Correlation of glass transition temperature and density with electrical conductivity of lithium sulfoborosilicate glasses

2006 ◽  
Vol 177 (26-32) ◽  
pp. 2747-2751 ◽  
Author(s):  
A DESHPANDE ◽  
V DESHPANDE
Keyword(s):  
Electrical Conductivity ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature

Effects of Electron Beam on Irradiated Polyimide/Polyaniline Composites

2012 ◽  
Vol 550-553 ◽  
pp. 861-864 ◽  
Author(s):  
Sunan Tiptipakorn ◽  
Piriyathorn Suwanmala ◽  
Kasinee Hemvichian ◽  
Yingpit Pornputtanakul
Keyword(s):  
Electrical Conductivity ◽  
Electron Beam ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Radiation Dose ◽  
Radiation Doses ◽  
Pani Composite ◽  
Polyaniline Composites

In this study, the composites prepared from polyimide (PI) and polyaniline (PANI) were radiated with electron beam (EB) at the radiation doses of 0, 50, 150, 200, and 300 kGy. The electrical conductivity and thermal properties of the radiated composites were determined and compared with those of the composites doped with 6M HCl. The results revealed that the electrical conductivity was enhanced from 3.42 x 10-16 S/cm (untreated polyimide without polyaniline) to 6.97 x 10-5 S/cm when the PI/PANI composite was doped with HCl at 10 phr of PANI; furthermore, the conductivity was increased to 2.16 x 10-4 S/cm for the composite at 10 phr of PANI with radiation dose of 200 kGy. In addition, it was found that the glass transition temperature of the composite was increased with the increase of PANI content for either EB radiation method or protonic acid doping method. It could be noted that the electrical conductivity values of the radiated composites were higher than those of composites doped with HCl at the same PANI content.

Characterization of Thermo-Electric Interface Material with Carbon Nanotubes

2007 ◽  
Vol 1056 ◽  
Author(s):  
Piyush R Thakre ◽  
Yordanos Bisrat ◽  
Dimitris C Lagoudas
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Matrix ◽  
Loss Modulus ◽  
Single Wall Carbon Nanotubes ◽  
Electrical Percolation

ABSTRACTAn approach has been presented in the current work to fabricate and characterize nanocomposite systems for optimizing electrical and thermal properties without sacrificing mechanical properties. An epoxy matrix based nanocomposite system has been processed with different volume fractions of carbon nanotubes. The purpose was to tailor macroscale properties to meet competing performance requirements in microelectronics industy. The nanofiller consisted of comparatively low cost XD grade carbon nanotubes (XD-CNTs) that are optimized for electrical properties. This system was compared with another system consisting of single wall carbon nanotubes (SW-CNTs) as nano-reinforcements in epoxy matrix. The electrical percolation threshold (about seven orders of magnitude increase in electrical conductivity) measured by dielectric spectroscopy was found to be at lower loading weight fraction of SWCNTs (0.015 weight %) as compared to XD-CNTs (0.0225 weight %). However, the electrical conductivity after percolation was higher for XD-CNTs reinforced epoxy with respect to SW-CNTs filled nanocomposites. The governing mechanisms for this phenomenon were investigated using transmission optical microscope. The enhancement in thermal conductivity, measured using differential scanning calorimetry, was found to be moderate at lower weight loadings corresponding to electrical percolation. However, a 90% improvement in thermal conductivity was observed for 0.3 weight percent of XD-CNTs. Dynamic mechanical analysis was performed to measure the storage and loss modulus along with the glass transition temperature. No significant change in modulus values and glass transition temperature was measured for nanocomposites varied filler contents with respect to neat matrix.

scholarly journals Structure, thermophysical properties and electrical conductivity of nanocomposites based on epoxy polymer and carbon tubes

2021 ◽  
pp. 7-13
Author(s):  
V.V. Korskanov ◽  
O.M. Fesenko ◽  
V.B. Dolgoshey
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Percolation Threshold ◽  
Thermophysical Properties ◽  
Epoxy Polymer ◽  
Transition Range ◽  
Epoxy Polymers

The aim of this work was to find the optimal conditions for the formation of nanocomposites, study their structure and properties and conditions for the formation of multicomponent materials based on epoxy polymers and carbon nanotubes with predetermined performance properties. The basis for the formation of epoxy polymers was an epoxydian oligomer (EDO) based on bisphenol A. Polypox H354 was used as a hardener for EDO. Carbon nanotubes (CNT) were used as a nanofiller for the preparation of nanocomposites. The research methods were a diffractometer for measuring the intensity of X-ray scattering in the region of small angles and a differential scanning calorimeter for obtaining heating thermograms. The electrical conductivity of the samples at a temperature of 293 K was measured at direct current according to the two-electrode scheme. In this work the structure, thermophysical properties and electrical conductivity of nanocomposites based epoxy polymers and carbon  nanotubes have been studied. It was found that at low CNT content the formation of nanocomposites occurs by the mechanism of epoxy network growth, which is accompanied by the displacement of CNT particles to the periphery of the epoxy matrix. This process is accompanied by an increase in the scattering intensity of the SAXS, a rapid increase in the glass transition temperature and the degree of crosslinking of the epoxy polymer. When the critical concentration is reached, CNT particles form a continuous cluster, which leads to occurrence percolation threshold, reducing the glass transition temperature, expanding the glass transition range, occurrence of pores and reducing the degree of completion of the crosslinking reaction in nanocomposites relative to the epoxy polymer. It is established that the improvement of nanocomposite properties and the occurrence of the percolation threshold is due to the maximum specific energy of ER-CNT interaction and is achieved at a critical mass concentration of nanofiller from 0,1% to 0,4%.

scholarly journals Spectroscopic and Physical Properties of --ZnO- Glasses

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Shashidhar Bale ◽  
Syed Rahman
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Heat Capacity ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Electrical Conduction ◽  
Glass Network ◽  
Dc Electrical Conductivity ◽  
Conduction Properties

Bismuth glasses containing ZnO and Li2O were prepared by conventional melt-quench technique. ZnO is gradually substituted by Li2O, and its effect on various physical, thermal, and electrical conduction properties was studied and analyzed. Raman studies revealed that these glasses are mainly made up of [BiO3] and [BiO6] units. The density decreases and molar volume increases with the incorporation of Li2O into these glasses. MDSC studies have been performed on these glasses to determine the glass transition temperature and other related thermal parameters such as change in the glass transition temperature () and specific heat capacity difference (). These studies revealed that the glasses possess high values, and decreases with Li2O content. The trend of these properties is attributed to the changes in the glass network structure. Dc electrical conductivity revealed that the conductivity increases and activation energy decreases with Li2O content.

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