Tailoring the Optical Properties of Polymers Blend Nanocomposites

The presented work deals with the structural and optical properties of chemically synthesized TiO2 nanoparticles filled PC/PS blend nanocomposites. A series of PC/PS (100/0, 50/50, 0/100 wt%/wt %) -TiO2 (1, 2, 3 wt %) blend nanocomposites have been prepared by solution casting method. Prepared blend nanocomposites have been subjected to XRD, SEM and FTIR for structural analysis. Optical constants have been analyzed using UV-Vis spectroscopy. The XRD, SEM and FTIR spectrum confirms the formation of PC/PS-TiO2 blend nanocomposites. Results reveal the decrease in band gap and enhancement in optical constants like, extinction coefficient, refractive index and dielectric constants of blend nanocomposites with nanofiller TiO2 content

Synthesis and Crystallization Studies of Thermo-plastic Polyster/Titania Nanocomposites

The present work reports the non-isothermal crystallization kinetics of PET-TiO2 nanocomposites. The average particle size of TiO2 nanoparticles, prepared by chemical route, has been calculated 32 nm using Debay-Scherrer’s formula in XRD peaks. PET-TiO2 nanocomposites have been synthesized using solution casting method. The investigation of non-isothermal crystallization behavior has been conducted by means of Differential Scanning Calorimeter (DSC). The crystallization temperature shift to lower temperature for both PET pristine and PET-TiO2 nanocomposites due to decrease in mobility of chain segments and heterogeneous nucleation. Also, the inclusion of TiO2 nanoparticles may accelerate nucleation rate in nanocomposites that causes the crystallization time and absolute crystallinity fraction. The thermal conductivity of inorganic filler TiO2 nanoparticles may affect the crystallization temperature

Research and Reviews: Journal of Material Sciences Bond Formation Perspective: Effect of Sn Addition in Se-Te-Sn Chalcogenide Glasses

ABSTRACT The aim of this study is to investigate the effect of Tin (Sn) addition on Band gap (Eg) and Dc conductivity of Se-Te-Sn semi-conducting glasses. This is an effort towards the understanding of physics of temperature dependence of dc electrical volume conductivity of Se75Te25-xSnx (X= 2, 4, 6 & 8) glasses in bulk form. These Chalcogenide glasses were prepared by melt quenching (rapid cooling of melt) technique. The amorphous nature of as prepared glass was confirmed by XRD. Using Keithley Electrometer / High resistance Meter 6517 A, the I-V characteristics of these glasses have been recorded in a temperature range from room temperature to 100˚C. Additionally, the Poole-Frenkel conduction mechanism has also been verified in order to investigate the good agreement with the established fact that most of Chalcogenide glasses obey Poole-Frenkel conduction mechanism. To calculate the Band gap, with the help of Ocean Optics Spectrophotometer, absorption spectra has been recorded. Analysis of these absorption spectra using Tauc relation reveals that these glasses are semiconducting and direct band gap material

Electrical measurements of Se_85-xTe₁₅Sb_xglasses

782-785Temperature dependence of I-V characteristics and dc conductivity of Se85-xTe15Sbx (where x= 2, 4, 6, 8 and 10) glasses in the form of thin pellets has been studied. The pellets have been prepared from the ingots of glasses in the powder form. It is quite evident from I-V characteristics that the glass containing 4 at wt % of Sb allow maximum current to pass through itself as compared to its other counterparts of the series. The linear relationship between ln (I) and V1/2 strongly suggests the type of conduction as the Poole-Frenkel. The deviation from ohmic behaviour at lower voltages towards the non-ohmic behaviour at higher voltages is due to the additional thermal effects at higher temperatures induced in the sample. The electrical conductivity of these samples for the above-mentioned compositions using their I-V characteristics has been determined. The variations of electrical conductivity with composition at all temperatures show that Se81Te15Sb4 glass has the maximum conductivity. This variation is explained using the bonding between Se and Sb at different compositions. Hence, the composition Se81Te15Sb4 is more chemically ordered and electrically conducting as compared to other members of the series

<i style="">I-V</i> measurements of chalcogenide glass thin films

196-200Measurements of I-V characteristics of Se85-xTe15Sbx (where x = 2, 4, 6, 8 and 10) glassy thin films have been carried out at ambient conditions. These measurements have been taken using Keithley Electrometer/High Resistance Meter 6517A in its force voltage measure current (FVMI) mode. Measurements show that the film containing 4 at. wt. % of Sb allows the maximum current to pass through itself as compared to other counterparts of this series. The composition dependence of resistance has been explained on the basis of bond formation between Se and Sb at different compositions and hence Se81Te15Sb4 composition could be termed as “critical composition” in the series under test as it is also strongly supported by dc electrical conductivity, thermal conductivity and thermal diffusivity measurements of these materials in bulk. Besides, the linear relationship between ln (I) and V1/2 confirm the conduction mechanism as to be Poole-Frenkel type