Analysis of luminescence, morphological and thermal behaviour of conjugated polymer/CdS electrospun nanofiber

2021 ◽  
pp. 002199832110075
Author(s):  
PS Umabharathi ◽  
S Karpagam
Keyword(s):  
Thermal Stability ◽  
Composite Nanofibers ◽  
Cadmium Sulphide ◽  
Blue Shift ◽  
Sem Analysis ◽  
Tem Analysis ◽  
Good Thermal Stability ◽  
Ftir Technique ◽  
Significant Blue Shift ◽  
Thermal Stability Of

Electro spun composite nanofibers of three series were prepared using different polymers (P1, P2, P3) and cadmium sulphide (CdS). Organic polymers of carbazole based quinoline (P1), quinoxaline (P2), and pyrazine (P3) hybrid with inorganic CdS nanofibers were characterized by XRD and FTIR technique. Collective arrangement of spiderweb-like morphology was observed for all nanofibers. Deviations of absorption and photoluminescence were monitored and a significant blue shift was found after doping CdS and PVA. It was found that the changes in the PL spectra of polymers originated from the chemical interactions between polymer and CdS. The diameter of nanofibers was observed as 127-347 nm from SEM analysis and 66-213 nm from TEM analysis. Optimum thermal stability of the composite nanofibers was achieved up to 200 °C. Compared with pure polymers and CdS, present nanofibers were good thermal stability, apparent blue shift with bluish emission which is suitable for optoelectronics application.

Confinement Barrier Induced Enhancement in Thermal Stability of the Optical Response of InAs/InGaAs/GaAs Submonolayer Quantum Dot Heterostuctures

MRS Advances ◽  
2017 ◽  
Vol 2 (43) ◽  
pp. 2349-2354 ◽  
Author(s):  
Debabrata Das ◽  
Hemant Ghadi ◽  
Sandeep Madhusudan Singh ◽  
Subhananda Chakrabarti
Keyword(s):  
Thermal Stability ◽  
Quantum Dot ◽  
Transition Energy ◽  
Blue Shift ◽  
Ex Situ ◽  
Barrier Layers ◽  
Algaas Layer ◽  
Optical Behavior ◽  
Significant Blue Shift ◽  
Thermal Stability Of

Abstract:In this study the improvement in thermal stability of optical properties of InAs submonolayer quantum dot (SML QD) heterostructures is observed through incorporation of symmetric AlGaAs barrier layers. Low temperature photoluminescence (PL) spectra shows blue shift with less full width at half maxima, ascribe to the assimilation of AlGaAs barrier layers. The sample with confinement enhancing barrier shows the highest ground to ground transition energy with the lowest dot size distribution. Ex situ annealing of as grown samples, followed by PL analysis, confirms the improvement in thermal stability of optical behavior. For the samples with symmetric AlGaAs layer, annealing at higher temperatures under an inert condition can not change the downward transition energy effectively, whereas normal DWELL structures exhibits significant blue shift for the same.

High partial thermal conductivity of luminescence sites: a crucial factor for reducing the heat-induced lowering of the luminescence efficiency

2021 ◽  
Author(s):  
Ni Luo ◽  
Jing Xu ◽  
Xiyue Cheng ◽  
ZhenHua Li ◽  
Yidong Huang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Practical Applications ◽  
Good Thermal Stability ◽  
The Past ◽  
Luminescence Efficiency ◽  
Thermal Stability Of

The good thermal stability of a phosphor is crucial for its practical applications. Unfortunately, in the past decades, only Gurney-Mott equation was available to describe the relation between the luminescence...

