scholarly journals Effect of High Temperature on the Electrochemical and Optical Properties of Emeraldine Salt Doped with DBSA and Sulfuric Acid

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Salma Gul ◽  
Anwar-ul-Haq Ali Shah ◽  
Salma Bilal
Keyword(s):  
Thermal Stability ◽  
Cyclic Voltammetry ◽  
Sulfuric Acid ◽  
Effect Of Temperature ◽  
Visible Spectroscopy ◽  
Emeraldine Salt ◽  
Higher Temperature ◽  
Stability Effect ◽  
Thermal Stability Of ◽  
Comprehensive Study

A comprehensive study of thermally treated polyaniline in its emeraldine salt form is presented here. It offers an understanding of the thermal stability of the polymer. Emeraldine salt was prepared by a novel emulsion polymerization pathway using dodecylbenzene sulfonic acid and sulfuric acid together as dopants. The effect of temperature and heating rate on the degradation of this emeraldine salt was studied via thermogravimetric analysis. The thermally analyzed sample was collected at various temperatures, that is, 250, 490, 500, and 1000°C. The gradual changes in the structure of the emeraldine salt were followed through cyclic voltammetry, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy. Results demonstrate that emeraldine salt shows high thermal stability up to 500°C. This is much higher working temperature for the use of emeraldine salt in higher temperature applications. Further heat treatment seems to induce deprotonation in emeraldine salt. Cyclic voltammetry and ultraviolet-visible spectroscopy revealed that complete deprotonation takes place at 1000°C where it loses its electrical conductivity. It is interesting to note that after the elimination of the dopants, the basic backbone of emeraldine salt was not destroyed. The results reveal that the dopants employed have a stability effect on the skeleton of emeraldine salt.

Systematic Characterization of Different Quaternary Ammonium Salts to be Used in Organoclays

2012 ◽  
Vol 727-728 ◽  
pp. 1552-1556
Author(s):  
Renata Barbosa ◽  
Dayanne Diniz Souza ◽  
Edcleide Maria Araújo ◽  
Tomás Jefférson Alves de Mélo
Keyword(s):  
Thermal Stability ◽  
Quaternary Ammonium ◽  
Chemical Structure ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Degradation Mechanisms ◽  
Scanning Calorimetry ◽  
Higher Temperature ◽  
Thermal Stability Of

Studies of degradation have verified that the decomposition of some quaternary ammonium salts can begin to be significant at the temperature of about 180 ° C and like most thermoplastics are processed at least around this temperature, the thermal stability of the salt in clay should always be considered. Some salts are more stable than others, being necessary to study the degradation mechanisms of each case. In this work, four quaternary ammonium salts were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG). The results of DSC and TG showed that the salts based chloride (Cl-) anion begin to degrade at similar temperatures, while the salt based bromide (Br-) anion degrades at higher temperature. Subsequently, a quaternary ammonium salt was chosen to be used in organoclays, depending on its chemical structure and its thermal behavior.

A Comparative Study of Metal Oxides (CaO, CuO and CaO/CuO) Effects on the Morphology and Thermal Stability of PANI Nanofibers

2015 ◽  
Vol 819 ◽  
pp. 262-267
Author(s):  
Mohammad Mizanur Rahman Khan ◽  
Wan Ahmad Kamil Mahmood ◽  
Yee Keat Wee ◽  
Hanis binti Azizan
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Surface Morphology ◽  
Secondary Growth ◽  
Visible Spectroscopy ◽  
Pani Nanofibers ◽  
Combined Use ◽  
Ft Ir ◽  
Thermal Stability Of ◽  
Scanning Electron

The comparison of the influence of CaO and CuO alone and combined CaO/CuO on the diameter, surface morphology and thermal stability of polyaniline (PANI) nanofibers is reported. The possible incorporation of CaO and CuO in PANI was revealed by both fourier transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectroscopy (UV–vis). It was found that the diameter of PANI nanofibers varied for the addition of CaO and CuO alone compared to their combined use. Field emission scanning electron microscopy (FESEM) showed that the addition of CaO, CuO and CaO/CuO consistently produce composite material in nanofibers structures. This nanofibers shows regular and uniform surface morphology and without secondary growth and agglomeration of the primary nanofibers. Thermogravimetric analysis (TGA) data showed better thermal stability for all composite materials as compared to PANI nanofibers.

