The N,N-dimethylformamide + ethane-1,2-diol solvent system. Dielectric constant, refractive index, and related properties at various temperatures

1991 ◽  
Vol 36 (4) ◽  
pp. 365-368 ◽  
Author(s):  
Andrea Marchetti ◽  
Carlo Preti ◽  
Mara Tagliazucchi ◽  
Lorenzo Tassi ◽  
Giuseppe Tosi
2016 ◽  
Vol 7 ◽  
pp. 1141-1155 ◽  
Author(s):  
Tomasz Tański ◽  
Wiktor Matysiak ◽  
Barbara Hajduk

The aim of this study was to produce nanocomposite polymer fibres, consisting of a matrix of polyacrylonitrile (PAN) and a reinforcing phase in the form of SiO2/TiO2/Bi2O3 nanoparticles, by electrospinning the solution. The effect of the nanoparticles and the electrospinning process parameters on the morphology and physical properties of the obtained composite nanofibres was then examined. The morphology of the fibres and the dispersion of nanoparticles in their volume were examined using scanning electron microscopy (SEM). All of the physical properties, which included the band gap width, dielectric constant and refractive index, were tested and plotted against the concentration by weight of the used reinforcing phase, which was as follows: 0%, 4%, 8% and 12% for each type of nanoparticles. The width of the band gap was determined on the basis of the absorption spectra of radiation (UV–vis) and ellipsometry methods. Spectroscopic ellipsometry has been used in order to determine the dielectric constant, refractive index and the thickness of the obtained fibrous mats.


1936 ◽  
Vol 9 (2) ◽  
pp. 296-300
Author(s):  
Shû Kambara

Abstract Natural rubber was purified by Pummerer's method and was dissolved in benzene and ether. The dielectric constant, refractive index, density, and concentration of the solutions were determined. From these data, the molecular polarization and dipole moment were calculated on the assumption that the rubber was dissolved in a molecular state of (C5H8)8. The dipole moments of total and gel rubber were found to be 2.45 and 2.91 × 10−18, respectively. These values are of the same order of magnitude as those of masticated crude rubber obtained by Ostwald. It may be said that the impurities of rubber are interlocked mechanically on the rubber molecule and are not combined chemically. Sol rubber in ether solution shows a far lower value than the values of total and gel rubber. These latter values may be influenced by autoöxidation, and the true value of the rubber hydrocarbon may be far smaller than the result described in this paper.


In this work, we studied the effect of annealing temperature on the structural and solid state properties of AlZnO thin films using Chemical bath deposition technique. The thin films grown was annealed at various temperatures of 100oC, 150oC to 200oC The morphological and structural properties were studied using XRD and SEM, while the optical properties were studied using UVVIS Spectroscopy from where the bad gap, dielectric constant, refractive index, extinction coefficient and optical conductivity were deduced from the theoretical equations.From the result, it is observed that there is effect of annealing temperature on these properties such that the grain size and x-ray characteristics depicted different characteristics at these various temperatures.


2010 ◽  
Vol 18 (24) ◽  
pp. 24859 ◽  
Author(s):  
Xuefeng Wang ◽  
Kuo-ping Chen ◽  
Ming Zhao ◽  
David D. Nolte

Sign in / Sign up

Export Citation Format

Share Document