Thermal Stability of Solid Aluminum Electrolytic Capacitors with Conductive Polyaniline Counter Electrode

2012 ◽  
Vol 512-515 ◽  
pp. 1018-1021
Author(s):  
Xu Fei Zhu ◽  
Long Fei Jiang ◽  
Wei Xing Qi ◽  
Chao Lu ◽  
Ye Song
Keyword(s):  
Thermal Stability ◽  
Counter Electrode ◽  
Electrolytic Capacitor ◽  
Aluminum Electrolytic Capacitor ◽  
Dodecylbenzenesulfonic Acid ◽  
Excellent Thermal Stability ◽  
High Frequencies ◽  
Solid Aluminum ◽  
Good Thermal Stability ◽  
Thermal Stability Of

To overcome the risk of electrolyte leakage and the shortcoming of higher impedance at high frequencies for the conventional aluminum electrolytic capacitor impregnated with electrolyte solutions, solid aluminum electrolytic capacitor employing conducting polyaniline (PANI) as a counter electrode was developed. The as-fabricated solid capacitors have very low impedances at high frequencies and excellent thermal stability. The superior performances can be ascribed to high conductivity and good thermal stability of the camphorsulfonic acid (CSA)-dodecylbenzenesulfonic acid (DBSA) co-doped PANI.

Synthesis and Application of a Novel Intumescent Flame Retardant Containing Ferrocenyl

2014 ◽  
Vol 1033-1034 ◽  
pp. 931-936
Author(s):  
Cong Yan Chen ◽  
Rui Lan Fan ◽  
Guan Qun Yun
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
Flame Retardants ◽  
Intumescent Flame Retardant ◽  
Limiting Oxygen Index ◽  
Good Thermal Stability ◽  
H Nmr ◽  
Positive Effect ◽  
Thermal Stability Of ◽  
Phosphate Groups

A novel intumescent flame retardant (IFR) containing ferrocene and caged bicyclic phosphate groups, 1-oxo-4-[4'-(ferrocene carboxylic acid phenyl ester)] amide-2, 6, 7-trioxa-1-phosphabicyclo- [2.2.2] octane (PFAM), was successfully synthesized. The synthesized PFAM were added to flammable polyurethane (PU) as flame retardants and smoke suppressants. The structure of PFAM was characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR) and elemental analysis. Thermal stability of PFAM was tested by themogravimetric analysis (TGA). The results revealed that PFAM had good thermal stability and high char weight, the char weight up to 54% at 600 °C. Flammability properties of PU/PFAM composites were investigated by limiting oxygen index (LOI) test and UL-94 test, respectively. The results of LOI tests showed that the addition of PFAM enhanced flame retardancy of PU. When the content of PFAM reaches to 3%, the LOI value is 22.2. The morphologies of the char for PU and PU/3% PFAM composite can be obtained after LOI testing were examined by SEM. The results demonstrated that PFAM could promote to form the compact and dense intumescent char layer. Experiments showed that, the PFAM application of polyurethane showed positive effect.

scholarly journals Electrospun Silk-Boron Nitride Nanofibers with Tunable Structure and Properties

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1093
Author(s):  
Ye Xue ◽  
Xiao Hu
Keyword(s):  
Thermal Stability ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Environmental Research ◽  
Strong Interactions ◽  
Helical Structures ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Thermal Stability Of

In this study, hexagonal boron nitride (h-BN) nanosheets and Bombyx mori silk fibroin (SF) proteins were combined and electrospun into BNSF nanofibers with different ratios. It was found that the surface morphology and crosslinking density of the nanofibers can be tuned through the mixing ratios. Fourier transform infrared spectroscopy study showed that pure SF electrospun fibers were dominated by random coils and they gradually became α-helical structures with increasing h-BN nanosheet content, which indicates that the structure of the nanofiber material is tunable. Thermal stability of electrospun BNSF nanofibers were largely improved by the good thermal stability of BN, and the strong interactions between BN and SF molecules were revealed by temperature modulated differential scanning calorimetry (TMDSC). With the addition of BN, the boundary water content also decreased, which may be due to the high hydrophobicity of BN. These results indicate that silk-based BN composite nanofibers can be potentially used in biomedical fields or green environmental research.

