha ◽  
Kaneez Rabia ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Properties ◽  
Infrared Range ◽  
Mid Infrared ◽  
Multi Walled Carbon Nanotubes ◽  
Vertically Aligned ◽  
Walled Carbon Nanotubes

The I-V Characteristics and Percolation Threshold of the Cement-Based Materials Filled with Multi-Walled Carbon Nanotubes

2009 ◽  
Vol 60-61 ◽  
pp. 36-39
Author(s):  
Jian Lin Luo ◽  
Zhong Dong Duan
Keyword(s):  
Carbon Nanotubes ◽  
Percolation Threshold ◽  
Near Field ◽  
Cement Matrix ◽  
Ultrasonic Dispersion ◽  
Integrated Network ◽  
Cement Based Materials ◽  
Multi Walled Carbon Nanotubes ◽  
Electrode Method ◽  
Walled Carbon Nanotubes

Some multi-walled carbon nanotubes (NMWTs) were firstly dispersed in aqueous solution with surfactant ultrasonic dispersion process, then mixed into cement matrix, casting six groups cement-based materials filled with varying NMWTs additions (nwt) (NFCMs), and as comparison, the plain referential cement paste was fabricated. The ampere-volt (I-V) characteristics and percolation threshold of this type of nanocomposites were focused by four-electrode method. Results show that, the I-V features of the reference has obvious nonlinearity due to polarized reaction within cement hydrated electrolytes after being induced by passing 0~±30 V voltages, those of the NFCMs with six different nwt still have somewhat nonlinear traits, which mainly attribute to the double-layer coatings between NMWTs and out-encapsulated cement hydration isolation. The resistivity (ρ) of the NFCM nanocomposite steadily decreases with the increment of nwt, which contributes to superior capabilities of charge transporter and near-field emission of NMWTs, and the overlapped chance of physical contacts between conducting aggregates of NMWTs and bulk matrix increases by nwt enhancing; although there is still some fluctuation on ρ, but it becomes weaker and weaker by nwt increasing. The percolation threshold of the NFCMs is nwt being 2.0%, and the integrated network pathways at micro-scale form between NMWTs each other through the correspondent NFCM, also revealed in microstructure.

Investigation of Surfactant Type, Dosage and Ultrasonication Temperature Control on Dispersity of Metal-Coated Multi-Walled Carbon Nanotubes

2016 ◽  
Vol 16 (4) ◽  
pp. 4224-4232
Author(s):  
Xiaoning Liang ◽  
Wei Li
Keyword(s):  
Carbon Nanotubes ◽  
Oleic Acid ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Negative Effects ◽  
Ultrasonic Dispersion ◽  
Dispersion Process ◽  
Ultrasonic Assisted ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

We studied the dispersity of multi-walled carbon nanotubes (MWNTs) combined with different metallic particles (Ni and Fe). An ultrasonic-assisted water-bath dispersion process was used to disperse the metal-coated MWNTs in different solutions and the dispersity was measured using an ultraviolet-visible spectrophotometer. The dispersity and morphology of the MWNTs were characterized using field-emission scanning electron microscopy (FE-SEM) together with digital image processing technology. Effects of dispersant type (sodium dodecyl benzene sulfonate (SDBS), oleic acid, and polymer (TNEDIS)) and surfactant dosage on the dispersity of the metal-coated MWNTs were investigated under controlled and uncontrolled temperatures and results were compared with those from the untreated MWNTs. The results showed that the negative effects of temperature on the ultrasonic dispersion process could be eliminated through a temperature-controlled system. Moreover, the TNEDIS, SDBS, and oleic acid were arranged in the descending order of the dispersion effect degree. The untreated MWNTs, Ni-coated MWNTs, and Fe-coated MWNTs were arranged in the descending degree of dispersity order. Since the metal coating makes the MWNTs harder and more fragile, the metal-coated MWNTs are more likely to fracture during the ultrasonic dispersion process.

Selective localisation of multi walled carbon nanotubes in polypropylene/natural rubber blends to reduce the percolation threshold

2015 ◽  
Vol 116 ◽  
pp. 9-17 ◽  
Author(s):  
Sharika Thankappan Nair ◽  
P. Poornima Vijayan ◽  
Priti Xavier ◽  
Suryasarathi Bose ◽  
Soney C. George ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Natural Rubber ◽  
Percolation Threshold ◽  
Rubber Blends ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

scholarly journals Highly Sensitive Humidity Sensors Based on Polyethylene Oxide/CuO/Multi Walled Carbon Nanotubes Composite Nanofibers

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1037
Author(s):  
Waqas Ahmad ◽  
Bushra Jabbar ◽  
Imtiaz Ahmad ◽  
Badrul Mohamed Jan ◽  
Minas M. Stylianakis ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Polyethylene Oxide ◽  
Composite Nanofibers ◽  
Low Cost ◽  
High Sensitivity ◽  
Humidity Sensing ◽  
Sensing Applications ◽  
Multi Walled Carbon Nanotubes ◽  
Lcr Meter ◽  
Walled Carbon Nanotubes

Polymer composites are favorite materials for sensing applications due to their low cost and easy fabrication. In the current study, composite nanofibers consisting of polyethylene oxide (PEO), oxidized multi-walled carbon nanotubes (MWCNT) and copper oxide (CuO) nanoparticles with 1% and 3% of fillers (i.e., PEO–CuO–MWCNT: 1%, and PEO–CuO–MWCNT: 3%) were successfully developed through electrospinning for humidity sensing applications. The composite nanofibers were characterized by FTIR, XRD, SEM and EDX analysis. Firstly, they were loaded on an interdigitated electrode (IDE), and then the humidity sensing efficiency was investigated through a digital LCR meter (E4980) at different frequencies (100 Hz–1 MHz), as well as the percentage of relative humidity (RH). The results indicated that the composite nanofibers containing 1% and 3% MWCNT, combined with CuO in PEO polymer matrix, showed potent resistive and capacitive response along with high sensitivity to humidity at room temperature in an RH range of 30–90%. More specifically, the PEO–CuO–MWCNT: 1% nanocomposite displayed a resistive rapid response time within 3 s and a long recovery time of 22 s, while the PEO–CuO–MWCNT: 3% one exhibited 20 s and 11 s between the same RH range, respectively.

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