THE EFFECTS OF TEMPERATURE UPON PANCREATIC AMYLASE IN SELECTED REPTILES AND AN AMPHIBIAN

1967 ◽  
Vol 45 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Yvette Abrahamson ◽  
Michael Maher
Keyword(s):  
Thermal Stability ◽  
Amylase Activity ◽  
Effect Of Temperature ◽  
Maximum Temperature ◽  
Pancreatic Amylase ◽  
Optimum Temperature ◽  
Preferred Temperatures ◽  
Effects Of Temperature ◽  
Subcellular Level ◽  
Thermal Stability Of

The effect of temperature on pancreatic amylase was studied on three species of reptiles and one amphibian. Pancreata were removed from the animals, homogenized, and assayed for amylase activity by the Caraway procedure. Assays were conducted at various temperatures to determine the optimum temperature of activity and the maximum temperature for thermal stability of pancreatic amylase. It appears that between reptiles and amphibians, and also among species of reptiles, there are thermally dependent differences at the subcellular level which are similar to the differences in the preferred temperatures of the animals.

Thermal stability of carbon nitride thin films

2001 ◽  
Vol 16 (11) ◽  
pp. 3188-3201 ◽  
Author(s):  
Niklas Hellgren ◽  
Nian Lin ◽  
Esteban Broitman ◽  
Virginie Serin ◽  
Stefano E. Grillo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Amorphous Structure ◽  
X Ray ◽  
Bonding Structure ◽  
Higher Temperature ◽  
Electron Energy Loss ◽  
Thermal Stability Of

The thermal stability of carbon nitride films, deposited by reactive direct current magnetron sputtering in N2 discharge, was studied for postdeposition annealing temperatures TA up to 1000 °C. Films were grown at temperatures of 100 °C (amorphous structure) and 350 and 550 °C (fullerenelike structure) and were analyzed with respect to thickness, composition, microstructure, bonding structure, and mechanical properties as a function of TA and annealing time. All properties investigated were found to be stable for annealing up to 300 °C for long times (>48 h). For higher TA, nitrogen is lost from the films and graphitization takes place. At TA = 500 °C the graphitization process takes up to 48 h while at TA = 900 °C it takes less than 2 min. A comparison on the evolution of x-ray photoelectron spectroscopy, electron energy loss spectroscopy and Raman spectra during annealing shows that for TA > 800 °C, preferentially pyridinelike N and –C≡N is lost from the films, mainly in the form of molecular N2 and C2N2, while N substituted in graphite is preserved the longest in the structure. Films deposited at the higher temperature exhibit better thermal stability, but annealing at temperatures a few hundred degrees Celsius above the deposition temperature for long times is always detrimental for the mechanical properties of the films.

Effects of Polyaniline Doped by Different Acids on Thermal Stability of Epoxy Resin

2010 ◽  
Vol 160-162 ◽  
pp. 1405-1408 ◽  
Author(s):  
Qing Ming Jia ◽  
Shao Yun Shan ◽  
Li Hong Jiang ◽  
Ya Ming Wang
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Sulfuric Acid ◽  
Epoxy Resin ◽  
Inert Atmosphere ◽  
Pani Nanofibers ◽  
Thermal Stability Of ◽  
Scanning Electron

Polyaniline(PANI) nanofibers were firstly prepared by rapid mixture method, EP/PANI nanocomposite was obtained by in-situ adding the PANI nanofibers to epoxy resin(EP). Scanning electron microscopy(SEM) proves that the type of doped acids has a little effect on the morphologies of PANI, and the PANI doped by different acids present nanofiber structures with the diameter of about 50 nm. The thermal behaviour of EP/PANI nanocomposites were investigated in detail by using a dynamic rate mode of thermogravimetric analyser (TGA) in inert atmosphere, and the results show that the PANI nanofibers obviously improve thermal stability of pure EP. Compared with EP/PANI doped by nitric acid or sulfuric acid, EP/PANI doped by phosphoric acid has best thermal stability.

