scholarly journals Robust measurements of electric conductivity in polyethylene based materials: measurement setup, data processing and impact of sample preparation

Author(s):  
Xiangdong Xu ◽  
M Karlsson ◽  
K. Gaska ◽  
Stanislaw Gubanski ◽  
Henrik Hillborg ◽  
...  

<p>In this work, a measurement setup and an algorithm are introduced that allow for obtaining and processing the current data during standard measurements of electric conductivity in polymeric insulation materials. Robustness of this setup is demonstrated through dc conductivity measurements of low density polyethylene (LDPE) specimens that were prepared by two different techniques, i.e. compression molding and extrusion, at two independent laboratories (at Chalmers and KTH) from the same raw pellets. The results resented in this paper reveal that the implemented data processing algorithm allows for clear separation of the conduction current level and the external noise and thus for good differentiation between the conductivity levels in the investigated material specimens. In addition, a high reproducibility of the results is obtained for the independently manufactured specimens, suggesting the proposed measurement technique is well suitable for characterization of low conducting dielectrics.</p>

1992 ◽  
Vol 293 ◽  
Author(s):  
Herve Cheradame ◽  
F. Desbat ◽  
P. Mercier-Niddam ◽  
S. Boileau

AbstractIonically conducting materials containing PEO were prepared from telechelic di(methyl-diethoxy-silane) PEO, synthesized by the hydrosilylation of telechelic diallyl-PEO with methyldiethoxysilane. The network is obtained by the usual sol-gel chemistry. Then, it is filled with LiClO4 by diffusion of the salt and further drying. A comparison is made with the same kind of materials crosslinked using urethane chemistry. Diffusion studies show that the diffusion coefficient of solvent is similar for both types of materials, whilst the ionic conductivity is higher for the networks crosslinked with siloxane bonds. An experiment of diffusion of LiClO4 without solvent showed that this salt has a diffusion coefficient of the order of 2.10-8 cm2.sec-1 at 34°C. The conductivity calculated from this determination is compatible with the mechanism of lithium cation transport by the diffusion of salt molecules. Elasticity modulus measurements show that the salt aggregates are essentially located within the crosslinks at low concentration, but also in the PEO chains for salt concentrations higher than 1 mol/l.


Author(s):  
Gildardo Gutiérrez-Vargas ◽  
Alberto Ruiz ◽  
Víctor H. López ◽  
Jin-Yeon Kim ◽  
Jorge A. González-Sánchez ◽  
...  

2000 ◽  
Author(s):  
Theodorian Borca-Tasciuc ◽  
Weili Liu ◽  
Jianlin Liu ◽  
Kang L. Wang ◽  
Gang Chen

Abstract In this work, we present experimental results on the in-plane and cross-plane thermal conductivity characterization of a Si/Ge quantum-dots superlattice structure. The quantum-dots superlattice was grown by molecular-beam-epitaxy and self-organization. The anisotropic thermal conductivity measurements are performed by a differential two-wire 3ω method. The measured in-plane and cross-plane thermal conductivity values show a different temperature behavior. The results are compared and explained with heat transport models in superlattices.


2002 ◽  
Vol 4 (4) ◽  
pp. 281-295 ◽  
Author(s):  
Jose González-García ◽  
Angel Frías-Ferrer ◽  
Vicente Montiel ◽  
Antonio Aldaz ◽  
Juan A. Conesa

This paper analyses the hydrodynamic behaviour of electrochemical reactors by simulating stimulus–response experiments. The experiments were performed with a simple experimental arrangement to generate data (Residence Time Distribution (RTD) curves) from electrolytic conductivity measurements. The multiparametric model proposed and the Matlab program developed allow the study of electrochemical reactors using three-dimensional electrodes, providing values of characteristic parameters of the materials, such as porosity and compressibility. The study of the reactor also permits modelling of the electrochemical reactions that will be produced inside it.


