Synthesis and Characterization of Processable Polyimide Titania Nanohybrids

2011 ◽  
Vol 326 ◽  
pp. 88-96 ◽  
Author(s):  
Malik Adnan Saeed ◽  
Zulfiqar H. Lodhi ◽  
Aziz Ullah Khan ◽  
Wasim Asghar

A new aromatic diamine monomer {4-amino [4-(diphenylamino) phenyl] anilino} phenyl amine (DPA -4) were synthesized in high yield and purity. {4-amino [4-(diphenylamino) phenyl] anilino} phenyl amine (DPA -4) monomer were reacted with Tetra carboxylic dianhydride (BT) leading to the formation of polyamic acid, followed by the preparation of polyimide/Titania hybrid films through non-hydrolytic sol-gel method. The synthesized polyimide were considered as blank & compared with the nano-hybrids derived from polyimides/Titania blends of different TiO2content. Synthesized polyimide showed excellent solubility in aprotic solvents like DMF, DMSO, NMP, and DMAC proving best processibility in various applications. Polyimide exhibited excellent thermal stability and its glass transition temperature was 450°C & 5% weight loss is in the range of 500°C~600°C. The thermal stability of Polyimide/Titania composites decreased slightly with increase of TiO2content. Result show decrease in thermal stability of nano-hybrids caused by the decomposition of catalytic activity of Titania & incomplete imidizations of polyamic acid. The absorption band of PI-O-Ti bonds in FTIR spectra of hybrids films revealed the formation of hybrid inorganic network between polyimide and TiO2.Scanning electron microscopy results indicated that the nanometer-scaled inorganic domains were homogeneously dispersed in polyimides matrix due to the introduction of TiO2.The studies on the optical properties of hybrids films indicated the red-shift to the absorption band increased with increasing TiO2content, while all the hybrids films maintained their transparencies. This kind of hybrid materials has potential commercial application in the field of opto-electronics appliances.

2021 ◽  
Author(s):  
Ahlem Bendaoued ◽  
Mouna Messaoud ◽  
Omar Harzallah ◽  
Sophie Bistac ◽  
Rached Salhi

Abstract Ceramics nanometric reinforced polymer composite is a significant material for catalysis, solar cells, production of hydrogen and energy applications, etc. In order to take benefit from the interesting mechanical properties and thermal stability of TiO2, these ceramic nanomaterials was synthesized by the Sol-Gel process in attempt to study the thermal stability, structure, and morphology of the resulting nanoparticles powders. The obtained results revealed that, the sphere is composed of 20-30 nm nanoparticles with excellent thermal stability of nano-TiO2. This work focused on the thermal characterization and the study of nanocomposite xWt. %TiO2/PP (x=0, 2.5, 5, 7.5 mol%). In this study, the obtained results revealed that the molar ratio of TiO2 influences the final thermal stability and degree of crystallinity of the composite. It was found that the use of TiO2 seems to be an effective and very promising way to increase the thermal properties of the resulting composite. The greatest degree of crystallinity (54.80%) and thermal degradation stability are obtained for composite reinforced by 7.5Wt. %TiO2.


Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.


2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060018
Author(s):  
E. M. Bayan ◽  
T. G. Lupeiko ◽  
L. E. Pustovaya ◽  
M. G. Volkova

Sn-doped TiO2 nanomaterials were synthesized by sol–gel method. It was shown the phase compositions and phase transitions change with the introduction of different tin amounts (0.5–20[Formula: see text]mol.%). X-ray powder diffraction was used to study the effect of different tin amounts on the anatase–rutile phase transition. It was found that the introduction of ions increases the thermal stability of anatase modifications. The material’s photocatalytic activity was studied in reaction with a model pollutant (methylene blue) photodegradation under UV and visible light activation. The best photocatalytic properties were shown for material, which contains 5[Formula: see text]mol.% of Sn.


2009 ◽  
Vol 480 (2) ◽  
pp. 908-911 ◽  
Author(s):  
E. Kin ◽  
T. Fukuda ◽  
S. Yamauchi ◽  
Z. Honda ◽  
H. Ohara ◽  
...  

2012 ◽  
Vol 512-515 ◽  
pp. 1018-1021
Author(s):  
Xu Fei Zhu ◽  
Long Fei Jiang ◽  
Wei Xing Qi ◽  
Chao Lu ◽  
Ye Song

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.


MRS Advances ◽  
2016 ◽  
Vol 1 (41) ◽  
pp. 2807-2813 ◽  
Author(s):  
Atasi Dan ◽  
Kamanio Chattopadhyay ◽  
Harish C. Barshilia ◽  
Bikramjit Basu

AbstractThe solar absorptance property of W/WAlN/WAlON/Al2O3-based coatings, deposited by DC/RF magnetron sputtering on stainless steel substrate was studied by measuring the reflectance spectra in the wavelength range of 250 - 2500 nm. The effect of thermal annealing on the optical properties of the solar selective absorber coatings was investigated. Annealing the coatings at 450°C for 150 hrs in air did not show any significant change in the spectral properties of the absorber coating indicating the excellent thermal stability of the coating. The W layer acts as infrared reflective layer and diffusion barrier on stainless steel substrate. The top Al2O3 layer serves as dense shield to protect the under layers from oxidation in air. In summary, the present study indicates the potential application of W/WAlN/WAlON/Al2O3-based selective coatings in high temperature photo thermal conversion systems.


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