Photo-Cross-Linking-Assisted Thermal Stability of DNA Origami Structures and Its Application for Higher-Temperature Self-Assembly

2011 ◽  
Vol 133 (37) ◽  
pp. 14488-14491 ◽  
Author(s):  
Arivazhagan Rajendran ◽  
Masayuki Endo ◽  
Yousuke Katsuda ◽  
Kumi Hidaka ◽  
Hiroshi Sugiyama
Keyword(s):  
Thermal Stability ◽  
Self Assembly ◽  
Dna Origami ◽  
Cross Linking ◽  
Higher Temperature ◽  
Thermal Stability Of

Sonochemically Synthesis of Antimonite Nanoparticles and Its Influence on the Thermal Stability of the ABS Terpolymer

2013 ◽  
Vol 32 (4) ◽  
pp. 339-343 ◽  
Author(s):  
Siyamak Bagheriyan
Keyword(s):  
Thermal Stability ◽  
Acrylonitrile Butadiene Styrene ◽  
X Ray Diffraction ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Sonochemical Reaction ◽  
Ft Ir ◽  
Higher Temperature ◽  
Thermal Stability Of ◽  
Butadiene Styrene

AbstractSb2S3 nanoparticles were synthesized via a simple sonochemical reaction between SbCl3 and thioacetamide. The effect of different parameters such as power and time of pulsation on the morphology of the product has been investigated. The Sb2 S3 nanostructures were then added to acrylonitrile-butadiene-styrene terpolymer. The effect of Sb2 S3 nanostructures on the thermal stability of the polymeric matrix has been examined. The thermal decomposition of the nanocomposite shifts towards higher temperature in the presence of the Sb2 S3 . Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), photoluminescence (PL) spectroscopy, thermogravimetric analysis (TGA), UL-94 and limiting oxygen index (LOI) analysis.

Effect of ZnO Nano-Particles on The Dielectric Relaxation Behavior and Thermal Stability of Polycarbonate Host

2011 ◽  
Vol 24 (6) ◽  
pp. 837-852 ◽  
Author(s):  
A.A. Al Jaafari ◽  
A.S. Ayesh
Keyword(s):  
Thermal Stability ◽  
Relaxation Time ◽  
Dielectric Relaxation ◽  
Zno Nanoparticles ◽  
Relaxation Behavior ◽  
Nano Particles ◽  
Effect Of Temperature ◽  
Frequency Range ◽  
Dielectric Relaxation Behavior ◽  
Thermal Stability Of

The influence of ZnO nanoparticles on the dielectric properties, dielectric relaxation behavior, and thermal stability of PC host was investigated at different ZnO nanoparticles concentration. The dielectric study was carried out over a frequency range from 500 Hz up to 1 MHz as a function of ZnO concentration. Results obtained from the best fitting of relative permittivity data with Yan and Rhodes model reveal that the dielectric relaxation is not a single relaxation process and there are two values of relaxation time for each nanocomposite at room temperature and domain frequency range. Furthermore, addition of ZnO nanoparticles to PC host changes the dielectric properties of PC, mainly, increases relative permittivity, dielectric loss, and AC conductivity while decreases the impedance values of PC host. Moreover, effect of temperature on AC conductivity of ZnO-PC nanocomposites at 1 kHz was also considered. Besides, dielectric relaxation behavior of PC was investigated at 165°C (above the glass transition temperature of PC) in the domain frequency range. At this elevated temperature (165°C), dielectric loss data shows a single relaxation peak (α-relaxation) in the domain frequency range and was successfully fitted with Debye equation. Also, it was found that as the content of ZnO nanoparticles increases in the PC host the frequency of the peak maximum ( fmax) shifts toward higher frequency value and as a result decreases the value of relaxation time. Additionally, this study shows that the isothermal effect of ZnO nano particles on the α-relaxation of PC host is similar to the effect of temperature. Both of them have a linear dependence with ln( fmax). Furthermore, addition of ZnO nanoparticles to PC host will decrease the thermal stability and glass transition temperature of PC host. Finally, there is a strong evidence from the obtained dielectric and thermal results that addition of ZnO nanoparticles to PC host will highly enhance the chain mobility and also increase the polar character of PC host.

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