Characterization of Electrical Conductivity of Carbon Nanotube Composites

2014 ◽  
Author(s):  
Shen Gong ◽  
Zhenghong Zhu ◽  
Jun Li
Keyword(s):  
Electrical Conductivity ◽  
Surface Modification ◽  
Polymer Composites ◽  
Structural Integrity ◽  
Epoxy Composites ◽  
Sem Images ◽  
Low Viscosity ◽  
Before And After ◽  
Nanotube Composites

This work investigated and characterized the electrical conductivity of carbon nanotubes (CNT)/polymer composites. Surface modification has been applied to improve the homogeneous dispersion of MWCNTs in epoxy. After treatment, MWCNTs were mixed into low viscosity epoxy matrix at room temperature. Dispersion and structural integrity of MWCNTs before and after surface modification were examined by SEM images. The dispensability of treated MWCNTs and electrical conductivity of nanocomposites are evaluated and also compared with MWCNTs/polymer composites in literature prepared using the same commercial MWCNTs. The electrical conductivity of MWCNTs and MWCNTs/epoxy composites were evaluated by the four-point probe method. The results of electrical property will lay a foundation for establishing the relationship between electrical resistance and strain of MWCNTs/epoxy composites. The results also confirm that reducing CNT agglomerate size can greatly improve the electrical conductivity of composite and decrease the percolation threshold.

scholarly journals Characterization of continuous Hibiscus sabdariffa fibre reinforced epoxy composites

2022 ◽  
Vol 30 ◽  
pp. 096739112110609
Author(s):  
Atik Mubarak Kazi ◽  
Ramasastry DVA
Keyword(s):  
Fibre Orientation ◽  
Stress Transfer ◽  
Dynamic Mechanical Properties ◽  
Epoxy Composites ◽  
Neat Epoxy ◽  
Hibiscus Sabdariffa ◽  
Sem Images ◽  
Fibre Composites ◽  
The Matrix

The influence of fibre orientation on physical, mechanical and dynamic mechanical properties of Hibiscus sabdariffa fibre composites has been studied. The composites with longitudinal (0°), transverse (90°) and inclined (45°) fibre orientation were prepared using the hand layup technique. ASTM standards were used for characterization of continuous Hibiscus sabdariffa fibre composites. The composite with longitudinally placed fibres yields improved mechanical characteristics. The addition of longitudinal (0°) oriented continuous Hibiscus sabdariffa fibres to the epoxy enhances tensile strength by 460%, flexural strength by 160% and impact strength by 603% compared to neat epoxy. The longitudinal (0°) fibre oriented composite offers higher resistance to water absorption and thickness swelling compared to other types of composites. All continuous Hibiscus sabdariffa fibre epoxy composites possess an improved storage modulus than the neat epoxy resin. The glass transition temperature of continuous Hibiscus sabdariffa fibre composites is 8%–31% lower than that of neat epoxy. Scanning electron microscopy (SEM) images confirm the existence of voids in the matrix, fibre pullout and crack propagation near the fibre bundle, which indicates the stress transfer between fibre and matrix is non-uniform.

scholarly journals Synthesis and Characterization of Hollow-Sphered Poly(N-methyaniline) for Enhanced Electrical Conductivity Based on the Anionic Surfactant Templates and Doping

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1023
Author(s):  
Chatrawee Direksilp ◽  
Anuvat Sirivat
Keyword(s):  
Thermal Stability ◽  
Electrical Conductivity ◽  
Doping Level ◽  
Anionic Surfactants ◽  
Sodium Dodecylsulfate ◽  
Sem Images ◽  
Dioctyl Sodium Sulfosuccinate ◽  
Surfactant Templates ◽  
Particle Shapes

Poly(N-methylaniline) (PNMA) is a polyaniline derivative with a methyl substituent on the nitrogen atom. PNMA is of interest owing to its higher solubility in organic solvents when compared to the unsubstituted polyaniline. However, the electrical conductivity of polyaniline derivatives suffers from chemical substitution. PNMA was synthesized via emulsion polymerization using three different anionic surfactants, namely sodium dodecylsulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), and dioctyl sodium sulfosuccinate (AOT). The effects of surfactant structures and concentrations on electrical conductivity, doping level, crystallinity, morphology, and thermal stability were investigated. The re-doping step using perchloric acid (HClO4) as a dopant was sequentially proceeded to enhance electrical conductivity. PNMA synthesized in SDBS at five times its critical micelle concentration (CMC) demonstrated the highest electrical conductivity, doping level, and thermal stability among all surfactants at identical concentrations. Scanning electron microscopy (SEM) images revealed that the PNMA particle shapes and sizes critically depended on the surfactant types and concentrations, and the doping mole ratios in the re-doping step. The highest electrical conductivity of 109.84 ± 20.44 S cm−1 and a doping level of 52.45% were attained at the doping mole ratio of 50:1.