Synthesis, Morphology and Photophysical Properties of Rod-Coil Copolymers

2009 ◽  
Vol 79-82 ◽  
pp. 2095-2098
Author(s):  
Yang Yen Yu ◽  
Wen Chen Chien ◽  
Chung Yi Hsu
Keyword(s):  
Photophysical Properties ◽  
Mixed Solvents ◽  
Blue Shift ◽  
Morphological Transformation ◽  
Good Thermal Stability ◽  
Lamellar Morphology ◽  
Long Rod ◽  
Spherical Micelles ◽  
Large Compound ◽  
Thermal Stability Of

The synthesis, morphology, and photophysical properties of poly[2,7-(9,9- dihexylfluorene)]-block-poly(2-vinyl pyridine) (PF-b-P2VP) with different coil lengths in mixed solvents of THF/methanol are reported. A flakes-like lamellar morphology is observed at a short coil length of PF-b-P2VP. As the coil length increases, a spherical and large compound micelle is formed. Upon further increase of the coil length, the morphological transformation from spherical micelles to long rod-like structures is observed. TGA results indicate a good thermal stability of the prepared copolymers. The spectra of optical absorption for the PF-b-P2VP in solution have a blue shift when the fraction of methanol in the mixed solvent increases. The present study shows that the significance of the rod/coil ratio and selective solvent content on the aggregate morphologies and photophysical properties of the rod-coil block copolymers.

Sputtered Cu Films Containing Various Insoluble Substances for Advanced Barrierless Metallization

2007 ◽  
Vol 539-543 ◽  
pp. 3497-3502 ◽  
Author(s):  
J.P. Chu ◽  
C.H. Lin
Keyword(s):  
Thermal Stability ◽  
Leakage Current ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
The Other ◽  
Oxide Semiconductor ◽  
Good Thermal Stability ◽  
Cu Films ◽  
Pure Cu ◽  
Thermal Stability Of

Sputtered Cu films containing various insoluble substances, such as Cu(W2.3), Cu(Mo2.0), Cu(Nb0.4), Cu(C2.1) and Cu(W0.4C0.7), are examined in this study. These films are prepared by magnetron sputtering, followed by thermal annealing. The crystal structure, microstructure, SIMS depth-profiles, leakage current, and resistivity of the films are investigated. Good thermal stability of these Cu films is confirmed with focused ion beam, X-ray diffractometry, SIMS, and electrical property measurements. After annealing at 400°C, obvious drops in resistivity, to ~3.8 μ-cm, are seen for Cu(W) film, which is lower than the other films. An evaluation of the leakage current characteristic from the SiO2/Si metal-oxide-semiconductor (MOS) structure also demonstrates that Cu with dilute tungsten is more stable than the other films studied. These results further indicate that the Cu(W) film has more thermal stability than the Cu(Mo), Cu(Nb), Cu(C), Cu(WC) and pure Cu films. Therefore, the film is suitable for the future barrierless metallization.

The Experimental Research on the Thermal Properties of Shape-Stabilized Phase Change Materials

2013 ◽  
Vol 291-294 ◽  
pp. 1159-1163
Author(s):  
Quan Ying Yan ◽  
Li Hang Yue ◽  
Li Li Jin ◽  
Ran Huo ◽  
Lin Zhang
Keyword(s):  
Thermal Stability ◽  
Fatty Acid ◽  
Phase Change ◽  
Phase Change Materials ◽  
Liquid Paraffin ◽  
Capric Acid ◽  
Good Thermal Stability ◽  
Change Material ◽  
Thermal Stability Of ◽  
Better Than

This paper investigated the thermal performance of shape stabilized phase change paraffin and shape-stabilized phase change fatty acid. And the PCMs are mixtures of 60% 46# paraffin and 40% liquid paraffin, 65 % 48# paraffin and 35% liquid paraffin,30%capric acid and 70% lauric acid, 30%capric acid and 70% myristic acid. Support material is high-density polyethylene. The results in this paper show that: Thermal stability of both of the two types of phase change materials are good, thermal stability of shape stabilized phase change fatty acid is better than that of paraffin. Results in this paper can provide references and basis for the application of phase change material walls in the practice building.

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