2010 ◽  
Vol 6 (3) ◽  
pp. 275-279
Author(s):  
Sentot Budi Rahardjo ◽  
Abu Masykur ◽  
Melin Puspitaningrum

Complex of cobalt(II) with sulfisoxazole (slfs) has been synthesized in 1 : 4 mole ratio of metal to ligands in methanol, the complex formula is [Co(slfs)3(H2O)3]SO4.nH2O. The electric conductivity of the complex in methanol correspond to 1:1 electrolyte. The thermal analysis indicates that complex contain some hydrates. Magnetic Susceptibility measurements show that the complex is paramagnetic with µeff = 4,60(9) BM. Infra red spectra indicates that the primary N-H group coordinated to the center ion, it is signed by a shift of primary N-H group absorption. UV-Vis spectrum appears one peak at λ= 515,5 nm (19.342 cm-1) due to transition peak of 4T1g (F) → 4T2g (P) (ν3) overlay to transition peak of 4T1g(F) → 4A2g(F) (ν2). The value of 10 Dq (Δo) that corresponds to transition 4T1g → 4T2g (n1) is 95,29 kJ.mol-1. Cyclic voltammograms have revealed quasi reversible. The complex probably is octahedral.   Keywords: cobalt(II), sulfisoxazole, complex, paramagnetic, octahedral


2013 ◽  
Vol 10 (3) ◽  
pp. 597-606
Author(s):  
Baghdad Science Journal

New (pentulose-?-lactone-2,3-enedibenzoate barbituric acid) (L) have been synthesized by reaction of (5-C-dimethyl malonyl-pentulose-?-lactone-2,3-enedibenzoate) with urea in alkaline media (sodium methoxide). (Ca+2, Co+2, Ni+2, Cu+2, Zn+2, Cd+2 and Hg+2) complexes of (pentulose-?-lactone-2,3-enedibenzoate barbituric acid) (L) have been prepared and characterized by (1H and 13CNMR), FTIR, (U.V-Vis) spectroscopy, Atomic absorption spectrophotometer (A.A.S), Molar conductivity measurements and Magnetic moment measurements, and the following general formula has been given for the prepared complexes [MLCl2(H2O)].XH2O, where M = (Ca+2, Co+2, Ni+2, Cu+2, Zn+2, Cd+2, Hg+2), X = five molecules with (Cd+2) complex, L = (pentulose-?-lactone-2,3-enedibenzoate barbituric acid).


2010 ◽  
Vol 663-665 ◽  
pp. 542-545 ◽  
Author(s):  
Bing Jie Zhu ◽  
Xin Wei Wang ◽  
Mei Fang Zhu ◽  
Qing Hong Zhang ◽  
Yao Gang Li ◽  
...  

The PANI/ITO conducting nanocomposites have been synthesized by in-situ polymerization. The obtained nanocomposites were characterized by X-ray diffraction pattern, scanning electron microscopy and Fourier transform infrared. Electrical conductivity measurements on the samples pressed into pellets showed that the maximum conductivity attained 2.0 ± 0.05 S/cm for PANI/ITO nanocomposites, at ITO doping concentration of 10 wt%. The results of the present work may provide a simple, rapid and efficient approach for preparing PANI/ITO nanocomposites.


2022 ◽  
pp. 146906672110733
Author(s):  
Sean Sebastian Hughes ◽  
Marcus M. K. Hughes ◽  
Rasmus Voersaa Jonsbo ◽  
Carsten Uhd Nielsen ◽  
Frants Roager Lauritsen ◽  
...  

Beer is a complex mix of more than 7700 compounds, around 800 of which are volatile. While GC-MS has been actively employed in the analysis of the volatome of beer, this method is challenged by the complex nature of the sample. Herein, we explored the possible of using membrane-inlet mass spectrometry (MIMS) coupled to KNIME to characterize local Danish beers. KNIME stands for Konstanz Information Miner and is a free open-source data processing software which comes with several prebuilt nodes, that, when organized, result in data processing workflows allowing swift analysis of data with outputs that can be visualized in the desired format. KNIME has been shown to be promising in automation of large datasets and requires very little computing power. In fact, most of the computations can be carried out on a regular PC. Herein, we have utilized a KNIME workflow for data visualization of MIMS data to understand the global volatome of beers. Feature identification was not possible as of now but with a combination of MIMS and a KNIME workflow, we were able to distinguish beers from different micro-breweries located in Denmark, laying the foundation for the use of MIMS in future analysis of the beer volatome.


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