Piezoresistance Characterization of Poly(Dimethyl-Siloxane)-Multiwall Carbon Nanotube Composites

2010 ◽  
Author(s):  
Reza Rizvi ◽  
Sara Makaremi ◽  
Steven Botelho ◽  
Elaine Biddiss ◽  
Hani Naguib
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Multiwall Carbon Nanotube ◽  
Dimethyl Siloxane ◽  
Conducting Filler ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Electronic Textile ◽  
Multiwall Carbon

This study examines the piezoresistive behavior of polymer-conducting filler composites. Piezoresistive composites of Poly(dimethyl-siloxane)-Multiwall Carbon Nanotube (PDMS-MWNT) were prepared using a direct mixing approach. The dispersion and the electrical conductivity of the composites were characterized at various MWNT compositions. The piezoresistive behavior under compression was measured using an Instron Universal Tester/Digital Sourcemeter combination. Negative piezoresistive behavior was observed signifying a reducing mean inter-particulate distance in the composites. Moreover, the sensitivities increased at two compositional values of 3 and 5 wt% MWNT in PDMS, which was associated with the state of MWNT dispersion observed. Tensile piezoresistive behavior of the PDMS-MWNT adhered on a fabric substrate was also characterized. Positive piezoresistive values, indicating increasing inter-particulate distance, were observed. Significant challenges in the implementation of PDMS-MWNT as sensory materials in electronic-textile applications were observed as a result of this study and have been discussed.

The Surface Chemistry Characterization of Pyrite, Sphalerite and Molybdenite after Bioleaching

2017 ◽  
Vol 262 ◽  
pp. 487-491 ◽  
Author(s):  
Sina Ghassa ◽  
Hadi Abdollahi ◽  
Mahdi Gharabaghi ◽  
Saeed Chehreh Chelgani ◽  
Mohammad Jafari
Keyword(s):  
Surface Chemistry ◽  
Dissolution Kinetics ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Chemical Leaching ◽  
Characterization Methods ◽  
X Ray ◽  
Ash Layer ◽  
Before And After

The mineral surface chemistry characterization is essential to describe the dissolution kinetics in leaching and bioleaching. Five different methods, including X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy, have been applied to study the surface chemistry changes during pyrite, sphalerite and molybdenite bioleaching. The surface characterizations have been done for samples before and after biological and chemical leaching. The SEM images illustrated that the minerals surfaces were smooth before processing, while they covered with an ash layer after biological treatment. Although EDS analysis and Raman spectrum demonstrated the potassium jarosite formation on the pyrite surface during bioleaching, the formation of jarosite layer did not occur on the sphalerite surfaces during bioleaching. On the other hand, a sulfur layer formation on the sphalerite surface was confirmed by mentioned characterization methods. Finally, according to the XRD and EDS spectrum the molybdenite surface had been covered both with sulfur and jarosite.

scholarly journals Antimicrobial Surface Functionality of PEG Coated and AgNPs Immobilized Extracorporeal Biomaterials

2021 ◽  
Vol 12 (1) ◽  
pp. 1039-1052
Keyword(s):  
Surface Modification ◽  
Biomedical Applications ◽  
Antimicrobial Activities ◽  
Klebsiella Pneumonia ◽  
Colloidal Silver ◽  
Sem Images ◽  
Surface Functionality ◽  
Antimicrobial Function ◽  
Peg Coating

Nanotechnology is a promising field for generating new medicine applications like colloidal silver to prevent nosocomial infections. In this study, the objection of the presented manuscript was to test the antimicrobial activity of PEG/silver nanoparticles (AgNPs) coated blood tubing used in hemodialysis. The modification of plastic tubing was first performed by PEG coating, which was followed by immobilization of AgNPs synthesized with a green chemical approach from the leaves of Liquidambar Orientalis Miller. The stabilization of each surface modification stage was assured by methanol fixation. The characterization of AgNPs, surface modification steps, and final tubing surface appearances was performed by spectrophotometric measurements, DLS analysis, FTIR spectrums, and SEM images. The results indicated that the surfaces of hemodialysis tubing were successfully coated with PEG/AgNPs processed sequentially. Antimicrobial activities were evaluated against pathogens (Escherichia coli, Pseudomonas aeruginosa. Klebsiella pneumonia, Staphylococcus aureus, and Candida albicans), which are commonly involved in catheter-related infections. In conclusion, a new AgNPs immobilization method to polymeric catheter surfaces after PEG layering was developed. The antimicrobial function against five nosocomial microorganisms would have potential in biomedical applications.

scholarly journals Preparation and Characterization of poly-aniline hydrochloride (PANI-HCL) Nano-composites by Radiation

2019 ◽  
Vol 27 (2) ◽  
pp. 27-37
Author(s):  
Moamar H. Idan ◽  
Raheem G. Kadhim
Keyword(s):  
Electrical Conductivity ◽  
Polymer Mixture ◽  
Prepared Film ◽  
Casting Method ◽  
Aniline Hydrochloride ◽  
Color Changes ◽  
Before And After ◽  
Ft Ir ◽  
Poly Aniline

      During this search, the polymer poly-aniline hydrochloride (PANI-HCL)  was prepared with different weights before and after irradiation in the form of films using the casting method. The films were recorded with the cobalt element(CO60), which sends a gama (1.2) Mev for a period of (72) hours. The structural properties of the (FT-IR) were studied. The results showed that the active groups of the recorded polymer were consistent with the chemical composition and topographic study of the prepared film surfaces. The images showed that the recorded polymer is homogeneous and its color changes after irradiation.       The electrical properties included the measurement of the hall effect and the continuous electrical conductivity and the behavior of the current and voltages where the results showed that the Hall coefficient of the polymer mixture recorded before and after the irradiation are carriers of the (n-type) and through the measurement of current- voltages show results that the polymer recorded conduct the behavior of ohmic before irradiation and walk Conduction of a semiconductor after irradiation. In addition, the results of electrical conductivity were shown to be less after irradiation.

scholarly journals Carbon nanotube-reinforced smart composites for sensing freezing temperature and deicing by self-heating

2018 ◽  
Vol 8 ◽  
pp. 184798041877647 ◽  
Author(s):  
Sung-Hwan Jang ◽  
Yong-Lae Park
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Polymer Composites ◽  
Freezing Temperature ◽  
Coating Materials ◽  
Smart Composites ◽  
Self Heating ◽  
Nanotube Composites ◽  
Shear Mixing ◽  
Carbon Nanotube Composites

Carbon nanotube-reinforced polymer composites were fabricated by high shear mixing. The microstructure and the electrical properties of the carbon nanotube–polymer composites were investigated by scanning electron microscopy and electrical resistance measurement. We found that the carbon nanotube composites showed high electrical conductivity (1.5 S m−1) at 7.0 wt% of carbon nanotubes, and the increase in thickness enhanced the electrical conductivity of the composites. The multifunctional properties of the carbon nanotube composites were also investigated for use in sensing the freezing temperature and also in deicing by self-heating. The results showed that the carbon nanotube–polymer composites had high temperature sensitivity in the freezing temperature range from −5 to 5 C and an excellent heating performance due to the Joule heating effect. The carbon nanotube composites are promising to be used as smart coating materials for deicing by self-heating as well as by detection of the freezing temperature.

Wafer Bumping and Characterizations of Fine-Pitch Lead-Free Solder Microbumps on 12” (300mm) wafer for 3D IC Integration

2011 ◽  
Vol 2011 (1) ◽  
pp. 000650-000656
Author(s):  
J. H. Lau ◽  
P-J Tzeng ◽  
C-K Lee ◽  
C-J Zhan ◽  
M-J Dai ◽  
...  
Keyword(s):  
Cross Sections ◽  
Lead Free ◽  
Lead Free Solder ◽  
Sem Images ◽  
3D Ic ◽  
Fine Pitch ◽  
Solder Bumps ◽  
Before And After ◽  
Free Solder

In this study, the wafer bumping and characterization of fine-pitch lead-free solder microbumps on 300mm wafer for 3D IC integration are investigated. Emphasis is placed on the Cu-plating solutions (conformal and bottom-up). Also, the amount of Cu and solder (Sn) volumes is examined. Furthermore, characterizations such as shearing test and aging of the microbumps are provided and cross sections/SEM images of the microbumps before and after test are discussed. Finally, the process windows of applying the conventional electroplating wafer bumping method of the ordinary solder bumps to the microbumps are also presented.

Fabrication and Characterization of Hydroxyapatite Nanocomposites Based on Bacterial Cellulose with Surface Modification

2012 ◽  
Vol 476-478 ◽  
pp. 457-460 ◽  
Author(s):  
Na Yin ◽  
Shi Yan Chen ◽  
Yang Ou Yang ◽  
Lian Tang ◽  
Zhe Li ◽  
...  
Keyword(s):  
Surface Modification ◽  
Bacterial Cellulose ◽  
Three Dimensional ◽  
Biomimetic Synthesis ◽  
Sem Images ◽  
Xrd Pattern ◽  
Fabrication And Characterization ◽  
Sbf Solution ◽  
Great Potential Application

In this study, biomimetic synthesis of hydroxyapatite (HAp) nanocomposites based on bacterial cellulose (BC) with sodium alginate (SA) surface modification was studied. The results showed that SA treatment promoted the apatite nucleation ability of BC in SBF solution. The FE-SEM images demonstrated that HAp nanoparticles were successfully formed in the three dimensional nanofiber network of BC. FTIR spectra indicated that the obtained HAp crystals were partially substituted with carbonate, which were very similar with natural bones. It was also found that both of crystallite size and crystallinity of HAp crystals observed from XRD pattern were very low. The resultant nanocomposites consisted of nano-scale HAp crystals and SA treated BC nanofibrous have great potential application in bone tissue engineering.

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